wishthis/semantic/dist/components/form.js

/*!
 * # Fomantic-UI 2.9.3 - Form Validation
 * https://github.com/fomantic/Fomantic-UI/
 *
 *
 * Released under the MIT license
 * https://opensource.org/licenses/MIT
 *
 */

(function ($, window, document) {
    'use strict';

    function isFunction(obj) {
        return typeof obj === 'function' && typeof obj.nodeType !== 'number';
    }

    window = window !== undefined && window.Math === Math
        ? window
        : globalThis;

    $.fn.form = function (parameters) {
        var
            $allModules      = $(this),
            moduleSelector   = $allModules.selector || '',

            time             = Date.now(),
            performance      = [],

            query            = arguments[0],
            methodInvoked    = typeof query === 'string',
            queryArguments   = [].slice.call(arguments, 1),
            returnedValue
        ;
        $allModules.each(function () {
            var
                $module     = $(this),
                element     = this,

                formErrors  = [],
                keyHeldDown = false,

                // set at run-time
                $field,
                $group,
                $message,
                $prompt,
                $submit,
                $clear,
                $reset,

                settings,
                validation,

                metadata,
                selector,
                className,
                regExp,
                error,

                namespace,
                moduleNamespace,
                eventNamespace,

                submitting = false,
                dirty = false,
                history = ['clean', 'clean'],

                instance,
                module
            ;

            module = {

                initialize: function () {
                    // settings grabbed at run time
                    module.get.settings();
                    if (methodInvoked) {
                        if (instance === undefined) {
                            module.instantiate();
                        }
                        module.invoke(query);
                    } else {
                        if (instance !== undefined) {
                            instance.invoke('destroy');
                            module.refresh();
                        }
                        module.verbose('Initializing form validation', $module, settings);
                        module.bindEvents();
                        module.set.defaults();
                        if (settings.autoCheckRequired) {
                            module.set.autoCheck();
                        }
                        module.instantiate();
                    }
                },

                instantiate: function () {
                    module.verbose('Storing instance of module', module);
                    instance = module;
                    $module
                        .data(moduleNamespace, module)
                    ;
                },

                destroy: function () {
                    module.verbose('Destroying previous module', instance);
                    module.removeEvents();
                    $module
                        .removeData(moduleNamespace)
                    ;
                },

                refresh: function () {
                    module.verbose('Refreshing selector cache');
                    $field = $module.find(selector.field);
                    $group = $module.find(selector.group);
                    $message = $module.find(selector.message);
                    $prompt = $module.find(selector.prompt);

                    $submit = $module.find(selector.submit);
                    $clear = $module.find(selector.clear);
                    $reset = $module.find(selector.reset);
                },

                refreshEvents: function () {
                    module.removeEvents();
                    module.bindEvents();
                },

                submit: function () {
                    module.verbose('Submitting form', $module);
                    submitting = true;
                    $module.trigger('submit');
                },

                attachEvents: function (selector, action) {
                    if (!action) {
                        action = 'submit';
                    }

                    $(selector).on('click' + eventNamespace, function (event) {
                        module[action]();
                        event.preventDefault();
                    });
                },

                bindEvents: function () {
                    module.verbose('Attaching form events');
                    $module
                        .on('submit' + eventNamespace, module.validate.form)
                        .on('blur' + eventNamespace, selector.field, module.event.field.blur)
                        .on('click' + eventNamespace, selector.submit, module.submit)
                        .on('click' + eventNamespace, selector.reset, module.reset)
                        .on('click' + eventNamespace, selector.clear, module.clear)
                    ;
                    if (settings.keyboardShortcuts) {
                        $module.on('keydown' + eventNamespace, selector.field, module.event.field.keydown);
                    }
                    $field.each(function (index, el) {
                        var
                            $input     = $(el),
                            type       = $input.prop('type'),
                            inputEvent = module.get.changeEvent(type, $input)
                        ;
                        $input.on(inputEvent + eventNamespace, module.event.field.change);
                    });

                    // Dirty events
                    if (settings.preventLeaving) {
                        $(window).on('beforeunload' + eventNamespace, module.event.beforeUnload);
                    }

                    $field.on('change click keyup keydown blur', function (e) {
                        module.determine.isDirty();
                    });

                    $module.on('dirty' + eventNamespace, function (e) {
                        settings.onDirty.call();
                    });

                    $module.on('clean' + eventNamespace, function (e) {
                        settings.onClean.call();
                    });
                },

                clear: function () {
                    $field.each(function (index, el) {
                        var
                            $field       = $(el),
                            $element     = $field.parent(),
                            $fieldGroup  = $field.closest($group),
                            $prompt      = $fieldGroup.find(selector.prompt),
                            $calendar    = $field.closest(selector.uiCalendar),
                            defaultValue = $field.data(metadata.defaultValue) || '',
                            isCheckbox   = $field.is(selector.checkbox),
                            isDropdown   = $element.is(selector.uiDropdown) && module.can.useElement('dropdown'),
                            isCalendar   = $calendar.length > 0 && module.can.useElement('calendar'),
                            isErrored    = $fieldGroup.hasClass(className.error)
                        ;
                        if (isErrored) {
                            module.verbose('Resetting error on field', $fieldGroup);
                            $fieldGroup.removeClass(className.error);
                            $prompt.remove();
                        }
                        if (isDropdown) {
                            module.verbose('Resetting dropdown value', $element, defaultValue);
                            $element.dropdown('clear', true);
                        } else if (isCheckbox) {
                            $field.prop('checked', false);
                        } else if (isCalendar) {
                            $calendar.calendar('clear');
                        } else {
                            module.verbose('Resetting field value', $field, defaultValue);
                            $field.val('');
                        }
                    });
                    module.remove.states();
                },

                reset: function () {
                    $field.each(function (index, el) {
                        var
                            $field       = $(el),
                            $element     = $field.parent(),
                            $fieldGroup  = $field.closest($group),
                            $calendar    = $field.closest(selector.uiCalendar),
                            $prompt      = $fieldGroup.find(selector.prompt),
                            defaultValue = $field.data(metadata.defaultValue),
                            isCheckbox   = $field.is(selector.checkbox),
                            isDropdown   = $element.is(selector.uiDropdown) && module.can.useElement('dropdown'),
                            isCalendar   = $calendar.length > 0 && module.can.useElement('calendar'),
                            isErrored    = $fieldGroup.hasClass(className.error)
                        ;
                        if (defaultValue === undefined) {
                            return;
                        }
                        if (isErrored) {
                            module.verbose('Resetting error on field', $fieldGroup);
                            $fieldGroup.removeClass(className.error);
                            $prompt.remove();
                        }
                        if (isDropdown) {
                            module.verbose('Resetting dropdown value', $element, defaultValue);
                            $element.dropdown('restore defaults', true);
                        } else if (isCheckbox) {
                            module.verbose('Resetting checkbox value', $field, defaultValue);
                            $field.prop('checked', defaultValue);
                        } else if (isCalendar) {
                            $calendar.calendar('set date', defaultValue);
                        } else {
                            module.verbose('Resetting field value', $field, defaultValue);
                            $field.val(defaultValue);
                        }
                    });
                    module.remove.states();
                },

                determine: {
                    isValid: function () {
                        var
                            allValid = true
                        ;
                        $.each(validation, function (fieldName, field) {
                            if (!module.validate.field(field, fieldName, true)) {
                                allValid = false;
                            }
                        });

                        return allValid;
                    },
                    isDirty: function (e) {
                        var formIsDirty = false;

                        $field.each(function (index, el) {
                            var
                                $el = $(el),
                                isCheckbox = $el.filter(selector.checkbox).length > 0,
                                isDirty
                            ;

