Package com.google.gwt.core.client

## Interface Callback<T,​F>

- Type Parameters:
    `T` - The type returned on success
    `F` - The type returned on failure

      public interface Callback<T,​F>

  A callback for any asynchronous call that can result in success or failure.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `onFailure​(F reason)` | Called when an asynchronous call fails to complete normally.
    `void` | `onSuccess​(T result)` | Called when an asynchronous call completes successfully.

- - ### Method Detail

    - #### onFailure

          void onFailure​(F reason)

      Called when an asynchronous call fails to complete normally.
      Parameters:
        `reason` - failure encountered

    - #### onSuccess

          void onSuccess​(T result)

      Called when an asynchronous call completes successfully.
      Parameters:
        `result` - the value returned