ResultTransform

Kotlin |Java

public abstract class ResultTransform<R extends Result, S extends Result>

Transforms a Result by making a subsequent API call.

See also
`then`

Summary

Public constructors
`ResultTransform()`

Public methods
`final @NonNull PendingResult<S>`	`createFailedResult(@NonNull Status status)` Creates a failed result with the given `Status`.
`@NonNull Status`	`onFailure(@NonNull Status status)` Called when the PendingResult to be transformed returns a failure.
`abstract @Nullable PendingResult<S>`	`@WorkerThread onSuccess(@NonNull R result)` Transforms the result of a successful API call.

Public constructors

ResultTransform

public ResultTransform()

Public methods

createFailedResult

public final @NonNull PendingResult<S> createFailedResult(@NonNull Status status)

Creates a failed result with the given Status. In the event of an error during onSuccess, call this method and return the failed result.

Note: the PendingResult generated by this method must be returned directly from onSuccess. It is an error to call any methods on this PendingResult.

onFailure

public @NonNull Status onFailure(@NonNull Status status)

Called when the PendingResult to be transformed returns a failure. Default implementation simply propagates the failure, but subclasses may override for custom failure handling. This method is called on the main thread, unless overridden by setHandler.

Parameters
`@NonNull Status status`	The status of the failure.

Returns
`@NonNull Status`	The status of the result of the transformation. Must not be success or null.

onSuccess

@WorkerThread
public abstract @Nullable PendingResult<S> onSuccess(@NonNull R result)

Transforms the result of a successful API call. This method is called on a background thread and should not access UI elements.

Parameters
`@NonNull R result`	The successful result to be transformed. Never null. If this result is it will be automatically released after this transform is applied; it is not necessary to release the result inside onSuccess. It is an error to set callbacks on this result. Any callbacks set on this result will be overridden and will not be called.

Returns

Returns
`@Nullable PendingResult<S>`	The result of the transformation. Normally the result of another API call. To shortcut execution and directly yield a failure, return either: `null`, which is translated into a `Status` with code `ERROR`; or a specific failure created using `createFailedResult`.

@Nullable PendingResult<S>

The result of the transformation. Normally the result of another API call. To shortcut execution and directly yield a failure, return either:

null, which is translated into a Status with code ERROR; or
a specific failure created using createFailedResult.