                            isDirty = isCheckbox
                                ? module.is.checkboxDirty($el)
                                : module.is.fieldDirty($el);

                            $el.data(settings.metadata.isDirty, isDirty);

                            formIsDirty = formIsDirty || isDirty;
                        });

                        if (formIsDirty) {
                            module.set.dirty();
                        } else {
                            module.set.clean();
                        }
                    },
                },

                is: {
                    bracketedRule: function (rule) {
                        return rule.type && rule.type.match(settings.regExp.bracket);
                    },
                    // duck type rule test
                    shorthandRules: function (rules) {
                        return typeof rules === 'string' || Array.isArray(rules);
                    },
                    empty: function ($field) {
                        if (!$field || $field.length === 0) {
                            return true;
                        }
                        if ($field.is(selector.checkbox)) {
                            return !$field.is(':checked');
                        }

                        return module.is.blank($field);
                    },
                    blank: function ($field) {
                        return String($field.val()).trim() === '';
                    },
                    valid: function (field, showErrors) {
                        var
                            allValid = true
                        ;
                        if (field) {
                            module.verbose('Checking if field is valid', field);

                            return module.validate.field(validation[field], field, !!showErrors);
                        }

                        module.verbose('Checking if form is valid');
                        $.each(validation, function (fieldName, field) {
                            if (!module.is.valid(fieldName, showErrors)) {
                                allValid = false;
                            }
                        });

                        return allValid;
                    },
                    dirty: function () {
                        return dirty;
                    },
                    clean: function () {
                        return !dirty;
                    },
                    fieldDirty: function ($el) {
                        var initialValue = $el.data(metadata.defaultValue);
                        // Explicitly check for undefined/null here as value may be `false`, so ($el.data(dataInitialValue) || '') would not work
                        if (initialValue === undefined || initialValue === null) {
                            initialValue = '';
                        } else if (Array.isArray(initialValue)) {
                            initialValue = initialValue.toString();
                        }
                        var currentValue = $el.val();
                        if (currentValue === undefined || currentValue === null) {
                            currentValue = '';
                        } else if (Array.isArray(currentValue)) {
                            // multiple select values are returned as arrays which are never equal, so do string conversion first
                            currentValue = currentValue.toString();
                        }
                        // Boolean values can be encoded as "true/false" or "True/False" depending on underlying frameworks so we need a case insensitive comparison
                        var boolRegex = /^(true|false)$/i;
                        var isBoolValue = boolRegex.test(initialValue) && boolRegex.test(currentValue);
                        if (isBoolValue) {
                            var regex = new RegExp('^' + initialValue + '$', 'i');

                            return !regex.test(currentValue);
                        }

                        return currentValue !== initialValue;
                    },
                    checkboxDirty: function ($el) {
                        var initialValue = $el.data(metadata.defaultValue);
                        var currentValue = $el.is(':checked');

                        return initialValue !== currentValue;
                    },
                    justDirty: function () {
                        return history[0] === 'dirty';
                    },
                    justClean: function () {
                        return history[0] === 'clean';
                    },
                },

                removeEvents: function () {
                    $module.off(eventNamespace);
                    $field.off(eventNamespace);
                    $submit.off(eventNamespace);
                },

                event: {
                    field: {
                        keydown: function (event) {
                            var
                                $field       = $(this),
                                key          = event.which,
                                isInput      = $field.is(selector.input),
                                isCheckbox   = $field.is(selector.checkbox),
                                isInDropdown = $field.closest(selector.uiDropdown).length > 0,
                                keyCode      = {
                                    enter: 13,
                                    escape: 27,
                                }
                            ;
                            if (key === keyCode.escape) {
                                module.verbose('Escape key pressed blurring field');
                                $field[0]
                                    .blur()
                                ;
                            }
                            if (!event.ctrlKey && key === keyCode.enter && isInput && !isInDropdown && !isCheckbox) {
                                if (!keyHeldDown) {
                                    $field.one('keyup' + eventNamespace, module.event.field.keyup);
                                    module.submit();
                                    module.debug('Enter pressed on input submitting form');
                                    event.preventDefault();
                                }
                                keyHeldDown = true;
                            }
                        },
                        keyup: function () {
                            keyHeldDown = false;
                        },
                        blur: function (event) {
                            var
                                $field          = $(this),
                                $fieldGroup     = $field.closest($group),
                                validationRules = module.get.validation($field)
                            ;
                            if (validationRules && (settings.on === 'blur' || ($fieldGroup.hasClass(className.error) && settings.revalidate))) {
                                module.debug('Revalidating field', $field, validationRules);
                                module.validate.field(validationRules);
                                if (!settings.inline) {
                                    module.validate.form(false, true);
                                }
                            }
                        },
                        change: function (event) {
                            var
                                $field      = $(this),
                                $fieldGroup = $field.closest($group),
                                validationRules = module.get.validation($field)
                            ;
                            if (validationRules && (settings.on === 'change' || ($fieldGroup.hasClass(className.error) && settings.revalidate))) {
                                clearTimeout(module.timer);
                                module.timer = setTimeout(function () {
                                    module.debug('Revalidating field', $field, validationRules);
                                    module.validate.field(validationRules);
                                    if (!settings.inline) {
                                        module.validate.form(false, true);
                                    }
                                }, settings.delay);
                            }
                        },
                    },
                    beforeUnload: function (event) {
                        if (module.is.dirty() && !submitting) {
                            event = event || window.event;

                            // For modern browsers
                            if (event) {
                                event.returnValue = settings.text.leavingMessage;
                            }

                            // For olders...
                            return settings.text.leavingMessage;
                        }
                    },

                },

                get: {
                    ancillaryValue: function (rule) {
                        if (!rule.type || (!rule.value && !module.is.bracketedRule(rule))) {
                            return false;
                        }

                        return rule.value !== undefined
                            ? rule.value
                            : rule.type.match(settings.regExp.bracket)[1] + '';
                    },
                    ruleName: function (rule) {
                        if (module.is.bracketedRule(rule)) {
                            return rule.type.replace(rule.type.match(settings.regExp.bracket)[0], '');
                        }

                        return rule.type;
                    },
                    changeEvent: function (type, $input) {
                        if (type === 'checkbox' || type === 'radio' || type === 'hidden' || $input.is('select')) {
                            return 'change';
                        }

                        return module.get.inputEvent();
                    },
                    inputEvent: function () {
                        return document.createElement('input').oninput !== undefined
                            ? 'input'
                            : (document.createElement('input').onpropertychange !== undefined
                                ? 'propertychange'
                                : 'keyup');
                    },
                    fieldsFromShorthand: function (fields) {
                        var
                            fullFields = {}
                        ;
                        $.each(fields, function (name, rules) {
                            if (!Array.isArray(rules) && typeof rules === 'object') {
                                fullFields[name] = rules;
                            } else {
                                if (typeof rules === 'string') {
                                    rules = [rules];
                                }
                                fullFields[name] = {
                                    rules: [],
                                };
                                $.each(rules, function (index, rule) {
                                    fullFields[name].rules.push({ type: rule });
                                });
                            }
                        });

