com.avos.avoscloud.FindCallback Maven / Gradle / Ivy

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package com.avos.avoscloud;

import java.util.List;

/**
 * 
 * A FindCallback is used to run code after a AVQuery is used to fetch a list of AVObjects in a
 * background thread.
 * 
 * 
 * 
 * The easiest way to use a FindCallback is through an anonymous inner class. Override the done
 * function to specify what the callback should do after the fetch is complete. The done function
 * will be run in the UI thread, while the fetch happens in a background thread. This ensures that
 * the UI does not freeze while the fetch happens.
 * 
 * 
 * For example, this sample code fetches all objects of class "MyClass". It calls a different
 * function depending on whether the fetch succeeded or not.
 * 
 * 
 * AVQuery query = AVQuery.getQuery("MyClass"); query.findInBackground(new
 * FindCallback() { public void done(List objects, AVException e) { if (e ==
 * null) { objectsWereRetrievedSuccessfully(objects); } else { objectRetrievalFailed(); } } });
 */

public abstract class FindCallback extends AVCallback> {
  /**
   * Override this function with the code you want to run after the fetch is complete.
   * 
   * @param avObjects The objects matching the query, or null if it failed.
   * @param avException The exception raised by the find, or null if it succeeded.
   */
  public abstract void done(List avObjects, AVException avException);

  protected final void internalDone0(List returnValue, AVException e) {
    done(returnValue, e);
  }
}