wishthis/node_modules/rxjs/_esm2015/internal/observable/fromEvent.js
2022-01-21 09:28:41 +01:00

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2.4 KiB
JavaScript

import { Observable } from '../Observable';
import { isArray } from '../util/isArray';
import { isFunction } from '../util/isFunction';
import { map } from '../operators/map';
const toString = (() => Object.prototype.toString)();
export function fromEvent(target, eventName, options, resultSelector) {
if (isFunction(options)) {
resultSelector = options;
options = undefined;
}
if (resultSelector) {
return fromEvent(target, eventName, options).pipe(map(args => isArray(args) ? resultSelector(...args) : resultSelector(args)));
}
return new Observable(subscriber => {
function handler(e) {
if (arguments.length > 1) {
subscriber.next(Array.prototype.slice.call(arguments));
}
else {
subscriber.next(e);
}
}
setupSubscription(target, eventName, handler, subscriber, options);
});
}
function setupSubscription(sourceObj, eventName, handler, subscriber, options) {
let unsubscribe;
if (isEventTarget(sourceObj)) {
const source = sourceObj;
sourceObj.addEventListener(eventName, handler, options);
unsubscribe = () => source.removeEventListener(eventName, handler, options);
}
else if (isJQueryStyleEventEmitter(sourceObj)) {
const source = sourceObj;
sourceObj.on(eventName, handler);
unsubscribe = () => source.off(eventName, handler);
}
else if (isNodeStyleEventEmitter(sourceObj)) {
const source = sourceObj;
sourceObj.addListener(eventName, handler);
unsubscribe = () => source.removeListener(eventName, handler);
}
else if (sourceObj && sourceObj.length) {
for (let i = 0, len = sourceObj.length; i < len; i++) {
setupSubscription(sourceObj[i], eventName, handler, subscriber, options);
}
}
else {
throw new TypeError('Invalid event target');
}
subscriber.add(unsubscribe);
}
function isNodeStyleEventEmitter(sourceObj) {
return sourceObj && typeof sourceObj.addListener === 'function' && typeof sourceObj.removeListener === 'function';
}
function isJQueryStyleEventEmitter(sourceObj) {
return sourceObj && typeof sourceObj.on === 'function' && typeof sourceObj.off === 'function';
}
function isEventTarget(sourceObj) {
return sourceObj && typeof sourceObj.addEventListener === 'function' && typeof sourceObj.removeEventListener === 'function';
}
//# sourceMappingURL=fromEvent.js.map