work.suroh.tk/node_modules/rxjs/operator/find.js

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2019-12-02 12:22:45 +00:00
"use strict";
var find_1 = require('../operators/find');
/* tslint:enable:max-line-length */
/**
* Emits only the first value emitted by the source Observable that meets some
* condition.
*
* <span class="informal">Finds the first value that passes some test and emits
* that.</span>
*
* <img src="./img/find.png" width="100%">
*
* `find` searches for the first item in the source Observable that matches the
* specified condition embodied by the `predicate`, and returns the first
* occurrence in the source. Unlike {@link first}, the `predicate` is required
* in `find`, and does not emit an error if a valid value is not found.
*
* @example <caption>Find and emit the first click that happens on a DIV element</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var result = clicks.find(ev => ev.target.tagName === 'DIV');
* result.subscribe(x => console.log(x));
*
* @see {@link filter}
* @see {@link first}
* @see {@link findIndex}
* @see {@link take}
*
* @param {function(value: T, index: number, source: Observable<T>): boolean} predicate
* A function called with each item to test for condition matching.
* @param {any} [thisArg] An optional argument to determine the value of `this`
* in the `predicate` function.
* @return {Observable<T>} An Observable of the first item that matches the
* condition.
* @method find
* @owner Observable
*/
function find(predicate, thisArg) {
return find_1.find(predicate, thisArg)(this);
}
exports.find = find;
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