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- "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 BoundNodeCallbackObservable = (function (_super) {
- __extends(BoundNodeCallbackObservable, _super);
- function BoundNodeCallbackObservable(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 Node.js-style callback API to a function that returns an
- * Observable.
- *
- * <span class="informal">It's just like {@link bindCallback}, but the
- * callback is expected to be of type `callback(error, result)`.</span>
- *
- * `bindNodeCallback` is not an operator because its input and output are not
- * Observables. The input is a function `func` with some parameters, but the
- * last parameter must be a callback function that `func` calls when it is
- * done. The callback function is expected to follow Node.js conventions,
- * where the first argument to the callback is an error object, signaling
- * whether call was successful. If that object is passed to callback, it means
- * something went wrong.
- *
- * The output of `bindNodeCallback` 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 `func` calls its callback with error parameter present, Observable will
- * error with that value as well. If error parameter is not passed, Observable will emit
- * second parameter. If there are more parameters (third and so on),
- * Observable will emit an array with all arguments, except first error argument.
- *
- * Optionally `bindNodeCallback` accepts selector function, which allows you to
- * make resulting Observable emit value computed by selector, instead of regular
- * callback arguments. It works similarly to {@link bindCallback} selector, but
- * Node.js-style error argument will never be passed to that function.
- *
- * Note that `func` will not be called at the same time output function is,
- * but rather whenever resulting Observable is subscribed. By default call to
- * `func` will happen synchronously after subscription, but that can be changed
- * with proper {@link Scheduler} provided as optional third parameter. Scheduler
- * can also control when values from callback will be emitted by Observable.
- * To find out more, check out documentation for {@link bindCallback}, where
- * Scheduler works exactly the same.
- *
- * As in {@link bindCallback}, context (`this` property) of input function will be set to context
- * of returned function, when it is called.
- *
- * After Observable emits value, it will complete immediately. This means
- * even if `func` calls callback again, values from second and consecutive
- * calls will never appear on the stream. If you need to handle functions
- * that call callbacks multiple times, check out {@link fromEvent} or
- * {@link fromEventPattern} instead.
- *
- * Note that `bindNodeCallback` can be used in non-Node.js environments as well.
- * "Node.js-style" callbacks are just a convention, so if you write for
- * browsers or any other environment and API you use implements that callback style,
- * `bindNodeCallback` can be safely used on that API functions as well.
- *
- * Remember that Error object passed to callback does not have to be an instance
- * of JavaScript built-in `Error` object. In fact, it does not even have to an object.
- * Error parameter of callback function is interpreted as "present", when value
- * of that parameter is truthy. It could be, for example, non-zero number, non-empty
- * string or boolean `true`. In all of these cases resulting Observable would error
- * with that value. This means usually regular style callbacks will fail very often when
- * `bindNodeCallback` is used. If your Observable errors much more often then you
- * would expect, check if callback really is called in Node.js-style and, if not,
- * switch to {@link bindCallback} instead.
- *
- * Note that even if error parameter is technically present in callback, but its value
- * is falsy, it still won't appear in array emitted by Observable or in selector function.
- *
- *
- * @example <caption>Read a file from the filesystem and get the data as an Observable</caption>
- * import * as fs from 'fs';
- * var readFileAsObservable = Rx.Observable.bindNodeCallback(fs.readFile);
- * var result = readFileAsObservable('./roadNames.txt', 'utf8');
- * result.subscribe(x => console.log(x), e => console.error(e));
- *
- *
- * @example <caption>Use on function calling callback with multiple arguments</caption>
- * someFunction((err, a, b) => {
- * console.log(err); // null
- * console.log(a); // 5
- * console.log(b); // "some string"
- * });
- * var boundSomeFunction = Rx.Observable.bindNodeCallback(someFunction);
- * boundSomeFunction()
- * .subscribe(value => {
- * console.log(value); // [5, "some string"]
- * });
- *
- *
- * @example <caption>Use with selector function</caption>
- * someFunction((err, a, b) => {
- * console.log(err); // undefined
- * console.log(a); // "abc"
- * console.log(b); // "DEF"
- * });
- * var boundSomeFunction = Rx.Observable.bindNodeCallback(someFunction, (a, b) => a + b);
- * boundSomeFunction()
- * .subscribe(value => {
- * console.log(value); // "abcDEF"
- * });
- *
- *
- * @example <caption>Use on function calling callback in regular style</caption>
- * someFunction(a => {
- * console.log(a); // 5
- * });
- * var boundSomeFunction = Rx.Observable.bindNodeCallback(someFunction);
- * boundSomeFunction()
- * .subscribe(
- * value => {} // never gets called
- * err => console.log(err) // 5
- *);
- *
- *
- * @see {@link bindCallback}
- * @see {@link from}
- * @see {@link fromPromise}
- *
- * @param {function} func Function with a Node.js-style callback as the last parameter.
- * @param {function} [selector] A function which takes the arguments from the
- * callback and maps those to a value to emit 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 Node.js callback would
- * deliver.
- * @static true
- * @name bindNodeCallback
- * @owner Observable
- */
- BoundNodeCallbackObservable.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 BoundNodeCallbackObservable(func, selector, args, this, scheduler);
- };
- };
- /** @deprecated internal use only */ BoundNodeCallbackObservable.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;
- var err = innerArgs.shift();
- if (err) {
- subject.error(err);
- }
- else 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(dispatch, 0, { source: this, subscriber: subscriber, context: this.context });
- }
- };
- return BoundNodeCallbackObservable;
- }(Observable_1.Observable));
- exports.BoundNodeCallbackObservable = BoundNodeCallbackObservable;
- function dispatch(state) {
- var self = this;
- var source = state.source, subscriber = state.subscriber, context = state.context;
- // XXX: cast to `any` to access to the private field in `source`.
- var _a = source, callbackFunc = _a.callbackFunc, args = _a.args, scheduler = _a.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;
- var err = innerArgs.shift();
- if (err) {
- self.add(scheduler.schedule(dispatchError, 0, { err: err, subject: subject }));
- }
- else 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) {
- self.add(scheduler.schedule(dispatchError, 0, { err: errorObject_1.errorObject.e, subject: subject }));
- }
- }
- self.add(subject.subscribe(subscriber));
- }
- 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=BoundNodeCallbackObservable.js.map
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