                        return fullFields;
                    },
                    prompt: function (rule, field) {
                        var
                            ruleName      = module.get.ruleName(rule),
                            ancillary     = module.get.ancillaryValue(rule),
                            $field        = module.get.field(field.identifier),
                            value         = $field.val(),
                            prompt        = isFunction(rule.prompt)
                                ? rule.prompt(value)
                                : rule.prompt || settings.prompt[ruleName] || settings.text.unspecifiedRule,
                            requiresValue = prompt.search('{value}') !== -1,
                            requiresName  = prompt.search('{name}') !== -1,
                            parts,
                            suffixPrompt
                        ;
                        if (ancillary && ['integer', 'decimal', 'number', 'size'].indexOf(ruleName) >= 0 && ancillary.indexOf('..') >= 0) {
                            parts = ancillary.split('..', 2);
                            if (!rule.prompt && ruleName !== 'size') {
                                suffixPrompt = parts[0] === ''
                                    ? settings.prompt.maxValue.replace(/{ruleValue}/g, '{max}')
                                    : (parts[1] === ''
                                        ? settings.prompt.minValue.replace(/{ruleValue}/g, '{min}')
                                        : settings.prompt.range);
                                prompt += suffixPrompt.replace(/{name}/g, ' ' + settings.text.and);
                            }
                            prompt = prompt.replace(/{min}/g, parts[0]);
                            prompt = prompt.replace(/{max}/g, parts[1]);
                        }
                        if (ancillary && ['match', 'different'].indexOf(ruleName) >= 0) {
                            prompt = prompt.replace(/{ruleValue}/g, module.get.fieldLabel(ancillary, true));
                        }
                        if (requiresValue) {
                            prompt = prompt.replace(/{value}/g, $field.val());
                        }
                        if (requiresName) {
                            prompt = prompt.replace(/{name}/g, module.get.fieldLabel($field));
                        }
                        prompt = prompt.replace(/{identifier}/g, field.identifier);
                        prompt = prompt.replace(/{ruleValue}/g, ancillary);
                        if (!rule.prompt) {
                            module.verbose('Using default validation prompt for type', prompt, ruleName);
                        }

                        return prompt;
                    },
                    settings: function () {
                        if ($.isPlainObject(parameters)) {
                            if (parameters.fields) {
                                parameters.fields = module.get.fieldsFromShorthand(parameters.fields);
                            }
                            settings = $.extend(true, {}, $.fn.form.settings, parameters);
                            validation = $.extend(true, {}, $.fn.form.settings.defaults, settings.fields);
                            module.verbose('Extending settings', validation, settings);
                        } else {
                            settings = $.extend(true, {}, $.fn.form.settings);
                            validation = $.extend(true, {}, $.fn.form.settings.defaults);
                            module.verbose('Using default form validation', validation, settings);
                        }

                        // shorthand
                        namespace = settings.namespace;
                        metadata = settings.metadata;
                        selector = settings.selector;
                        className = settings.className;
                        regExp = settings.regExp;
                        error = settings.error;
                        moduleNamespace = 'module-' + namespace;
                        eventNamespace = '.' + namespace;

                        // grab instance
                        instance = $module.data(moduleNamespace);

                        // refresh selector cache
                        (instance || module).refresh();
                    },
                    field: function (identifier, strict) {
                        module.verbose('Finding field with identifier', identifier);
                        identifier = module.escape.string(identifier);
                        var t;
                        t = $field.filter('#' + identifier);
                        if (t.length > 0) {
                            return t;
                        }
                        t = $field.filter('[name="' + identifier + '"]');
                        if (t.length > 0) {
                            return t;
                        }
                        t = $field.filter('[name="' + identifier + '[]"]');
                        if (t.length > 0) {
                            return t;
                        }
                        t = $field.filter('[data-' + metadata.validate + '="' + identifier + '"]');
                        if (t.length > 0) {
                            return t;
                        }
                        module.error(error.noField.replace('{identifier}', identifier));

                        return strict ? $() : $('<input/>');
                    },
                    fields: function (fields, strict) {
                        var
                            $fields = $()
                        ;
                        $.each(fields, function (index, name) {
                            $fields = $fields.add(module.get.field(name, strict));
                        });

                        return $fields;
                    },
                    fieldLabel: function (identifier, useIdAsFallback) {
                        var $field = typeof identifier === 'string'
                                ? module.get.field(identifier)
                                : identifier,
                            $label = $field.closest(selector.group).find('label').eq(0)
                        ;

                        return $label.length === 1
                            ? $label.text()
                            : $field.prop('placeholder') || (useIdAsFallback ? identifier : settings.text.unspecifiedField);
                    },
                    validation: function ($field) {
                        var
                            fieldValidation,
                            identifier
                        ;
                        if (!validation) {
                            return false;
                        }
                        $.each(validation, function (fieldName, field) {
                            identifier = field.identifier || fieldName;
                            $.each(module.get.field(identifier), function (index, groupField) {
                                if (groupField == $field[0]) {
                                    field.identifier = identifier;
                                    fieldValidation = field;

                                    return false;
                                }
                            });
                        });

                        return fieldValidation || false;
                    },
                    value: function (field, strict) {
                        var
                            fields = [],
                            results,
                            resultKeys
                        ;
                        fields.push(field);
                        results = module.get.values.call(element, fields, strict);
                        resultKeys = Object.keys(results);

                        return resultKeys.length > 0 ? results[resultKeys[0]] : undefined;
                    },
                    values: function (fields, strict) {
                        var
                            $fields = Array.isArray(fields) && fields.length > 0
                                ? module.get.fields(fields, strict)
                                : $field,
                            values = {}
                        ;
                        $fields.each(function (index, field) {
                            var
                                $field       = $(field),
                                $calendar    = $field.closest(selector.uiCalendar),
                                name         = $field.prop('name'),
                                value        = $field.val(),
                                isCheckbox   = $field.is(selector.checkbox),
                                isRadio      = $field.is(selector.radio),
                                isMultiple   = name.indexOf('[]') !== -1,
                                isCalendar   = $calendar.length > 0 && module.can.useElement('calendar'),
                                isChecked    = isCheckbox
                                    ? $field.is(':checked')
                                    : false
                            ;
                            if (name) {
                                if (isMultiple) {
                                    name = name.replace('[]', '');
                                    if (!values[name]) {
                                        values[name] = [];
                                    }
                                    if (isCheckbox) {
                                        if (isChecked) {
                                            values[name].push(value || true);
                                        } else {
                                            values[name].push(false);
                                        }
                                    } else {
                                        values[name].push(value);
                                    }
                                } else {
                                    if (isRadio) {
                                        if (values[name] === undefined || values[name] === false) {
                                            values[name] = isChecked
                                                ? value || true
                                                : false;
                                        }
                                    } else if (isCheckbox) {
                                        values[name] = isChecked ? value || true : false;
                                    } else if (isCalendar) {
                                        var date = $calendar.calendar('get date');

                                        if (date !== null) {
                                            switch (settings.dateHandling) {
                                                case 'date': {
                                                    values[name] = date;

                                                    break;
                                                }
                                                case 'input': {
                                                    values[name] = $calendar.calendar('get input date');

                                                    break;
                                                }
                                                case 'formatter': {
                                                    var type = $calendar.calendar('setting', 'type');

                                                    switch (type) {
                                                        case 'date': {
                                                            values[name] = settings.formatter.date(date);

                                                            break;
                                                        }
                                                        case 'datetime': {
                                                            values[name] = settings.formatter.datetime(date);

                                                            break;
                                                        }
                                                        case 'time': {
                                                            values[name] = settings.formatter.time(date);

                                                            break;
                                                        }
                                                        case 'month': {
                                                            values[name] = settings.formatter.month(date);

                                                            break;
                                                        }
                                                        case 'year': {
                                                            values[name] = settings.formatter.year(date);

                                                            break;
                                                        }
                                                        default: {
                                                            module.debug('Wrong calendar mode', $calendar, type);
                                                            values[name] = '';
                                                        }
                                                    }

