org.stjs.bridge.rsvp

Class Promise<Result,FailResult>

java.lang.Object

org.stjs.bridge.rsvp.Promise<Result,FailResult>

public final class Promise<Result,FailResult>
extends Object

Constructor Summary

Constructors

Constructor and Description
Promise(org.stjs.javascript.functions.Callback2<org.stjs.javascript.functions.Callback1<Result>,org.stjs.javascript.functions.Callback1<FailResult>> handler) Constructs a new Promise instance where the resolution or rejection state is controlled by the specified handler function.

Method Summary

Methods

Modifier and Type	Method and Description
Promise<Result,FailResult>	then(org.stjs.javascript.functions.Callback1<? super Result> success) Calls the specified callback when the promise is resolved.
Promise<Result,FailResult>	then(org.stjs.javascript.functions.Callback1<? super Result> success, org.stjs.javascript.functions.Callback1<? super FailResult> failure) Calls one of the specified callbacks when the promise is resolved or rejected respectively.
<NewResult,NewFailResult> Promise<NewResult,NewFailResult>	thenPromise(org.stjs.javascript.functions.Function1<? super Result,Promise<NewResult,NewFailResult>> success) Calls the specified success callback with the resolution value as argument when the promise is resolved.
<NewResult,NewFailResult> Promise<NewResult,NewFailResult>	thenPromise(org.stjs.javascript.functions.Function1<? super Result,Promise<NewResult,NewFailResult>> success, org.stjs.javascript.functions.Function1<? super FailResult,Promise<NewResult,NewFailResult>> failure) Calls the specified callbacks when the promise is resolved or rejected respectively.
<NewResult> Promise<NewResult,FailResult>	thenReturn(org.stjs.javascript.functions.Function1<? super Result,NewResult> success) Calls the specified success callback with the resolution value as argument when the promise is resolved.
<NewResult,NewFailResult> Promise<NewResult,NewFailResult>	thenReturn(org.stjs.javascript.functions.Function1<? super Result,NewResult> success, org.stjs.javascript.functions.Function1<? super FailResult,NewFailResult> failure) Calls the specified callbacks when the promise is resolved or rejected respectively.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Promise

public Promise(org.stjs.javascript.functions.Callback2<org.stjs.javascript.functions.Callback1<Result>,org.stjs.javascript.functions.Callback1<FailResult>> handler)

Constructs a new Promise instance where the resolution or rejection state is controlled by the specified handler function.

 Promise promise = new RSVP.Promise((resolve, reject) {
   // succeed
   resolve(value);
   // or reject
   reject(error);
 });

 promise.then(resolveValue -> {
     // success
   },
   rejectValue -> {
     // failure
   }
 );
 

Once a promise has been resolved or rejected, it cannot be resolved or rejected again.

Here is an example of a simple XHR2 wrapper written using RSVP.js:

 Function1 getJSON = url -> {
   Promise promise = new RSVP.Promise(resolve, reject -> {
     XMLHttpRequest client = new XMLHttpRequest();
     client.open("GET", url);
     client.onreadystatechange = handler;
     client.responseType = "json";
     client.setRequestHeader("Accept", "application/json");
     client.send();

     Callback0 handler = () -> {
       if (client.readyState === this.DONE) {
         if (client.status === 200) {
           resolve(client.response);
         } else {
           reject(client);
         }
       }
     };
   });
   return promise;
 };

 getJSON.$invoke("/posts.json").then(
   json -> {
     // continue
   },
   error -> {
     // handle errors
   }
 );
 

Method Detail

then

public Promise<Result,FailResult> then(org.stjs.javascript.functions.Callback1<? super Result> success)

Calls the specified callback when the promise is resolved. The specified callback receives the resolution value as parameter.

Then next chained callback is called immediately after the specified callback finishes.

The callback does not transform the type of the value passed to the next chained resolution or rejection callbacks.

Parameters:

success - a callback executed when the promise is resolved.

Returns:

a promise that can be chained with more callbacks

then

public Promise<Result,FailResult> then(org.stjs.javascript.functions.Callback1<? super Result> success,
                              org.stjs.javascript.functions.Callback1<? super FailResult> failure)

Calls one of the specified callbacks when the promise is resolved or rejected respectively. The specified callbacks receives the resolution/rejection values as parameter.

Then next chained callback is called immediately after the specified callback finishes.

The callbacks does not transform the type of the value passed to the next chained resolution or rejection callbacks.

Parameters:

success - a callback executed when the promise is resolved.

failure - a callback executed when the promise is rejected.

Returns:

a promise that can be chained with more callbacks

thenReturn

public <NewResult> Promise<NewResult,FailResult> thenReturn(org.stjs.javascript.functions.Function1<? super Result,NewResult> success)

Calls the specified success callback with the resolution value as argument when the promise is resolved. The specified success callback must return a value that can either be the same object (eg: to allow further chaining) or any other object of any other type.

Then next chained success callback is called with the value returned by this success callback immediately after it returns.

Parameters:

success - a callback executed when the promise is resolved.

Returns:

a promise that can be chained with more callbacks

thenReturn

public <NewResult,NewFailResult> Promise<NewResult,NewFailResult> thenReturn(org.stjs.javascript.functions.Function1<? super Result,NewResult> success,
                                                                    org.stjs.javascript.functions.Function1<? super FailResult,NewFailResult> failure)

Calls the specified callbacks when the promise is resolved or rejected respectively. The specified callbacks receives the resolution/rejection values as parameter. The specified callbacks must return a value that can either be the same object (eg: to allow further chaining) or any other object of any other type.

Then next chained success or failure callbacks is called with the value returned by the respective callback immediately after it returns.

Parameters:

success - a callback executed when the promise is resolved.

failure - a callback executed when the promise is rejected.

Returns:

a promise that can be chained with more callbacks

thenPromise

public <NewResult,NewFailResult> Promise<NewResult,NewFailResult> thenPromise(org.stjs.javascript.functions.Function1<? super Result,Promise<NewResult,NewFailResult>> success)

Calls the specified success callback with the resolution value as argument when the promise is resolved. The specified success callback returns a new Promise with a potentially different return type.

Then next chained success callback is called when the returned promise is eventually resolved or rejected.

Parameters:

success - a callback executed when the promise is resolved.

Returns:

a promise that can be chained with more callbacks

thenPromise

public <NewResult,NewFailResult> Promise<NewResult,NewFailResult> thenPromise(org.stjs.javascript.functions.Function1<? super Result,Promise<NewResult,NewFailResult>> success,
                                                                     org.stjs.javascript.functions.Function1<? super FailResult,Promise<NewResult,NewFailResult>> failure)

Calls the specified callbacks when the promise is resolved or rejected respectively. The specified callbacks receives the resolution/rejection values as parameter. The specified callbacks return a new Promise with a potentially different return type.

Then next chained success or failure callbacks is called when the returned promise is eventually resolved or rejected.

Parameters:

success - a callback executed when the promise is resolved.

failure - a callback executed when the promise is rejected.

Returns:

a promise that can be chained with more callbacks