Use custom templatetags instead settings custom attributes to Boundfields

As it do not work with django 1.7

cas_server/forms.py

@@ -26,15 +26,11 @@ class BootsrapForm(forms.Form):
     """
     def __init__(self, *args, **kwargs):
         super(BootsrapForm, self).__init__(*args, **kwargs)
-        for (name, field) in self.fields.items():
+        for field in self.fields.values():
             # Only tweak the fiel if it will be displayed
             if not isinstance(field.widget, forms.HiddenInput):
-                # tell to display the field (used in form.html)
-                self[name].display = True
                 attrs = {}
-                if isinstance(field.widget, forms.CheckboxInput):
-                    self[name].checkbox = True
-                else:
+                if not isinstance(field.widget, forms.CheckboxInput):
                     attrs['class'] = "form-control"
                     if field.label:  # pragma: no branch (currently all field are hidden or labeled)
                         attrs["placeholder"] = field.label

cas_server/templates/cas_server/form.html

@@ -1,10 +1,11 @@
+{% load cas_server %}
 {% for error in form.non_field_errors %}
 <div class="alert alert-danger alert-dismissable">
   <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&#215;</button>
   {{error}}
 </div>
 {% endfor %}
-{% for field in form %}{% if field.display %}
+{% for field in form %}{% if not field|is_hidden %}
 <div class="form-group{% spaceless %}
   {% if not form.non_field_errors %}
     {% if field.errors %} has-error
@@ -12,7 +13,7 @@
     {% endif %}
   {% endif %}"
 {% endspaceless %}>{% spaceless %}
-  {% if field.checkbox %}
+  {% if field|is_checkbox %}
     <div class="checkbox"><label for="{{field.auto_id}}">{{field}}{{field.label}}</label>
   {% else %}
     <label class="control-label" for="{{field.auto_id}}">{{field.label}}</label>

cas_server/templatetags/cas_server.py

@@ -0,0 +1,14 @@
+from django import template
+from django import forms
+
+register = template.Library()
+
+
+@register.filter(name='is_checkbox')
+def is_checkbox(field):
+    return isinstance(field.field.widget, forms.CheckboxInput)
+
+
+@register.filter(name='is_hidden')
+def is_hidden(field):
+    return isinstance(field.field.widget, forms.HiddenInput)