                                                    break;
                                                }
                                            }
                                        } else {
                                            values[name] = '';
                                        }
                                    } else {
                                        values[name] = value;
                                    }
                                }
                            }
                        });

                        return values;
                    },
                    dirtyFields: function () {
                        return $field.filter(function (index, e) {
                            return $(e).data(metadata.isDirty);
                        });
                    },
                },

                has: {

                    field: function (identifier) {
                        module.verbose('Checking for existence of a field with identifier', identifier);

                        return module.get.field(identifier, true).length > 0;
                    },

                },

                can: {
                    useElement: function (element) {
                        if ($.fn[element] !== undefined) {
                            return true;
                        }
                        module.error(error.noElement.replace('{element}', element));

                        return false;
                    },
                },

                escape: {
                    string: function (text) {
                        text = String(text);

                        return text.replace(regExp.escape, '\\$&');
                    },
                },

                checkErrors: function (errors, internal) {
                    if (!errors || errors.length === 0) {
                        if (!internal) {
                            module.error(settings.error.noErrorMessage);
                        }

                        return false;
                    }
                    if (!internal) {
                        errors = typeof errors === 'string'
                            ? [errors]
                            : errors;
                    }

                    return errors;
                },
                add: {
                    // alias
                    rule: function (name, rules) {
                        module.add.field(name, rules);
                    },
                    field: function (name, rules) {
                        // Validation should have at least a standard format
                        if (validation[name] === undefined || validation[name].rules === undefined) {
                            validation[name] = {
                                rules: [],
                            };
                        }
                        var
                            newValidation = {
                                rules: [],
                            }
                        ;
                        if (module.is.shorthandRules(rules)) {
                            rules = Array.isArray(rules)
                                ? rules
                                : [rules];
                            $.each(rules, function (_index, rule) {
                                newValidation.rules.push({ type: rule });
                            });
                        } else {
                            newValidation.rules = rules.rules;
                        }
                        // For each new rule, check if there's not already one with the same type
                        $.each(newValidation.rules, function (_index, rule) {
                            if ($.grep(validation[name].rules, function (item) {
                                return item.type === rule.type;
                            }).length === 0) {
                                validation[name].rules.push(rule);
                            }
                        });
                        module.debug('Adding rules', newValidation.rules, validation);
                        module.refreshEvents();
                    },
                    fields: function (fields) {
                        validation = $.extend(true, {}, validation, module.get.fieldsFromShorthand(fields));
                        module.refreshEvents();
                    },
                    prompt: function (identifier, errors, internal) {
                        errors = module.checkErrors(errors);
                        if (errors === false) {
                            return;
                        }
                        var
                            $field       = module.get.field(identifier),
                            $fieldGroup  = $field.closest($group),
                            $prompt      = $fieldGroup.children(selector.prompt),
                            promptExists = $prompt.length > 0
                        ;
                        module.verbose('Adding field error state', identifier);
                        if (!internal) {
                            $fieldGroup
                                .addClass(className.error)
                            ;
                        }
                        if (settings.inline) {
                            if (!promptExists) {
                                $prompt = $('<div/>').addClass(className.label);
                                $prompt
                                    .appendTo($fieldGroup)
                                ;
                            }
                            $prompt
                                .html(settings.templates.prompt(errors))
                            ;
                            if (!promptExists) {
                                if (settings.transition && module.can.useElement('transition')) {
                                    module.verbose('Displaying error with css transition', settings.transition);
                                    $prompt.transition(settings.transition + ' in', settings.duration);
                                } else {
                                    module.verbose('Displaying error with fallback javascript animation');
                                    $prompt
                                        .fadeIn(settings.duration)
                                    ;
                                }
                            } else {
                                module.verbose('Inline errors are disabled, no inline error added', identifier);
                            }
                        }
                    },
                    errors: function (errors) {
                        errors = module.checkErrors(errors);
                        if (errors === false) {
                            return;
                        }
                        module.debug('Adding form error messages', errors);
                        module.set.error();
                        var customErrors = [],
                            tempErrors
                        ;
                        if ($.isPlainObject(errors)) {
                            $.each(Object.keys(errors), function (i, id) {
                                if (module.checkErrors(errors[id], true) !== false) {
                                    if (settings.inline) {
                                        module.add.prompt(id, errors[id]);
                                    } else {
                                        tempErrors = module.checkErrors(errors[id]);
                                        if (tempErrors !== false) {
                                            $.each(tempErrors, function (index, tempError) {
                                                customErrors.push(settings.prompt.addErrors
                                                    .replace(/{name}/g, module.get.fieldLabel(id))
                                                    .replace(/{error}/g, tempError));
                                            });
                                        }
                                    }
                                }
                            });
                        } else {
                            customErrors = errors;
                        }
                        if (customErrors.length > 0) {
                            $message
                                .html(settings.templates.error(customErrors))
                            ;
                        }
                    },
                },

                remove: {
                    errors: function () {
                        module.debug('Removing form error messages');
                        $message.empty();
                    },
                    states: function () {
                        $module.removeClass(className.error).removeClass(className.success);
                        if (!settings.inline) {
                            module.remove.errors();
                        }
                        module.determine.isDirty();
                    },
                    rule: function (field, rule) {
                        var
                            rules = Array.isArray(rule)
                                ? rule
                                : [rule]
                        ;
                        if (validation[field] === undefined || !Array.isArray(validation[field].rules)) {
                            return;
                        }
                        if (rule === undefined) {
                            module.debug('Removed all rules');
                            if (module.has.field(field)) {
                                validation[field].rules = [];
                            } else {
                                delete validation[field];
                            }

                            return;
                        }
                        $.each(validation[field].rules, function (index, rule) {
                            if (rule && rules.indexOf(rule.type) !== -1) {
                                module.debug('Removed rule', rule.type);
                                validation[field].rules.splice(index, 1);
                            }
                        });
                    },
                    field: function (field) {
                        var
                            fields = Array.isArray(field)
                                ? field
                                : [field]
                        ;
                        $.each(fields, function (index, field) {
                            module.remove.rule(field);
                        });
                        module.refreshEvents();
                    },
                    // alias
                    rules: function (field, rules) {
                        if (Array.isArray(field)) {
                            $.each(field, function (index, field) {
                                module.remove.rule(field, rules);
                            });
                        } else {
                            module.remove.rule(field, rules);
                        }
                    },
                    fields: function (fields) {
                        module.remove.field(fields);
                    },
                    prompt: function (identifier) {
                        var
                            $field      = module.get.field(identifier),
                            $fieldGroup = $field.closest($group),
                            $prompt     = $fieldGroup.children(selector.prompt)
                        ;
                        $fieldGroup
                            .removeClass(className.error)
                        ;
                        if (settings.inline && $prompt.is(':visible')) {
                            module.verbose('Removing prompt for field', identifier);
                            if (settings.transition && module.can.useElement('transition')) {
                                $prompt.transition(settings.transition + ' out', settings.duration, function () {
                                    $prompt.remove();
                                });
                            } else {
                                $prompt
                                    .fadeOut(settings.duration, function () {
                                        $prompt.remove();
                                    })
                                ;
                            }
                        }
                    },
                },

                set: {
                    success: function () {
                        $module
                            .removeClass(className.error)
                            .addClass(className.success)
                        ;
                    },
                    defaults: function () {
                        $field.each(function (index, el) {
                            var
                                $el        = $(el),
                                $parent    = $el.parent(),
                                isCheckbox = $el.filter(selector.checkbox).length > 0,
                                isDropdown = ($parent.is(selector.uiDropdown) || $el.is(selector.uiDropdown)) && module.can.useElement('dropdown'),
                                $calendar  = $el.closest(selector.uiCalendar),
                                isCalendar = $calendar.length > 0 && module.can.useElement('calendar'),
                                value      = isCheckbox
                                    ? $el.is(':checked')
                                    : $el.val()
                            ;
                            if (isDropdown) {
                                if ($parent.is(selector.uiDropdown)) {
                                    $parent.dropdown('save defaults');
                                } else {
                                    $el.dropdown('save defaults');
                                }
                            } else if (isCalendar) {
                                $calendar.calendar('refresh');
                            }
                            $el.data(metadata.defaultValue, value);
                            $el.data(metadata.isDirty, false);
                        });
                    },
                    error: function () {
                        $module
                            .removeClass(className.success)
                            .addClass(className.error)
                        ;
                    },
                    value: function (field, value) {
                        var
                            fields = {}
                        ;
                        fields[field] = value;

