/*
* Copyright 2010 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.facebook.android;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import android.content.Context;
import android.os.Bundle;
/**
* A sample implementation of asynchronous API requests. This class provides
* the ability to execute API methods and have the call return immediately,
* without blocking the calling thread. This is necessary when accessing the
* API in the UI thread, for instance. The request response is returned to
* the caller via a callback interface, which the developer must implement.
*
* This sample implementation simply spawns a new thread for each request,
* and makes the API call immediately. This may work in many applications,
* but more sophisticated users may re-implement this behavior using a thread
* pool, a network thread, a request queue, or other mechanism. Advanced
* functionality could be built, such as rate-limiting of requests, as per
* a specific application's needs.
*
* @see RequestListener
* The callback interface.
*
* @author Jim Brusstar (jimbru@fb.com),
* Yariv Sadan (yariv@fb.com),
* Luke Shepard (lshepard@fb.com)
*/
public class AsyncFacebookRunner {
Facebook fb;
public AsyncFacebookRunner(Facebook fb) {
this.fb = fb;
}
/**
* Invalidate the current user session by removing the access token in
* memory, clearing the browser cookies, and calling auth.expireSession
* through the API. The application will be notified when logout is
* complete via the callback interface.
*
* Note that this method is asynchronous and the callback will be invoked
* in a background thread; operations that affect the UI will need to be
* posted to the UI thread or an appropriate handler.
*
* @param context
* The Android context in which the logout should be called: it
* should be the same context in which the login occurred in
* order to clear any stored cookies
* @param listener
* Callback interface to notify the application when the request
* has completed.
* @param state
* An arbitrary object used to identify the request when it
* returns to the callback. This has no effect on the request
* itself.
*/
public void logout(final Context context,
final RequestListener listener,
final Object state) {
new Thread() {
@Override public void run() {
try {
String response = fb.logout(context);
if (response.length() == 0 || response.equals("false")){
listener.onFacebookError(new FacebookError(
"auth.expireSession failed"), state);
return;
}
listener.onComplete(response, state);
} catch (FileNotFoundException e) {
listener.onFileNotFoundException(e, state);
} catch (MalformedURLException e) {
listener.onMalformedURLException(e, state);
} catch (IOException e) {
listener.onIOException(e, state);
}
}
}.start();
}
public void logout(final Context context, final RequestListener listener) {
logout(context, listener, /* state */ null);
}
/**
* Make a request to Facebook's old (pre-graph) API with the given
* parameters. One of the parameter keys must be "method" and its value
* should be a valid REST server API method.
*
* See http://developers.facebook.com/docs/reference/rest/
*
* Note that this method is asynchronous and the callback will be invoked
* in a background thread; operations that affect the UI will need to be
* posted to the UI thread or an appropriate handler.
*
* Example:
* <code>
* Bundle parameters = new Bundle();
* parameters.putString("method", "auth.expireSession", new Listener());
* String response = request(parameters);
* </code>
*
* @param parameters
* Key-value pairs of parameters to the request. Refer to the
* documentation: one of the parameters must be "method".
* @param listener
* Callback interface to notify the application when the request
* has completed.
* @param state
* An arbitrary object used to identify the request when it
* returns to the callback. This has no effect on the request
* itself.
*/
public void request(Bundle parameters,
RequestListener listener,
final Object state) {
request(null, parameters, "GET", listener, state);
}
public void request(Bundle parameters, RequestListener listener) {
request(null, parameters, "GET", listener, /* state */ null);
}
/**
* Make a request to the Facebook Graph API without any parameters.
*
* See http://developers.facebook.com/docs/api
*
* Note that this method is asynchronous and the callback will be invoked
* in a background thread; operations that affect the UI will need to be
* posted to the UI thread or an appropriate handler.
*
* @param graphPath
* Path to resource in the Facebook graph, e.g., to fetch data
* about the currently logged authenticated user, provide "me",
* which will fetch http://graph.facebook.com/me
* @param listener
* Callback interface to notify the application when the request
* has completed.
* @param state
* An arbitrary object used to identify the request when it
* returns to the callback. This has no effect on the request
* itself.
