PendingResult

Kotlin |Java

public abstract class PendingResult<R extends Result>

Known direct subclasses

Batch, OptionalPendingResult

`Batch`	Handles a batch of `PendingResult` items.
`OptionalPendingResult`	Each `OptionalPendingResult` is a `PendingResult` with additional support for non-blocking accessors.

Represents a pending result from calling an API method in Google Play services. The final result object from a PendingResultis of type R, which can be retrieved in one of two ways.

via blocking calls to await, or await, or
via a callback by passing in an object implementing interface ResultCallback to setResultCallback.

After the result has been retrieved using await or delivered to the result callback, it is an error to attempt to retrieve the result again. It is the responsibility of the caller or callback receiver to release any resources associated with the returned result. Some result types may implement Releasable, in which case release should be used to free the associated resources.

Parameters
`<R extends Result>`	Result type

Summary

Public constructors
`PendingResult()`

Public methods
`abstract @NonNull R`	`await()` Blocks until the task is completed.
`abstract @NonNull R`	`await(long time, @NonNull TimeUnit units)` Blocks until the task is completed or has timed out waiting for the result.
`abstract void`	`cancel()` Requests that the PendingResult be canceled.
`abstract boolean`	`isCanceled()` Indicates whether the pending result has been canceled either due to calling `disconnect` or calling `cancel` directly on the pending result or an enclosing `Batch`.
`abstract void`	`setResultCallback(@NonNull ResultCallback<Object> callback)` Set the callback here if you want the result to be delivered via a callback when the result is ready.
`abstract void`	`setResultCallback( @NonNull ResultCallback<Object> callback, long time, @NonNull TimeUnit units )` Set the callback here if you want the result to be delivered via a callback when the result is ready or has timed out waiting for the result.
`@NonNull TransformedResult<S>`	`<S extends Result> then(@NonNull ResultTransform<Object, S> transform)` Transforms the result by making another API call.

Public constructors

PendingResult

public PendingResult()

Public methods

await

public abstract @NonNull R await()

Blocks until the task is completed. This is not allowed on the UI thread. The returned result object can have an additional failure mode of INTERRUPTED.

await

public abstract @NonNull R await(long time, @NonNull TimeUnit units)

Blocks until the task is completed or has timed out waiting for the result. This is not allowed on the UI thread. The returned result object can have an additional failure mode of either INTERRUPTED or TIMEOUT.

cancel

public abstract void cancel()

Requests that the PendingResult be canceled. If the result is available, but not consumed it will be released. If the result is set after cancelation was requested it is immediately released.

onResult will never be called, await will return a failed result with CANCELED.

isCanceled

public abstract boolean isCanceled()

Indicates whether the pending result has been canceled either due to calling disconnect or calling cancel directly on the pending result or an enclosing Batch.

setResultCallback

public abstract void setResultCallback(@NonNull ResultCallback<Object> callback)

Set the callback here if you want the result to be delivered via a callback when the result is ready.

setResultCallback

public abstract void setResultCallback(
    @NonNull ResultCallback<Object> callback,
    long time,
    @NonNull TimeUnit units
)

Set the callback here if you want the result to be delivered via a callback when the result is ready or has timed out waiting for the result. The returned result object can have an additional failure mode of TIMEOUT.

then

public @NonNull TransformedResult<S> <S extends Result> then(@NonNull ResultTransform<Object, S> transform)

Transforms the result by making another API call.

If the result is successful, then onSuccess will be called to make the additional API call that yields the transformed result. If the result is a failure, then onFailure will be called to (optionally) allow modification of failure status.

If the result implements Releasable, then release will be called once the transform has been applied.

Multiple API calls can be chained together by making subsequent calls to then and the final result can be received by an instance of specified via andFinally. For example:

final DriveFolder rootFolder = Drive.DriveApi.getRootFolder(mApiClient);
Drive.DriveApi.newDriveContents(mApiClient)
         .then(new ResultTransform<DriveContentsResult, DriveFileResult>() {
             @Override
             public PendingResult<DriveFileResult> onSuccess(DriveContentsResult result) {
                 DriveContents driveContents = result.getDriveContents();

                 // Write content to DriveContents
                 OutputStream outputStream = driveContents.getOutputStream();
                 PrintWriter writer = new PrintWriter(outputStream);
                 writer.write("Hello World!");
                 writer.close();

                 MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
                         .setTitle("hello.txt")
                         .setMimeType("text/plain")
                         .build();

                 // Create a file on root folder
                 return rootFolder.createFile(mApiClient, changeSet, driveContents);
             }
         })
         .then(new ResultTransform<DriveFileResult, MetadataBufferResult>() {
             @Override
             public PendingResult<MetadataBufferResult> onSuccess(DriveFileResult result) {
                 // Fetch the updated root folder contents
                 return rootFolder.listChildren(mApiClient)
             }
         })
         .andFinally(new ResultCallbacks<MetadataBufferResult>() {
             @Override
             public void onSuccess(MetadataBufferResult result) {
                 // All API calls were successful.
             }

             @Override
             public void onFailure(Status status) {
                 // An API call failed.
             }
         });

All ResultTransforms will be run on a worker thread. These transforms therefore must not interact with UI elements, but they may perform brief background work (not requiring more than a few seconds). If ResultCallbacks are specified, these will be called on the thread specified by setHandler or on the main thread by default.

If disconnect is called before a series of transforms completes the transforms will continue to run in the background until the last one completes. In this case, ResultCallbacks will not be called. Note that this may cause memory leaks if background transformations are long-running. For long background tasks, consider using an .

Note: it is an error to use multiple GoogleApiClients for various API calls within subsequent ResultTransforms. Behavior is undefined if calls don't use the same GoogleApiClient.