                        return module.set.values.call(element, fields);
                    },
                    values: function (fields) {
                        if ($.isEmptyObject(fields)) {
                            return;
                        }
                        $.each(fields, function (key, value) {
                            var
                                $field      = module.get.field(key),
                                $element    = $field.parent(),
                                $calendar   = $field.closest(selector.uiCalendar),
                                isMultiple  = Array.isArray(value),
                                isCheckbox  = $element.is(selector.uiCheckbox) && module.can.useElement('checkbox'),
                                isDropdown  = $element.is(selector.uiDropdown) && module.can.useElement('dropdown'),
                                isRadio     = $field.is(selector.radio) && isCheckbox,
                                isCalendar  = $calendar.length > 0 && module.can.useElement('calendar'),
                                fieldExists = $field.length > 0,
                                $multipleField
                            ;
                            if (fieldExists) {
                                if (isMultiple && isCheckbox) {
                                    module.verbose('Selecting multiple', value, $field);
                                    $element.checkbox('uncheck');
                                    $.each(value, function (index, value) {
                                        $multipleField = $field.filter('[value="' + value + '"]');
                                        $element = $multipleField.parent();
                                        if ($multipleField.length > 0) {
                                            $element.checkbox('check');
                                        }
                                    });
                                } else if (isRadio) {
                                    module.verbose('Selecting radio value', value, $field);
                                    $field.filter('[value="' + value + '"]')
                                        .parent(selector.uiCheckbox)
                                        .checkbox('check')
                                    ;
                                } else if (isCheckbox) {
                                    module.verbose('Setting checkbox value', value, $element);
                                    if (value === true || value === 1 || value === 'on') {
                                        $element.checkbox('check');
                                    } else {
                                        $element.checkbox('uncheck');
                                    }
                                    if (typeof value === 'string') {
                                        $field.val(value);
                                    }
                                } else if (isDropdown) {
                                    module.verbose('Setting dropdown value', value, $element);
                                    $element.dropdown('set selected', value);
                                } else if (isCalendar) {
                                    $calendar.calendar('set date', value);
                                } else {
                                    module.verbose('Setting field value', value, $field);
                                    $field.val(value);
                                }
                            }
                        });
                    },
                    dirty: function () {
                        module.verbose('Setting state dirty');
                        dirty = true;
                        history[0] = history[1];
                        history[1] = 'dirty';

                        if (module.is.justClean()) {
                            $module.trigger('dirty');
                        }
                    },
                    clean: function () {
                        module.verbose('Setting state clean');
                        dirty = false;
                        history[0] = history[1];
                        history[1] = 'clean';

                        if (module.is.justDirty()) {
                            $module.trigger('clean');
                        }
                    },
                    asClean: function () {
                        module.set.defaults();
                        module.set.clean();
                    },
                    asDirty: function () {
                        module.set.defaults();
                        module.set.dirty();
                    },
                    autoCheck: function () {
                        module.debug('Enabling auto check on required fields');
                        if (validation) {
                            $.each(validation, function (fieldName) {
                                if (!module.has.field(fieldName)) {
                                    module.verbose('Field not found, removing from validation', fieldName);
                                    module.remove.field(fieldName);
                                }
                            });
                        }
                        $field.each(function (_index, el) {
                            var
                                $el        = $(el),
                                $elGroup   = $el.closest($group),
                                isCheckbox = $el.filter(selector.checkbox).length > 0,
                                isRequired = $el.prop('required') || $elGroup.hasClass(className.required) || $elGroup.parent().hasClass(className.required),
                                isDisabled = $el.is(':disabled') || $elGroup.hasClass(className.disabled) || $elGroup.parent().hasClass(className.disabled),
                                validation = module.get.validation($el),
                                hasEmptyRule = validation
                                    ? $.grep(validation.rules, function (rule) {
                                        return rule.type === 'empty';
                                    }) !== 0
                                    : false,
                                identifier = validation.identifier || $el.attr('id') || $el.attr('name') || $el.data(metadata.validate)
                            ;
                            if (isRequired && !isDisabled && !hasEmptyRule && identifier !== undefined) {
                                if (isCheckbox) {
                                    module.verbose("Adding 'checked' rule on field", identifier);
                                    module.add.rule(identifier, 'checked');
                                } else {
                                    module.verbose("Adding 'empty' rule on field", identifier);
                                    module.add.rule(identifier, 'empty');
                                }
                            }
                        });
                    },
                    optional: function (identifier, bool) {
                        bool = bool !== false;
                        $.each(validation, function (fieldName, field) {
                            if (identifier === fieldName || identifier === field.identifier) {
                                field.optional = bool;
                            }
                        });
                    },
                },

                validate: {

                    form: function (event, ignoreCallbacks) {
                        var values = module.get.values();

                        // input keydown event will fire submit repeatedly by browser default
                        if (keyHeldDown) {
                            return false;
                        }

                        // reset errors
                        formErrors = [];
                        if (module.determine.isValid()) {
                            module.debug('Form has no validation errors, submitting');
                            module.set.success();
                            if (!settings.inline) {
                                module.remove.errors();
                            }
                            if (ignoreCallbacks !== true) {
                                return settings.onSuccess.call(element, event, values);
                            }
                        } else {
                            module.debug('Form has errors');
                            submitting = false;
                            module.set.error();
                            if (!settings.inline) {
                                module.add.errors(formErrors);
                            }
                            // prevent ajax submit
                            if (event && $module.data('moduleApi') !== undefined) {
                                event.stopImmediatePropagation();
                            }
                            if (settings.errorFocus && ignoreCallbacks !== true) {
                                var
                                    $focusElement,
                                    hasTabIndex = true
                                ;
                                if (typeof settings.errorFocus === 'string') {
                                    $focusElement = $(document).find(settings.errorFocus);
                                    hasTabIndex = $focusElement.is('[tabindex]');
                                    // to be able to focus/scroll into non input elements we need a tabindex
                                    if (!hasTabIndex) {
                                        $focusElement.attr('tabindex', -1);
                                    }
                                } else {
                                    $focusElement = $group.filter('.' + className.error).first().find(selector.field);
                                }
                                $focusElement.trigger('focus');
                                // only remove tabindex if it was dynamically created above
                                if (!hasTabIndex) {
                                    $focusElement.removeAttr('tabindex');
                                }
                            }
                            if (ignoreCallbacks !== true) {
                                return settings.onFailure.call(element, formErrors, values);
                            }
                        }
                    },

                    // takes a validation object and returns whether field passes validation
                    field: function (field, fieldName, showErrors) {
                        showErrors = showErrors !== undefined
                            ? showErrors
                            : true;
                        if (typeof field === 'string') {
                            module.verbose('Validating field', field);
                            fieldName = field;
                            field = validation[field];
                        }
                        if (!field) {
                            module.debug('Unable to find field validation. Skipping', fieldName);

