wed
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Wed is a schema-aware editor for XML documents.
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JavaScript
define(function(require,exports,module){
import { Observable } from '../Observable';
import { isArray } from '../util/isArray';
import { isFunction } from '../util/isFunction';
import { map } from '../operators/map';
/* tslint:enable:max-line-length */
/**
* 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. 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 = 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, signal?: any): void} [removeHandler] An optional function that
* takes a `handler` function as argument and removes it in case it was
* previously attached using `addHandler`. if addHandler returns signal to teardown when remove,
* removeHandler function will forward it.
* @return {Observable<T>}
* @name fromEventPattern
*/
export function fromEventPattern(addHandler, removeHandler, resultSelector) {
if (resultSelector) {
// DEPRECATED PATH
return fromEventPattern(addHandler, removeHandler).pipe(map(args => isArray(args) ? resultSelector(...args) : resultSelector(args)));
}
return new Observable(subscriber => {
const handler = (...e) => subscriber.next(e.length === 1 ? e[0] : e);
let retValue;
try {
retValue = addHandler(handler);
}
catch (err) {
subscriber.error(err);
return undefined;
}
if (!isFunction(removeHandler)) {
return undefined;
}
return () => removeHandler(handler, retValue);
});
}
//# sourceMappingURL=fromEventPattern.js.map
return module.exports;
});