"use strict"; 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 __()); }; var Observable_1 = require('../Observable'); var tryCatch_1 = require('../util/tryCatch'); var errorObject_1 = require('../util/errorObject'); var AsyncSubject_1 = require('../AsyncSubject'); /** * We need this JSDoc comment for affecting ESDoc. * @extends {Ignored} * @hide true */ var BoundCallbackObservable = (function (_super) { __extends(BoundCallbackObservable, _super); function BoundCallbackObservable(callbackFunc, selector, args, context, scheduler) { _super.call(this); this.callbackFunc = callbackFunc; this.selector = selector; this.args = args; this.context = context; this.scheduler = scheduler; } /* tslint:enable:max-line-length */ /** * Converts a callback API to a function that returns an Observable. * * Give it a function `f` of type `f(x, callback)` and * it will return a function `g` that when called as `g(x)` will output an * Observable. * * `bindCallback` is not an operator because its input and output are not * Observables. The input is a function `func` with some parameters, the * last parameter must be a callback function that `func` calls when it is * done. * * The output of `bindCallback` is a function that takes the same parameters * as `func`, except the last one (the callback). When the output function * is called with arguments it will return an Observable. If function `func` * calls its callback with one argument the Observable will emit that value. * If on the other hand the callback is called with multiple values the resulting * Observable will emit an array with said values as arguments. * * It is very important to remember that input function `func` is not called * when the output function is, but rather when the Observable returned by the output * function is subscribed. This means if `func` makes an AJAX request, that request * will be made every time someone subscribes to the resulting Observable, but not before. * * Optionally, a selector function can be passed to `bindObservable`. The selector function * takes the same arguments as the callback and returns the value that will be emitted by the Observable. * Even though by default multiple arguments passed to callback appear in the stream as an array * the selector function will be called with arguments directly, just as the callback would. * This means you can imagine the default selector (when one is not provided explicitly) * as a function that aggregates all its arguments into an array, or simply returns first argument * if there is only one. * * The last optional parameter - {@link Scheduler} - can be used to control when the call * to `func` happens after someone subscribes to Observable, as well as when results * passed to callback will be emitted. By default, the subscription to an Observable calls `func` * synchronously, but using `Scheduler.async` as the last parameter will defer the call to `func`, * just like wrapping the call in `setTimeout` with a timeout of `0` would. If you use the async Scheduler * and call `subscribe` on the output Observable all function calls that are currently executing * will end before `func` is invoked. * * By default results passed to the callback are emitted immediately after `func` invokes the callback. * In particular, if the callback is called synchronously the subscription of the resulting Observable * will call the `next` function synchronously as well. If you want to defer that call, * you may use `Scheduler.async` just as before. This means that by using `Scheduler.async` you can * ensure that `func` always calls its callback asynchronously, thus avoiding terrifying Zalgo. * * Note that the Observable created by the output function will always emit a single value * and then complete immediately. If `func` calls the callback multiple times, values from subsequent * calls will not appear in the stream. If you need to listen for multiple calls, * you probably want to use {@link fromEvent} or {@link fromEventPattern} instead. * * If `func` depends on some context (`this` property) and is not already bound the context of `func` * will be the context that the output function has at call time. In particular, if `func` * is called as a method of some objec and if `func` is not already bound, in order to preserve the context * it is recommended that the context of the output function is set to that object as well. * * If the input function calls its callback in the "node style" (i.e. first argument to callback is * optional error parameter signaling whether the call failed or not), {@link bindNodeCallback} * provides convenient error handling and probably is a better choice. * `bindCallback` will treat such functions the same as any other and error parameters * (whether passed or not) will always be interpreted as regular callback argument. * * * @example Convert jQuery's getJSON to an Observable API * // Suppose we have jQuery.getJSON('/my/url', callback) * var getJSONAsObservable = Rx.Observable.bindCallback(jQuery.getJSON); * var result = getJSONAsObservable('/my/url'); * result.subscribe(x => console.log(x), e => console.error(e)); * * * @example Receive an array of arguments passed to a callback * someFunction((a, b, c) => { * console.log(a); // 5 * console.log(b); // 'some string' * console.log(c); // {someProperty: 