                            return true;
                        }
                        var
                            identifier    = field.identifier || fieldName,
                            $field        = module.get.field(identifier),
                            $dependsField = field.depends
                                ? module.get.field(field.depends)
                                : false,
                            fieldValid  = true,
                            fieldErrors = []
                        ;
                        if (!field.identifier) {
                            module.debug('Using field name as identifier', identifier);
                            field.identifier = identifier;
                        }
                        var isDisabled = $field.filter(':not(:disabled)').length === 0;
                        if (isDisabled) {
                            module.debug('Field is disabled. Skipping', identifier);
                        } else if (field.optional && module.is.blank($field)) {
                            module.debug('Field is optional and blank. Skipping', identifier);
                        } else if (field.depends && module.is.empty($dependsField)) {
                            module.debug('Field depends on another value that is not present or empty. Skipping', $dependsField);
                        } else if (field.rules !== undefined) {
                            if (showErrors) {
                                $field.closest($group).removeClass(className.error);
                            }
                            $.each(field.rules, function (index, rule) {
                                if (module.has.field(identifier)) {
                                    var invalidFields = module.validate.rule(field, rule, true) || [];
                                    if (invalidFields.length > 0) {
                                        module.debug('Field is invalid', identifier, rule.type);
                                        fieldErrors.push(module.get.prompt(rule, field));
                                        fieldValid = false;
                                        if (showErrors) {
                                            $(invalidFields).closest($group).addClass(className.error);
                                        }
                                    }
                                }
                            });
                        }
                        if (fieldValid) {
                            if (showErrors) {
                                module.remove.prompt(identifier, fieldErrors);
                                settings.onValid.call($field);
                            }
                        } else {
                            if (showErrors) {
                                formErrors = formErrors.concat(fieldErrors);
                                module.add.prompt(identifier, fieldErrors, true);
                                settings.onInvalid.call($field, fieldErrors);
                            }

                            return false;
                        }

                        return true;
                    },

                    // takes validation rule and returns whether field passes rule
                    rule: function (field, rule, internal) {
                        var
                            $field       = module.get.field(field.identifier),
                            ancillary    = module.get.ancillaryValue(rule),
                            ruleName     = module.get.ruleName(rule),
                            ruleFunction = settings.rules[ruleName],
                            invalidFields = [],
                            isCheckbox = $field.is(selector.checkbox),
                            isValid = function (field) {
                                var value = isCheckbox ? $(field).filter(':checked').val() : $(field).val();
                                // cast to string avoiding encoding special values
                                value = value === undefined || value === '' || value === null
                                    ? ''
                                    : ((settings.shouldTrim && rule.shouldTrim !== false) || rule.shouldTrim
                                        ? String(value + '').trim()
                                        : String(value + ''));

                                return ruleFunction.call(field, value, ancillary, module);
                            }
                        ;
                        if (!isFunction(ruleFunction)) {
                            module.error(error.noRule, ruleName);

                            return;
                        }
                        if (isCheckbox) {
                            if (!isValid($field)) {
                                invalidFields = $field;
                            }
                        } else {
                            $.each($field, function (index, field) {
                                if (!isValid(field)) {
                                    invalidFields.push(field);
                                }
                            });
                        }

                        return internal ? invalidFields : invalidFields.length === 0;
                    },
                },

                setting: function (name, value) {
                    if ($.isPlainObject(name)) {
                        $.extend(true, settings, name);
                    } else if (value !== undefined) {
                        settings[name] = value;
                    } else {
                        return settings[name];
                    }
                },
                internal: function (name, value) {
                    if ($.isPlainObject(name)) {
                        $.extend(true, module, name);
                    } else if (value !== undefined) {
                        module[name] = value;
                    } else {
                        return module[name];
                    }
                },
                debug: function () {
                    if (!settings.silent && settings.debug) {
                        if (settings.performance) {
                            module.performance.log(arguments);
                        } else {
                            module.debug = Function.prototype.bind.call(console.info, console, settings.name + ':');
                            module.debug.apply(console, arguments);
                        }
                    }
                },
                verbose: function () {
                    if (!settings.silent && settings.verbose && settings.debug) {
                        if (settings.performance) {
                            module.performance.log(arguments);
                        } else {
                            module.verbose = Function.prototype.bind.call(console.info, console, settings.name + ':');
                            module.verbose.apply(console, arguments);
                        }
                    }
                },
                error: function () {
                    if (!settings.silent) {
                        module.error = Function.prototype.bind.call(console.error, console, settings.name + ':');
                        module.error.apply(console, arguments);
                    }
                },
                performance: {
                    log: function (message) {
                        var
                            currentTime,
                            executionTime,
                            previousTime
                        ;
                        if (settings.performance) {
                            currentTime = Date.now();
                            previousTime = time || currentTime;
                            executionTime = currentTime - previousTime;
                            time = currentTime;
                            performance.push({
                                Name: message[0],
                                Arguments: [].slice.call(message, 1) || '',
                                Element: element,
                                'Execution Time': executionTime,
                            });
                        }
                        clearTimeout(module.performance.timer);
                        module.performance.timer = setTimeout(module.performance.display, 500);
                    },
                    display: function () {
                        var
                            title = settings.name + ':',
                            totalTime = 0
                        ;
                        time = false;
                        clearTimeout(module.performance.timer);
                        $.each(performance, function (index, data) {
                            totalTime += data['Execution Time'];
                        });
                        title += ' ' + totalTime + 'ms';
                        if (moduleSelector) {
                            title += ' \'' + moduleSelector + '\'';
                        }
                        if ($allModules.length > 1) {
                            title += ' (' + $allModules.length + ')';
                        }
                        if (performance.length > 0) {
                            console.groupCollapsed(title);
                            if (console.table) {
                                console.table(performance);
                            } else {
                                $.each(performance, function (index, data) {
                                    console.log(data.Name + ': ' + data['Execution Time'] + 'ms');
                                });
                            }
                            console.groupEnd();
                        }
                        performance = [];
                    },
                },
                invoke: function (query, passedArguments, context) {
                    var
                        object = instance,
                        maxDepth,
                        found,
                        response
                    ;
                    passedArguments = passedArguments || queryArguments;
                    context = context || element;
                    if (typeof query === 'string' && object !== undefined) {
                        query = query.split(/[ .]/);
                        maxDepth = query.length - 1;
                        $.each(query, function (depth, value) {
                            var camelCaseValue = depth !== maxDepth
                                ? value + query[depth + 1].charAt(0).toUpperCase() + query[depth + 1].slice(1)
                                : query;
                            if ($.isPlainObject(object[camelCaseValue]) && (depth !== maxDepth)) {
                                object = object[camelCaseValue];
                            } else if (object[camelCaseValue] !== undefined) {
                                found = object[camelCaseValue];

                                return false;
                            } else if ($.isPlainObject(object[value]) && (depth !== maxDepth)) {
                                object = object[value];
                            } else if (object[value] !== undefined) {
                                found = object[value];

                                return false;
                            } else {
                                module.error(error.method, query);

                                return false;
                            }
                        });
                    }
                    if (isFunction(found)) {
                        response = found.apply(context, passedArguments);
                    } else if (found !== undefined) {
                        response = found;
                    }
                    if (Array.isArray(returnedValue)) {
                        returnedValue.push(response);
                    } else if (returnedValue !== undefined) {
                        returnedValue = [returnedValue, response];
                    } else if (response !== undefined) {
                        returnedValue = response;
                    }

                    return found;
                },
            };
            module.initialize();
        });

        return returnedValue !== undefined
            ? returnedValue
            : this;
    };

