@reactivex/rxjs
Version:
Reactive Extensions for modern JavaScript
97 lines • 4.45 kB
JavaScript
var __extends = (this && this.__extends) || function (d, b) {
for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
define(["require", "exports", '../Observable', '../Subscription', '../util/tryCatch', '../util/errorObject'], function (require, exports, Observable_1, Subscription_1, tryCatch_1, errorObject_1) {
"use strict";
/**
* We need this JSDoc comment for affecting ESDoc.
* @extends {Ignored}
* @hide true
*/
var FromEventPatternObservable = (function (_super) {
__extends(FromEventPatternObservable, _super);
function FromEventPatternObservable(addHandler, removeHandler, selector) {
_super.call(this);
this.addHandler = addHandler;
this.removeHandler = removeHandler;
this.selector = selector;
}
/**
* Creates an Observable from an API based on addHandler/removeHandler
* functions.
*
* <span class="informal">Converts any addHandler/removeHandler API to an
* Observable.</span>
*
* <img src="./img/fromEventPattern.png" width="100%">
*
* Creates an Observable by using the `addHandler` and `removeHandler`
* functions to add and remove the handlers, with an optional selector
* function to project the event arguments to a result. The `addHandler` is
* called when the output Observable is subscribed, and `removeHandler` is
* called when the Subscription is unsubscribed.
*
* @example <caption>Emits clicks happening on the DOM document</caption>
* function addClickHandler(handler) {
* document.addEventListener('click', handler);
* }
*
* function removeClickHandler(handler) {
* document.removeEventListener('click', handler);
* }
*
* var clicks = Rx.Observable.fromEventPattern(
* addClickHandler,
* removeClickHandler
* );
* clicks.subscribe(x => console.log(x));
*
* @see {@link from}
* @see {@link fromEvent}
*
* @param {function(handler: Function): any} addHandler A function that takes
* a `handler` function as argument and attaches it somehow to the actual
* source of events.
* @param {function(handler: Function): void} removeHandler A function that
* takes a `handler` function as argument and removes it in case it was
* previously attached using `addHandler`.
* @param {function(...args: any): T} [selector] An optional function to
* post-process results. It takes the arguments from the event handler and
* should return a single value.
* @return {Observable<T>}
* @static true
* @name fromEventPattern
* @owner Observable
*/
FromEventPatternObservable.create = function (addHandler, removeHandler, selector) {
return new FromEventPatternObservable(addHandler, removeHandler, selector);
};
FromEventPatternObservable.prototype._subscribe = function (subscriber) {
var addHandler = this.addHandler;
var removeHandler = this.removeHandler;
var selector = this.selector;
var handler = selector ? function (e) {
var result = tryCatch_1.tryCatch(selector).apply(null, arguments);
if (result === errorObject_1.errorObject) {
subscriber.error(result.e);
}
else {
subscriber.next(result);
}
} : function (e) { subscriber.next(e); };
var result = tryCatch_1.tryCatch(addHandler)(handler);
if (result === errorObject_1.errorObject) {
subscriber.error(result.e);
}
subscriber.add(new Subscription_1.Subscription(function () {
//TODO: determine whether or not to forward to error handler
removeHandler(handler);
}));
};
return FromEventPatternObservable;
}(Observable_1.Observable));
exports.FromEventPatternObservable = FromEventPatternObservable;
});
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