import { SchedulerLike, SchedulerAction } from '../types';
import { Observable } from '../Observable';
import { AsyncSubject } from '../AsyncSubject';
import { Subscriber } from '../Subscriber';
import { map } from '../operators/map';
import { canReportError } from '../util/canReportError';
import { isArray } from '../util/isArray';
import { isScheduler } from '../util/isScheduler';
// tslint:disable:max-line-length
/** @deprecated resultSelector is no longer supported, use a mapping function. */
export function bindCallback(callbackFunc: Function, resultSelector: Function, scheduler?: SchedulerLike): (...args: any[]) => Observable<any>;
export function bindCallback<R1, R2, R3, R4>(callbackFunc: (callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): () => Observable<any[]>;
export function bindCallback<R1, R2, R3>(callbackFunc: (callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): () => Observable<[R1, R2, R3]>;
export function bindCallback<R1, R2>(callbackFunc: (callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): () => Observable<[R1, R2]>;
export function bindCallback<R1>(callbackFunc: (callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): () => Observable<R1>;
export function bindCallback(callbackFunc: (callback: () => any) => any, scheduler?: SchedulerLike): () => Observable<void>;
export function bindCallback<A1, R1, R2, R3, R4>(callbackFunc: (arg1: A1, callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): (arg1: A1) => Observable<any[]>;
export function bindCallback<A1, R1, R2, R3>(callbackFunc: (arg1: A1, callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): (arg1: A1) => Observable<[R1, R2, R3]>;
export function bindCallback<A1, R1, R2>(callbackFunc: (arg1: A1, callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): (arg1: A1) => Observable<[R1, R2]>;
export function bindCallback<A1, R1>(callbackFunc: (arg1: A1, callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): (arg1: A1) => Observable<R1>;
export function bindCallback<A1>(callbackFunc: (arg1: A1, callback: () => any) => any, scheduler?: SchedulerLike): (arg1: A1) => Observable<void>;
export function bindCallback<A1, A2, R1, R2, R3, R4>(callbackFunc: (arg1: A1, arg2: A2, callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2) => Observable<any[]>;
export function bindCallback<A1, A2, R1, R2, R3>(callbackFunc: (arg1: A1, arg2: A2, callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2) => Observable<[R1, R2, R3]>;
export function bindCallback<A1, A2, R1, R2>(callbackFunc: (arg1: A1, arg2: A2, callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2) => Observable<[R1, R2]>;
export function bindCallback<A1, A2, R1>(callbackFunc: (arg1: A1, arg2: A2, callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2) => Observable<R1>;
export function bindCallback<A1, A2>(callbackFunc: (arg1: A1, arg2: A2, callback: () => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2) => Observable<void>;
export function bindCallback<A1, A2, A3, R1, R2, R3, R4>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3) => Observable<any[]>;
export function bindCallback<A1, A2, A3, R1, R2, R3>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3) => Observable<[R1, R2, R3]>;
export function bindCallback<A1, A2, A3, R1, R2>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3) => Observable<[R1, R2]>;
export function bindCallback<A1, A2, A3, R1>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3) => Observable<R1>;
export function bindCallback<A1, A2, A3>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, callback: () => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3) => Observable<void>;
export function bindCallback<A1, A2, A3, A4, R1, R2, R3, R4>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4) => Observable<any[]>;
export function bindCallback<A1, A2, A3, A4, R1, R2, R3>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4) => Observable<[R1, R2, R3]>;
export function bindCallback<A1, A2, A3, A4, R1, R2>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4) => Observable<[R1, R2]>;
export function bindCallback<A1, A2, A3, A4, R1>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4) => Observable<R1>;
export function bindCallback<A1, A2, A3, A4>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, callback: () => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4) => Observable<void>;
export function bindCallback<A1, A2, A3, A4, A5, R1, R2, R3, R4>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, callback: (res1: R1, res2: R2, res3: R3, res4: R4, ...args: any[]) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5) => Observable<any[]>;
export function bindCallback<A1, A2, A3, A4, A5, R1, R2, R3>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, callback: (res1: R1, res2: R2, res3: R3) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5) => Observable<[R1, R2, R3]>;
export function bindCallback<A1, A2, A3, A4, A5, R1, R2>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, callback: (res1: R1, res2: R2) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5) => Observable<[R1, R2]>;
export function bindCallback<A1, A2, A3, A4, A5, R1>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, callback: (res1: R1) => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5) => Observable<R1>;
export function bindCallback<A1, A2, A3, A4, A5>(callbackFunc: (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, callback: () => any) => any, scheduler?: SchedulerLike): (arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5) => Observable<void>;
export function bindCallback<A, R>(callbackFunc: (...args: Array<A | ((result: R) => any)>) => any, scheduler?: SchedulerLike): (...args: A[]) => Observable<R>;
export function bindCallback<A, R>(callbackFunc: (...args: Array<A | ((...results: R[]) => any)>) => any, scheduler?: SchedulerLike): (...args: A[]) => Observable<R[]>;
export function bindCallback(callbackFunc: Function, scheduler?: SchedulerLike): (...args: any[]) => Observable<any>;
// tslint:enable:max-line-length
/**
* Converts a callback API to a function that returns an Observable.