    $.fn.form.settings = {

        name: 'Form',
        namespace: 'form',

        debug: false,
        verbose: false,
        performance: true,

        fields: false,

        keyboardShortcuts: true,
        on: 'submit',
        inline: false,

        delay: 200,
        revalidate: true,
        shouldTrim: true,

        transition: 'scale',
        duration: 200,

        autoCheckRequired: false,
        preventLeaving: false,
        errorFocus: true,
        dateHandling: 'date', // 'date', 'input', 'formatter'

        onValid: function () {},
        onInvalid: function () {},
        onSuccess: function () {
            return true;
        },
        onFailure: function () {
            return false;
        },
        onDirty: function () {},
        onClean: function () {},

        metadata: {
            defaultValue: 'default',
            validate: 'validate',
            isDirty: 'isDirty',
        },

        regExp: {
            htmlID: /^[A-Za-z][\w.:-]*$/g,
            bracket: /\[(.*)]/i,
            decimal: /^\d+\.?\d*$/,
            email: /^[\w!#$%&'*+./=?^`{|}~-]+@[\da-z]([\da-z-]*[\da-z])?(\.[\da-z]([\da-z-]*[\da-z])?)*$/i,
            escape: /[$()*+,./:=?@[\\\]^{|}-]/g,
            flags: /^\/(.*)\/(.*)?/,
            integer: /^-?\d+$/,
            number: /^-?\d*(\.\d+)?$/,
            url: /(https?:\/\/(?:www\.|(?!www))[^\s.]+\.\S{2,}|www\.\S+\.\S{2,})/i,
        },

        text: {
            and: 'and',
            unspecifiedRule: 'Please enter a valid value',
            unspecifiedField: 'This field',
            leavingMessage: 'There are unsaved changes on this page which will be discarded if you continue.',
        },

        prompt: {
            range: '{name} must be in a range from {min} to {max}',
            maxValue: '{name} must have a maximum value of {ruleValue}',
            minValue: '{name} must have a minimum value of {ruleValue}',
            empty: '{name} must have a value',
            checked: '{name} must be checked',
            email: '{name} must be a valid e-mail',
            url: '{name} must be a valid url',
            regExp: '{name} is not formatted correctly',
            integer: '{name} must be an integer',
            decimal: '{name} must be a decimal number',
            number: '{name} must be set to a number',
            is: '{name} must be "{ruleValue}"',
            isExactly: '{name} must be exactly "{ruleValue}"',
            not: '{name} cannot be set to "{ruleValue}"',
            notExactly: '{name} cannot be set to exactly "{ruleValue}"',
            contain: '{name} must contain "{ruleValue}"',
            containExactly: '{name} must contain exactly "{ruleValue}"',
            doesntContain: '{name} cannot contain "{ruleValue}"',
            doesntContainExactly: '{name} cannot contain exactly "{ruleValue}"',
            minLength: '{name} must be at least {ruleValue} characters',
            exactLength: '{name} must be exactly {ruleValue} characters',
            maxLength: '{name} cannot be longer than {ruleValue} characters',
            size: '{name} must have a length between {min} and {max} characters',
            match: '{name} must match {ruleValue} field',
            different: '{name} must have a different value than {ruleValue} field',
            creditCard: '{name} must be a valid credit card number',
            minCount: '{name} must have at least {ruleValue} choices',
            exactCount: '{name} must have exactly {ruleValue} choices',
            maxCount: '{name} must have {ruleValue} or less choices',
            addErrors: '{name}: {error}',
        },

        selector: {
            checkbox: 'input[type="checkbox"], input[type="radio"]',
            clear: '.clear',
            field: 'input:not(.search):not([type="file"]):not([type="reset"]):not([type="button"]):not([type="submit"]), textarea, select',
            group: '.field',
            input: 'input:not([type="file"])',
            message: '.error.message',
            prompt: '.prompt.label',
            radio: 'input[type="radio"]',
            reset: '.reset:not([type="reset"])',
            submit: '.submit:not([type="submit"])',
            uiCheckbox: '.ui.checkbox',
            uiDropdown: '.ui.dropdown',
            uiCalendar: '.ui.calendar',
        },

        className: {
            error: 'error',
            label: 'ui basic red pointing prompt label',
            pressed: 'down',
            success: 'success',
            required: 'required',
            disabled: 'disabled',
        },

        error: {
            method: 'The method you called is not defined.',
            noRule: 'There is no rule matching the one you specified',
            noField: 'Field identifier {identifier} not found',
            noElement: 'This module requires ui {element}',
            noErrorMessage: 'No error message provided',
        },

        templates: {

            // template that produces error message
            error: function (errors) {
                var
                    html = '<ul class="list">'
                ;
                $.each(errors, function (index, value) {
                    html += '<li>' + value + '</li>';
                });
                html += '</ul>';

                return html;
            },

            // template that produces label content
            prompt: function (errors) {
                if (errors.length === 1) {
                    return errors[0];
                }
                var
                    html = '<ul class="ui list">'
                ;
                $.each(errors, function (index, value) {
                    html += '<li>' + value + '</li>';
                });
                html += '</ul>';

                return html;
            },
        },

        formatter: {
            date: function (date) {
                return Intl.DateTimeFormat('en-GB').format(date);
            },
            datetime: function (date) {
                return Intl.DateTimeFormat('en-GB', {
                    year: 'numeric',
                    month: '2-digit',
                    day: '2-digit',
                    hour: '2-digit',
                    minute: '2-digit',
                    second: '2-digit',
                }).format(date);
            },
            time: function (date) {
                return Intl.DateTimeFormat('en-GB', {
                    hour: '2-digit',
                    minute: '2-digit',
                    second: '2-digit',
                }).format(date);
            },
            month: function (date) {
                return Intl.DateTimeFormat('en-GB', {
                    month: '2-digit',
                    year: 'numeric',
                }).format(date);
            },
            year: function (date) {
                return Intl.DateTimeFormat('en-GB', {
                    year: 'numeric',
                }).format(date);
            },
        },

        rules: {

            // is not empty or blank string
            empty: function (value) {
                return !(value === undefined || value === '' || (Array.isArray(value) && value.length === 0));
            },

            // checkbox checked
            checked: function () {
                return $(this).filter(':checked').length > 0;
            },

            // is most likely an email
            email: function (value) {
                return $.fn.form.settings.regExp.email.test(value);
            },

            // value is most likely url
            url: function (value) {
                return $.fn.form.settings.regExp.url.test(value);
            },

            // matches specified regExp
            regExp: function (value, regExp) {
                if (regExp instanceof RegExp) {
                    return value.match(regExp);
                }
                var
                    regExpParts = regExp.match($.fn.form.settings.regExp.flags),
                    flags
                ;
                // regular expression specified as /baz/gi (flags)
                if (regExpParts) {
                    regExp = regExpParts.length >= 2
                        ? regExpParts[1]
                        : regExp;
                    flags = regExpParts.length >= 3
                        ? regExpParts[2]
                        : '';
                }

                return value.match(new RegExp(regExp, flags));
            },
            minValue: function (value, range) {
                return $.fn.form.settings.rules.range(value, range + '..', 'number');
            },
            maxValue: function (value, range) {
                return $.fn.form.settings.rules.range(value, '..' + range, 'number');
            },
            // is valid integer or matches range
            integer: function (value, range) {
                return $.fn.form.settings.rules.range(value, range, 'integer');
            },
            range: function (value, range, regExp, testLength) {
                if (typeof regExp === 'string') {
                    regExp = $.fn.form.settings.regExp[regExp];
                }
                if (!(regExp instanceof RegExp)) {
                    regExp = $.fn.form.settings.regExp.integer;
                }
                var
                    min,
                    max,
                    parts
                ;
                if (!range || ['', '..'].indexOf(range) !== -1) {

