/*
* 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.stream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import com.facebook.android.AsyncFacebookRunner;
import com.facebook.android.Facebook;
import com.facebook.android.FacebookError;
import com.facebook.android.Util;
import com.facebook.android.AsyncFacebookRunner.RequestListener;
/**
* A handler for the stream page. It's responsible for
* fetching the stream data from the API and storing it
* in a local file based cache. It uses the helper class
* StreamRenderer to render the stream.
*
* @author yariv
*/
public class StreamHandler extends Handler {
private static final String CACHE_FILE = "cache.txt";
/**
* Called by the dispatcher to render the stream page.
*/
public void go() {
dispatcher.getWebView().addJavascriptInterface(
new StreamJsHandler(this), "app");
// first try to load the cached data
try {
String cached = FileIO.read(getActivity(), CACHE_FILE);
if (cached != null) {
JSONObject obj = new JSONObject(cached);
dispatcher.loadData(StreamRenderer.render(obj));
}
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
Facebook fb = Session.restore(getActivity()).getFb();
new AsyncFacebookRunner(fb).request("me/home",
new StreamRequestListener());
}
public class StreamRequestListener implements RequestListener {
public void onComplete(String response, final Object state) {
try {
JSONObject obj = Util.parseJson(response);
// try to cache the result
try {
FileIO.write(getActivity(), response, CACHE_FILE);
} catch (IOException e) {
e.printStackTrace();
}
// Convert the result into an HTML string and then load it
// into the WebView in the UI thread.
final String html = StreamRenderer.render(obj);
getActivity().runOnUiThread(new Runnable() {
public void run() {
dispatcher.loadData(html);
}
});
} catch (JSONException e) {
Log.e("stream", "JSON Error:" + e.getMessage());
} catch (FacebookError e) {
Log.e("stream", "Facebook Error:" + e.getMessage());
}
}
public void onFacebookError(FacebookError e, final Object state) {
Log.e("stream", "Facebook Error:" + e.getMessage());
}
public void onFileNotFoundException(FileNotFoundException e,
final Object state) {
Log.e("stream", "Resource not found:" + e.getMessage());
}
public void onIOException(IOException e, final Object state) {
Log.e("stream", "Network Error:" + e.getMessage());
}
public void onMalformedURLException(MalformedURLException e,
final Object state) {
Log.e("stream", "Invalid URL:" + e.getMessage());
}
}
}