'someValue'} * }); * * const boundSomeFunction = Rx.Observable.bindCallback(someFunction); * boundSomeFunction().subscribe(values => { * console.log(values) // [5, 'some string', {someProperty: 'someValue'}] * }); * * * @example Use bindCallback with a selector function * someFunction((a, b, c) => { * console.log(a); // 'a' * console.log(b); // 'b' * console.log(c); // 'c' * }); * * const boundSomeFunction = Rx.Observable.bindCallback(someFunction, (a, b, c) => a + b + c); * boundSomeFunction().subscribe(value => { * console.log(value) // 'abc' * }); * * * @example Compare behaviour with and without async Scheduler * function iCallMyCallbackSynchronously(cb) { * cb(); * } * * const boundSyncFn = Rx.Observable.bindCallback(iCallMyCallbackSynchronously); * const boundAsyncFn = Rx.Observable.bindCallback(iCallMyCallbackSynchronously, null, Rx.Scheduler.async); * * boundSyncFn().subscribe(() => console.log('I was sync!')); * boundAsyncFn().subscribe(() => console.log('I was async!')); * console.log('This happened...'); * * // Logs: * // I was sync! * // This happened... * // I was async! * * * @example Use bindCallback on an object method * const boundMethod = Rx.Observable.bindCallback(someObject.methodWithCallback); * boundMethod.call(someObject) // make sure methodWithCallback has access to someObject * .subscribe(subscriber); * * * @see {@link bindNodeCallback} * @see {@link from} * @see {@link fromPromise} * * @param {function} func A function with a callback as the last parameter. * @param {function} [selector] A function which takes the arguments from the * callback and maps them to a value that is emitted on the output Observable. * @param {Scheduler} [scheduler] The scheduler on which to schedule the * callbacks. * @return {function(...params: *): Observable} A function which returns the * Observable that delivers the same values the callback would deliver. * @static true * @name bindCallback * @owner Observable */ BoundCallbackObservable.create = function (func, selector, scheduler) { if (selector === void 0) { selector = undefined; } return function () { var args = []; for (var _i = 0; _i < arguments.length; _i++) { args[_i - 0] = arguments[_i]; } return new BoundCallbackObservable(func, selector, args, this, scheduler); }; }; /** @deprecated internal use only */ BoundCallbackObservable.prototype._subscribe = function (subscriber) { var callbackFunc = this.callbackFunc; var args = this.args; var scheduler = this.scheduler; var subject = this.subject; if (!scheduler) { if (!subject) { subject = this.subject = new AsyncSubject_1.AsyncSubject(); var handler = function handlerFn() { var innerArgs = []; for (var _i = 0; _i < arguments.length; _i++) { innerArgs[_i - 0] = arguments[_i]; } var source = handlerFn.source; var selector = source.selector, subject = source.subject; if (selector) { var result_1 = tryCatch_1.tryCatch(selector).apply(this, innerArgs); if (result_1 === errorObject_1.errorObject) { subject.error(errorObject_1.errorObject.e); } else { subject.next(result_1); subject.complete(); } } else { subject.next(innerArgs.length <= 1 ? innerArgs[0] : innerArgs); subject.complete(); } }; // use named function instance to avoid closure. handler.source = this; var result = tryCatch_1.tryCatch(callbackFunc).apply(this.context, args.concat(handler)); if (result === errorObject_1.errorObject) { subject.error(errorObject_1.errorObject.e); } } return subject.subscribe(subscriber); } else { return scheduler.schedule(BoundCallbackObservable.dispatch, 0, { source: this, subscriber: subscriber, context: this.context }); } }; BoundCallbackObservable.dispatch = function (state) { var self = this; var source = state.source, subscriber = state.subscriber, context = state.context; var callbackFunc = source.callbackFunc, args = source.args, scheduler = source.scheduler; var subject = source.subject; if (!subject) { subject = source.subject = new AsyncSubject_1.AsyncSubject(); var handler = function handlerFn() { var innerArgs = []; for (var _i = 0; _i < arguments.length; _i++) { innerArgs[_i - 0] = arguments[_i]; } var source = handlerFn.source; var selector = source.selector, subject = source.subject; if (selector) { var result_2 = tryCatch_1.tryCatch(selector).apply(this, innerArgs); if (result_2 === errorObject_1.errorObject) { self.add(scheduler.schedule(dispatchError, 0, { err: errorObject_1.errorObject.e, subject: subject })); } else { self.add(scheduler.schedule(dispatchNext, 0, { value: result_2, subject: subject })); } } else { var value = innerArgs.length <= 1 ? innerArgs[0] : innerArgs; self.add(scheduler.schedule(dispatchNext, 0, { value: value, subject: subject })); } }; // use named function to pass values in without closure handler.source = source; var result = tryCatch_1.tryCatch(callbackFunc).apply(context, args.concat(handler)); if (result === errorObject_1.errorObject) { subject.error(errorObject_1.errorObject.e); } } self.add(subject.subscribe(subscriber)); }; return BoundCallbackObservable; }(Observable_1.Observable)); exports.BoundCallbackObservable = BoundCallbackObservable; function dispatchNext(arg) { var value = arg.value, subject = arg.subject; subject.next(value); subject.complete(); } function dispatchError(arg) { var err = arg.err, subject = arg.subject; subject.error(err); } //# sourceMappingURL=BoundCallbackObservable.js.map