                    // do nothing
                } else if (range.indexOf('..') === -1) {
                    if (regExp.test(range)) {
                        min = range - 0;
                        max = min;
                    }
                } else {
                    parts = range.split('..', 2);
                    if (regExp.test(parts[0])) {
                        min = parts[0] - 0;
                    }
                    if (regExp.test(parts[1])) {
                        max = parts[1] - 0;
                    }
                }
                if (testLength) {
                    value = value.length;
                }

                return (
                    regExp.test(value)
                        && (min === undefined || value >= min)
                        && (max === undefined || value <= max)
                );
            },

            // is valid number (with decimal)
            decimal: function (value, range) {
                return $.fn.form.settings.rules.range(value, range, 'decimal');
            },

            // is valid number
            number: function (value, range) {
                return $.fn.form.settings.rules.range(value, range, 'number');
            },

            // is value (case insensitive)
            is: function (value, text) {
                text = typeof text === 'string'
                    ? text.toLowerCase()
                    : text;
                value = typeof value === 'string'
                    ? value.toLowerCase()
                    : value;

                return value == text;
            },

            // is value
            isExactly: function (value, text) {
                return value == text;
            },

            // value is not another value (case insensitive)
            not: function (value, notValue) {
                value = typeof value === 'string'
                    ? value.toLowerCase()
                    : value;
                notValue = typeof notValue === 'string'
                    ? notValue.toLowerCase()
                    : notValue;

                return value != notValue;
            },

            // value is not another value (case sensitive)
            notExactly: function (value, notValue) {
                return value != notValue;
            },

            // value contains text (insensitive)
            contains: function (value, text) {
                // escape regex characters
                text = text.replace($.fn.form.settings.regExp.escape, '\\$&');

                return value.search(new RegExp(text, 'i')) !== -1;
            },

            // value contains text (case sensitive)
            containsExactly: function (value, text) {
                // escape regex characters
                text = text.replace($.fn.form.settings.regExp.escape, '\\$&');

                return value.search(new RegExp(text)) !== -1;
            },

            // value contains text (insensitive)
            doesntContain: function (value, text) {
                // escape regex characters
                text = text.replace($.fn.form.settings.regExp.escape, '\\$&');

                return value.search(new RegExp(text, 'i')) === -1;
            },

            // value contains text (case sensitive)
            doesntContainExactly: function (value, text) {
                // escape regex characters
                text = text.replace($.fn.form.settings.regExp.escape, '\\$&');

                return value.search(new RegExp(text)) === -1;
            },

            // is at least string length
            minLength: function (value, minLength) {
                return $.fn.form.settings.rules.range(value, minLength + '..', 'integer', true);
            },

            // is exactly length
            exactLength: function (value, requiredLength) {
                return $.fn.form.settings.rules.range(value, requiredLength + '..' + requiredLength, 'integer', true);
            },

            // is less than length
            maxLength: function (value, maxLength) {
                return $.fn.form.settings.rules.range(value, '..' + maxLength, 'integer', true);
            },

            size: function (value, range) {
                return $.fn.form.settings.rules.range(value, range, 'integer', true);
            },

            // matches another field
            match: function (value, identifier, module) {
                var matchingValue = module.get.value(identifier, true);

                return matchingValue !== undefined
                    ? value.toString() === matchingValue.toString()
                    : false;
            },

            // different than another field
            different: function (value, identifier, module) {
                var matchingValue = module.get.value(identifier, true);

                return matchingValue !== undefined
                    ? value.toString() !== matchingValue.toString()
                    : false;
            },

            creditCard: function (cardNumber, cardTypes) {
                var
                    cards = {
                        visa: {
                            pattern: /^4/,
                            length: [16],
                        },
                        amex: {
                            pattern: /^3[47]/,
                            length: [15],
                        },
                        mastercard: {
                            pattern: /^5[1-5]/,
                            length: [16],
                        },
                        discover: {
                            pattern: /^(6011|622(12[6-9]|1[3-9]\d|[2-8]\d{2}|9[01]\d|92[0-5]|64[4-9])|65)/,
                            length: [16],
                        },
                        unionPay: {
                            pattern: /^(62|88)/,
                            length: [16, 17, 18, 19],
                        },
                        jcb: {
                            pattern: /^35(2[89]|[3-8]\d)/,
                            length: [16],
                        },
                        maestro: {
                            pattern: /^(5018|5020|5038|6304|6759|676[1-3])/,
                            length: [12, 13, 14, 15, 16, 17, 18, 19],
                        },
                        dinersClub: {
                            pattern: /^(30[0-5]|^36)/,
                            length: [14],
                        },
                        laser: {
                            pattern: /^(6304|670[69]|6771)/,
                            length: [16, 17, 18, 19],
                        },
                        visaElectron: {
                            pattern: /^(4026|417500|4508|4844|491(3|7))/,
                            length: [16],
                        },
                    },
                    valid         = {},
                    validCard     = false,
                    requiredTypes = typeof cardTypes === 'string'
                        ? cardTypes.split(',')
                        : false,
                    unionPay,
                    validation
                ;

                if (typeof cardNumber !== 'string' || cardNumber.length === 0) {
                    return;
                }

                // allow dashes and spaces in card
                cardNumber = cardNumber.replace(/[\s-]/g, '');

                // verify card types
                if (requiredTypes) {
                    $.each(requiredTypes, function (index, type) {
                        // verify each card type
                        validation = cards[type];
                        if (validation) {
                            valid = {
                                length: $.inArray(cardNumber.length, validation.length) !== -1,
                                pattern: cardNumber.search(validation.pattern) !== -1,
                            };
                            if (valid.length > 0 && valid.pattern) {
                                validCard = true;
                            }
                        }
                    });

                    if (!validCard) {
                        return false;
                    }
                }

                // skip luhn for UnionPay
                unionPay = {
                    number: $.inArray(cardNumber.length, cards.unionPay.length) !== -1,
                    pattern: cardNumber.search(cards.unionPay.pattern) !== -1,
                };
                if (unionPay.number && unionPay.pattern) {
                    return true;
                }

                // verify luhn, adapted from  <https://gist.github.com/2134376>
                var
                    length        = cardNumber.length,
                    multiple      = 0,
                    producedValue = [
                        [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
                        [0, 2, 4, 6, 8, 1, 3, 5, 7, 9],
                    ],
                    sum           = 0
                ;
                while (length--) {
                    sum += producedValue[multiple][parseInt(cardNumber.charAt(length), 10)];
                    multiple ^= 1; // eslint-disable-line no-bitwise
                }

                return sum % 10 === 0 && sum > 0;
            },

            minCount: function (value, minCount) {
                minCount = Number(minCount);

                if (minCount === 0) {
                    return true;
                }
                if (minCount === 1) {
                    return value !== '';
                }

                return value.split(',').length >= minCount;
            },

            exactCount: function (value, exactCount) {
                exactCount = Number(exactCount);

                if (exactCount === 0) {
                    return value === '';
                }
                if (exactCount === 1) {
                    return value !== '' && value.search(',') === -1;
                }

                return value.split(',').length === exactCount;
            },

            maxCount: function (value, maxCount) {
                maxCount = Number(maxCount);

                if (maxCount === 0) {
                    return false;
                }
                if (maxCount === 1) {
                    return value.search(',') === -1;
                }

                return value.split(',').length <= maxCount;
            },
        },

    };
})(jQuery, window, document);