*
* <span class="informal">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.</span>
*
* `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.
*
* The last optional parameter - `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 {@link asyncScheduler} 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 were to 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, then the subscription of the resulting Observable
* will call the `next` function synchronously as well. If you want to defer that call,
* you may use {@link asyncScheduler} 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.
*
* ## Examples
*
* ### Convert jQuery's getJSON to an Observable API
* ```ts
* import { bindCallback } from 'rxjs';
* import * as jQuery from 'jquery';
*
* // Suppose we have jQuery.getJSON('/my/url', callback)
* const getJSONAsObservable = bindCallback(jQuery.getJSON);
* const result = getJSONAsObservable('/my/url');
* result.subscribe(x => console.log(x), e => console.error(e));
* ```
*
* ### Receive an array of arguments passed to a callback
* ```ts
* import { bindCallback } from 'rxjs';
*
* const someFunction = (a, b, c) => {
* console.log(a); // 5
* console.log(b); // 'some string'
* console.log(c); // {someProperty: 'someValue'}
* };
*
* const boundSomeFunction = bindCallback(someFunction);
* boundSomeFunction().subscribe(values => {
* console.log(values) // [5, 'some string', {someProperty: 'someValue'}]
* });
* ```
*
* ### Compare behaviour with and without async Scheduler
* ```ts
* import { bindCallback } from 'rxjs';
*
* function iCallMyCallbackSynchronously(cb) {
* cb();
* }
*
* const boundSyncFn = bindCallback(iCallMyCallbackSynchronously);
* const boundAsyncFn = 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!
* ```
*
* ### Use bindCallback on an object method
* ```ts
* import { bindCallback } from 'rxjs';
*
* const boundMethod = bindCallback(someObject.methodWithCallback);
* boundMethod.call(someObject) // make sure methodWithCallback has access to someObject
* .subscribe(subscriber);
* ```
*
* @see {@link bindNodeCallback}
* @see {@link from}
*
* @param {function} func A function with a callback as the last parameter.
* @param {SchedulerLike} [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.
* @name bindCallback
*/
export function bindCallback<T>(
callbackFunc: Function,
resultSelector?: Function|SchedulerLike,
scheduler?: SchedulerLike
): (...args: any[]) => Observable<T> {
if (resultSelector) {
if (isScheduler(resultSelector)) {
scheduler = resultSelector;
} else {
// DEPRECATED PATH
return (...args: any[]) => bindCallback(callbackFunc, scheduler)(...args).pipe(
map((args) => isArray(args) ? resultSelector(...args) : resultSelector(args)),
);
}
}
return function (this: any, ...args: any[]): Observable<T> {
const context = this;
let subject: AsyncSubject<T>;
const params = {
context,
subject,
callbackFunc,
scheduler,
};
return new Observable<T>(subscriber => {
if (!scheduler) {
if (!subject) {
subject = new AsyncSubject<T>();
const handler = (...innerArgs: any[]) => {
subject.next(innerArgs.length <= 1 ? innerArgs[0] : innerArgs);
subject.complete();
};
try {
callbackFunc.apply(context, [...args, handler]);
} catch (err) {
if (canReportError(subject)) {
subject.error(err);
} else {
console.warn(err);
}
}
}
return subject.subscribe(subscriber);
} else {
const state: DispatchState<T> = {
args, subscriber, params,
};
return scheduler.schedule<DispatchState<T>>(dispatch, 0, state);
}
});
};
}
interface DispatchState<T> {
args: any[];
subscriber: Subscriber<T>;
params: ParamsContext<T>;
}
interface ParamsContext<T> {
callbackFunc: Function;
scheduler: SchedulerLike;
context: any;
subject: AsyncSubject<T>;
}
function dispatch<T>(this: SchedulerAction<DispatchState<T>>, state: DispatchState<T>) {
const self = this;
const { args, subscriber, params } = state;
const { callbackFunc, context, scheduler } = params;
let { subject } = params;
if (!subject) {
subject = params.subject = new AsyncSubject<T>();
const handler = (...innerArgs: any[]) => {
const value = innerArgs.length <= 1 ? innerArgs[0] : innerArgs;
this.add(scheduler.schedule<NextState<T>>(dispatchNext, 0, { value, subject }));
};
try {
callbackFunc.apply(context, [...args, handler]);
} catch (err) {
subject.error(err);
}
}
this.add(subject.subscribe(subscriber));
}
interface NextState<T> {
subject: AsyncSubject<T>;
value: T;
}
function dispatchNext<T>(this: SchedulerAction<NextState<T>>, state: NextState<T>) {
const { value, subject } = state;
subject.next(value);
subject.complete();
}
interface ErrorState<T> {
subject: AsyncSubject<T>;
err: any;
}
function dispatchError<T>(this: SchedulerAction<ErrorState<T>>, state: ErrorState<T>) {
const { err, subject } = state;
subject.error(err);
}