/**
* Copyright 2010 Google 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 org.waveprotocol.box.webclient.client;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
import org.waveprotocol.box.common.comms.jso.WaveViewSnapshotJsoImpl;
import org.waveprotocol.box.webclient.common.SnapshotSerializer;
import org.waveprotocol.box.webclient.common.communication.callback.SimpleCallback;
import org.waveprotocol.wave.client.debug.logger.DomLogger;
import org.waveprotocol.wave.common.logging.LoggerBundle;
import org.waveprotocol.wave.communication.gwt.JsonMessage;
import org.waveprotocol.wave.communication.json.JsonException;
import org.waveprotocol.wave.model.id.InvalidIdException;
import org.waveprotocol.wave.model.id.WaveId;
import org.waveprotocol.wave.model.operation.OperationException;
import org.waveprotocol.wave.model.wave.InvalidParticipantAddress;
import org.waveprotocol.wave.model.wave.data.DocumentFactory;
import org.waveprotocol.wave.model.wave.data.WaveViewData;
import org.waveprotocol.wave.model.waveref.WaveRef;
import org.waveprotocol.wave.util.escapers.GwtWaverefEncoder;
/**
* Helper class to fetch wavelet snapshots using the snapshot fetch service.
*
* @author josephg@gmail.com (Joseph Gentle)
*/
public final class SnapshotFetcher {
private static final LoggerBundle LOG = new DomLogger("SnapshotFetcher");
private static final String FETCH_URL_BASE = "/fetch";
private SnapshotFetcher() {
}
private static String getUrl(WaveRef waveRef) {
String pathSegment = GwtWaverefEncoder.encodeToUriPathSegment(waveRef);
return FETCH_URL_BASE + "/" + pathSegment;
}
/**
* Fetches a wave view snapshot from the static fetch servlet.
*
* @param waveId The wave to fetch
* @param callback A callback through which the fetched wave will be returned.
*/
public static void fetchWave(WaveId waveId,
final SimpleCallback<WaveViewData, Throwable> callback,
final DocumentFactory<?> docFactory) {
String url = getUrl(WaveRef.of(waveId));
LOG.trace().log("Fetching wavelet ", waveId.toString(), " at ", url);
RequestBuilder requestBuilder = new RequestBuilder(RequestBuilder.GET, url);
requestBuilder.setCallback(new RequestCallback() {
@Override
public void onResponseReceived(Request request, Response response) {
LOG.trace().log("Snapshot response recieved: ", response.getText());
// Pull the snapshot out of the response object and return it using
// the provided callback function.
if (response.getStatusCode() != Response.SC_OK) {
callback.onFailure(
new RequestException("Got back status code " + response.getStatusCode()));
} else if (!response.getHeader("Content-Type").startsWith("application/json")) {
callback.onFailure(new RuntimeException("Fetch service did not return json"));
} else {
WaveViewData waveView;
try {
WaveViewSnapshotJsoImpl snapshot = JsonMessage.parse(response.getText());
waveView = SnapshotSerializer.deserializeWave(snapshot, docFactory);
} catch (OperationException e) {
callback.onFailure(e);
return;
} catch (InvalidParticipantAddress e) {
callback.onFailure(e);
return;
} catch (InvalidIdException e) {
callback.onFailure(e);
return;
} catch (JsonException e) {
callback.onFailure(e);
return;
}
callback.onSuccess(waveView);
}
}
@Override
public void onError(Request request, Throwable exception) {
LOG.error().log("Snapshot error: ", exception);
callback.onFailure(exception);
}
});
try {
requestBuilder.send();
} catch (RequestException e) {
callback.onFailure(e);
}
}
}