*/
public void request(String graphPath,
RequestListener listener,
final Object state) {
request(graphPath, new Bundle(), "GET", listener, state);
}
public void request(String graphPath, RequestListener listener) {
request(graphPath, new Bundle(), "GET", listener, /* state */ null);
}
/**
* Make a request to the Facebook Graph API with the given string parameters
* using an HTTP GET (default method).
*
* See http://developers.facebook.com/docs/api
*
* Note that this method is asynchronous and the callback will be invoked
* in a background thread; operations that affect the UI will need to be
* posted to the UI thread or an appropriate handler.
*
* @param graphPath
* Path to resource in the Facebook graph, e.g., to fetch data
* about the currently logged authenticated user, provide "me",
* which will fetch http://graph.facebook.com/me
* @param parameters
* key-value string parameters, e.g. the path "search" with
* parameters "q" : "facebook" would produce a query for the
* following graph resource:
* https://graph.facebook.com/search?q=facebook
* @param listener
* Callback interface to notify the application when the request
* has completed.
* @param state
* An arbitrary object used to identify the request when it
* returns to the callback. This has no effect on the request
* itself.
*/
public void request(String graphPath,
Bundle parameters,
RequestListener listener,
final Object state) {
request(graphPath, parameters, "GET", listener, state);
}
public void request(String graphPath,
Bundle parameters,
RequestListener listener) {
request(graphPath, parameters, "GET", listener, /* state */ null);
}
/**
* Make a request to the Facebook Graph API with the given HTTP method and
* string parameters. Note that binary data parameters (e.g. pictures) are
* not yet supported by this helper function.
*
* See http://developers.facebook.com/docs/api
*
* Note that this method is asynchronous and the callback will be invoked
* in a background thread; operations that affect the UI will need to be
* posted to the UI thread or an appropriate handler.
*
* @param graphPath
* Path to resource in the Facebook graph, e.g., to fetch data
* about the currently logged authenticated user, provide "me",
* which will fetch http://graph.facebook.com/me
* @param parameters
* key-value string parameters, e.g. the path "search" with
* parameters {"q" : "facebook"} would produce a query for the
* following graph resource:
* https://graph.facebook.com/search?q=facebook
* @param httpMethod
* http verb, e.g. "POST", "DELETE"
* @param listener
* Callback interface to notify the application when the request
* has completed.
* @param state
* An arbitrary object used to identify the request when it
* returns to the callback. This has no effect on the request
* itself.
*/
public void request(final String graphPath,
final Bundle parameters,
final String httpMethod,
final RequestListener listener,
final Object state) {
new Thread() {
@Override public void run() {
try {
String resp = fb.request(graphPath, parameters, httpMethod);
listener.onComplete(resp, state);
} catch (FileNotFoundException e) {
listener.onFileNotFoundException(e, state);
} catch (MalformedURLException e) {
listener.onMalformedURLException(e, state);
} catch (IOException e) {
listener.onIOException(e, state);
}
}
}.start();
}
/**
* Callback interface for API requests.
*
* Each method includes a 'state' parameter that identifies the calling
* request. It will be set to the value passed when originally calling the
* request method, or null if none was passed.
*/
public static interface RequestListener {
/**
* Called when a request completes with the given response.
*
* Executed by a background thread: do not update the UI in this method.
*/
public void onComplete(String response, Object state);
/**
* Called when a request has a network or request error.
*
* Executed by a background thread: do not update the UI in this method.
*/
public void onIOException(IOException e, Object state);
/**
* Called when a request fails because the requested resource is
* invalid or does not exist.
*
* Executed by a background thread: do not update the UI in this method.
*/
public void onFileNotFoundException(FileNotFoundException e,
Object state);
/**
* Called if an invalid graph path is provided (which may result in a
* malformed URL).
*
* Executed by a background thread: do not update the UI in this method.
*/
public void onMalformedURLException(MalformedURLException e,
Object state);
/**
* Called when the server-side Facebook method fails.
*
* Executed by a background thread: do not update the UI in this method.
*/
public void onFacebookError(FacebookError e, Object state);
}
}