/**
* 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.wave.client.gadget.renderer;
import org.waveprotocol.wave.model.id.WaveletName;
/**
* Gadget data store interface. Defines methods to fetch Gadget data for
* rendering. The implementing classes may access the Google Gadget Servers
* and cache the data.
* See: http://code.google.com/apis/gadgets/docs/spec.html for more details.
*
* TODO(user): This is really a GadgetRenderer, as it prepares a gadget
* for rendering and retrieves everything required to do so. So this should
* really be renamed and return a GadgetInstance.
*
*/
public interface GadgetDataStore {
/**
* Data callback interface to asynchronously receive the data or error
* information from the store.
*/
public interface DataCallback {
/**
* Called by the store when the requested gadget data is ready.
* TODO(user): Change to GadgetData class when implemented.
*
* @param metadata The gadget metadata object passed from the store.
* @param securityToken The security token for this gadget, may be null.
*/
void onDataReady(GadgetMetadata metadata, String securityToken);
/**
* Called by the store if the requested metadata cannot be retrieved.
*
* @param message error message.
* @param exception the exception that caused the error (can be null).
*/
void onError(String message, Throwable exception);
}
/**
* Requests gadget data from the store.
*
* @param gadgetSpecUrl the gadget specification URL that identified the
* gadget.
* @param waveletName The Wavelet name for this gadget.
* @param instanceId The gadget instance id.
* @param receiveDataCommand callback that receives the result.
*/
void getGadgetData(final String gadgetSpecUrl, WaveletName waveletName,
int instanceId, final DataCallback receiveDataCommand);
}