com.google.code.gwt.appcache.rebind.ApplicationCacheNetworkSectionGenerator.java Source code

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Here is the source code for com.google.code.gwt.appcache.rebind.ApplicationCacheNetworkSectionGenerator.java

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/*
 * Copyright 2009 Bart Guijt and others.
 * 
 * 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.google.code.gwt.appcache.rebind;

import java.util.Iterator;

import com.google.code.gwt.appcache.linker.IFrameAppCacheLinker;
import com.google.code.gwt.appcache.linker.NetworkSectionArtifact;
import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.TreeLogger.Type;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.dev.cfg.ModuleDef;
import com.google.gwt.dev.cfg.ModuleDefLoader;
import com.google.gwt.dev.cfg.Rule;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;

/**
 * Generates the entries in the 'Network' section in the Application Cache
 * manifest.
 * 
 * @author bguijt
 * @see com.google.code.gwt.appcache.linker.ApplicationCacheManifestLinker
 */
public class ApplicationCacheNetworkSectionGenerator extends Generator {

    @Override
    public String generate(TreeLogger logger, GeneratorContext context, String typeName)
            throws UnableToCompleteException {

        // Invoke the regular RPC generator:
        String result = rebindTypeByInheritedModule("com.google.gwt.user.RemoteService", logger, context, typeName);

        TypeOracle typeOracle = context.getTypeOracle();
        JClassType remoteService = typeOracle.findType(typeName);
        RemoteServiceRelativePath moduleRelativeUrl = remoteService.getAnnotation(RemoteServiceRelativePath.class);

        if (moduleRelativeUrl != null) {
            // add URL to network section:
            if (logger.isLoggable(Type.INFO)) {
                logger.log(Type.DEBUG,
                        "Found URL for NETWORK: section in cache-manifest: '" + moduleRelativeUrl.value() + "'");
            }
            NetworkSectionArtifact artifact = new NetworkSectionArtifact(IFrameAppCacheLinker.class,
                    moduleRelativeUrl.value());
            context.commitArtifact(logger, artifact);
        }

        return result;
    }

    /**
     * Invokes the deferred binding rule(s) in the specified module to the
     * specified typeName.
     * 
     * @param module the module (which is already inherited!) to use as 'parent'
     *          module
     * @param logger
     * @param context
     * @param typeName the name of the type to rebind
     * @throws UnableToCompleteException if the module can't provide a substitute
     * @return the rebound typeName, or <code>null</code> if no binding took place
     */
    private String rebindTypeByInheritedModule(String module, TreeLogger logger, GeneratorContext context,
            String typeName) throws UnableToCompleteException {
        ModuleDef rpcModule = ModuleDefLoader.loadFromClassPath(logger, module);
        Iterator<Rule> iter = rpcModule.getRules().iterator();
        while (iter.hasNext()) {
            Rule r = iter.next();
            if (r.isApplicable(logger, context, typeName)) {
                logger.log(TreeLogger.DEBUG, "The inherited module " + module + " found a rebinder for type "
                        + typeName + " by rule " + r);
                return r.realize(logger, context, typeName);
            }
        }
        logger.log(TreeLogger.WARN, "The inherit module rebinder did not rebind anything for type " + typeName
                + " in inherited module " + module);
        return null;
    }
}