Class webdriver.promise.Node_

code »
webdriver.promise.Promise.<(T|null)>
  └ webdriver.promise.Deferred
      └ webdriver.promise.Node_

A single node in an webdriver.promise.ControlFlow's task tree.

Constructor

webdriver.promise.Node_ ( flow )
Parameters
flow: !webdriver.promise.ControlFlow
The flow this instance belongs to.
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Instance Methods

Defined in webdriver.promise.Node_

Returns
This node's parent.
Returns
The root of this node's tree.
code »setParent ( parent )
Parameters
parent: webdriver.promise.Node_
This node's new parent.

Defined in webdriver.promise.Deferred

code »errback ( opt_error )

Rejects this promise. If the error is itself a promise, this instance will be chained to it and be rejected with the error's resolved value.

Parameters
opt_error: *=
The rejection reason, typically either a Error or a string.
code »fulfill ( opt_value )

Resolves this promise with the given value. If the value is itself a promise and not a reference to this deferred, this instance will wait for it before resolving.

Parameters
opt_value: T=
The fulfilled value.
code »reject ( opt_error )

Rejects this promise. If the error is itself a promise, this instance will be chained to it and be rejected with the error's resolved value.

Parameters
opt_error: *=
The rejection reason, typically either a Error or a string.

Removes all of the listeners previously registered on this deferred.

Throws
Error
If this deferred has already been resolved.

Defined in webdriver.promise.Promise.<(T|null)>

code »cancel ( reason )

Cancels the computation of this promise's value, rejecting the promise in the process.

Parameters
reason: *
The reason this promise is being cancelled. If not an Error, one will be created using the value's string representation.
Returns
Whether this promise's value is still being computed.
code »<R> then ( opt_callback, opt_errback )!webdriver.promise.Promise.<R>

Registers listeners for when this instance is resolved. This function most overridden by subtypes.

Parameters
opt_callback: ?(function(T): (R|webdriver.promise.Promise.<R>))=
The function to call if this promise is successfully resolved. The function should expect a single argument: the promise's resolved value.
opt_errback: ?(function(*): (R|webdriver.promise.Promise.<R>))=
The function to call if this promise is rejected. The function should expect a single argument: the rejection reason.
Returns
A new promise which will be resolved with the result of the invoked callback.

Registers a listener for when this promise is rejected. This is synonymous with the catch clause in a synchronous API:


   // Synchronous API:
   try {
     doSynchronousWork();
   } catch (ex) {
     console.error(ex);
   }

   // Asynchronous promise API:
   doAsynchronousWork().thenCatch(function(ex) {
     console.error(ex);
   });
 
Parameters
errback: function(*): (R|webdriver.promise.Promise.<R>)
The function to call if this promise is rejected. The function should expect a single argument: the rejection reason.
Returns
A new promise which will be resolved with the result of the invoked callback.

Registers a listener to invoke when this promise is resolved, regardless of whether the promise's value was successfully computed. This function is synonymous with the finally clause in a synchronous API:


   // Synchronous API:
   try {
     doSynchronousWork();
   } finally {
     cleanUp();
   }

   // Asynchronous promise API:
   doAsynchronousWork().thenFinally(cleanUp);
 
Note: similar to the finally clause, if the registered callback returns a rejected promise or throws an error, it will silently replace the rejection error (if any) from this promise:

   try {
     throw Error('one');
   } finally {
     throw Error('two');  // Hides Error: one
   }

   webdriver.promise.rejected(Error('one'))
       .thenFinally(function() {
         throw Error('two');  // Hides Error: one
       });
 
Parameters
callback: function(): (R|webdriver.promise.Promise.<R>)
The function to call when this promise is resolved.
Returns
A promise that will be fulfilled with the callback result.

Instance Properties

Defined in webdriver.promise.Node_

Defined in webdriver.promise.Deferred

Represents the eventual value of a completed operation. Each promise may be in one of three states: pending, resolved, or rejected. Each promise starts in the pending state and may make a single transition to either a fulfilled or failed state.

This class is based on the Promise/A proposal from CommonJS. Additional functions are provided for API compatibility with Dojo Deferred objects.

Static Properties