samples/mobilewebapp/src/main/java/com/google/gwt/sample/core/linker/SimpleAppCacheLinker.java - gwt - Git at Google

 /*
  * Copyright 2011 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 com.google.gwt.sample.core.linker;

 import com.google.gwt.core.ext.LinkerContext;
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.linker.AbstractLinker;
 import com.google.gwt.core.ext.linker.Artifact;
 import com.google.gwt.core.ext.linker.ArtifactSet;
 import com.google.gwt.core.ext.linker.EmittedArtifact;
 import com.google.gwt.core.ext.linker.LinkerOrder;
 import com.google.gwt.core.ext.linker.LinkerOrder.Order;
 import com.google.gwt.core.ext.linker.impl.SelectionInformation;

 import java.util.Arrays;
 import java.util.Date;

 /**
  * Linker for public path resources in the Application Cache.
  * <p>
  * <strong>Warning</strong>This linker sends all permutations to clients,
  * making it inappropriate for most production use.</strong>
  * <p>
  * To use:
  * <ol>
  * <li>Add {@code manifest="YOURMODULENAME/appcache.nocache.manifest"} to the
  * {@code <html>} tag in your base html file. E.g.,
  * {@code <html manifest="mymodule/appcache.nocache.manifest">}</li>
  * <li>Add a mime-mapping to your web.xml file:
  * <p>
  * <pre>{@code <mime-mapping>
  * <extension>manifest</extension>
  * <mime-type>text/cache-manifest</mime-type>
  * </mime-mapping>
  * }</pre>
  * </li>
  * </ol>
  * <p>
  * On every compile, this linker will regenerate the appcache.nocache.manifest
  * file with files from the public path of your module.
  * <p>
  * To obtain a manifest that contains other files in addition to those
  * generated by this linker, create a class that inherits from this one
  * and overrides {@code otherCachedFiles()}, and use it as a linker instead:
  * <p>
  * <pre><blockquote>
  * {@code @Shardable}
  * public class MyAppCacheLinker extends AbstractAppCacheLinker {
  *   {@code @Override}
  *   protected String[] otherCachedFiles() {
  *     return new String[] {"/MyApp.html","/MyApp.css"};
  *   }
  * }
  * </blockquote></pre>
  */
 @LinkerOrder(Order.POST)
 public class SimpleAppCacheLinker extends AbstractLinker {

   private static final String MANIFEST = "appcache.nocache.manifest";

   @Override
   public String getDescription() {
     return "AppCacheLinker";
   }

   @Override
   public ArtifactSet link(TreeLogger logger, LinkerContext context, ArtifactSet artifacts,
       boolean onePermutation)
       throws UnableToCompleteException {

     ArtifactSet toReturn = new ArtifactSet(artifacts);

     if (onePermutation) {
       return toReturn;
     }

     if (toReturn.find(SelectionInformation.class).isEmpty()) {
       logger.log(TreeLogger.INFO, "DevMode warning: Clobbering " + MANIFEST + " to allow debugging. "
           + "Recompile before deploying your app!");
       artifacts = null;
     }

     // Create the general cache-manifest resource for the landing page:
     toReturn.add(emitLandingPageCacheManifest(context, logger, artifacts));
     return toReturn;
   }

   /**
    * Override this method to force the linker to also include more files
    * in the manifest.
    */
   protected String[] otherCachedFiles() {
     return null;
   }

   /**
    * Creates the cache-manifest resource specific for the landing page.
    *
    * @param context the linker environment
    * @param logger the tree logger to record to
    * @param artifacts {@code null} to generate an empty cache manifest
    */
   private Artifact<?> emitLandingPageCacheManifest(LinkerContext context, TreeLogger logger,
       ArtifactSet artifacts)
       throws UnableToCompleteException {
     StringBuilder publicSourcesSb = new StringBuilder();
     StringBuilder staticResoucesSb = new StringBuilder();

     if (artifacts != null) {
       // Iterate over all emitted artifacts, and collect all cacheable artifacts
       for (@SuppressWarnings("rawtypes") Artifact artifact : artifacts) {
         if (artifact instanceof EmittedArtifact) {
           EmittedArtifact ea = (EmittedArtifact) artifact;
           String pathName = ea.getPartialPath();
           if (pathName.endsWith("symbolMap")
               || pathName.endsWith(".xml.gz")
               || pathName.endsWith("rpc.log")
               || pathName.endsWith("gwt.rpc")
               || pathName.endsWith("manifest.txt")
               || pathName.startsWith("rpcPolicyManifest")
               || pathName.startsWith("soycReport")) {
             // skip these resources
           } else {
             publicSourcesSb.append(pathName + "\n");
           }
         }
       }

       String[] cacheExtraFiles = getCacheExtraFiles();
       for (int i = 0; i < cacheExtraFiles.length; i++) {
         staticResoucesSb.append(cacheExtraFiles[i]);
         staticResoucesSb.append("\n");
       }
     }

     // build cache list
     StringBuilder sb = new StringBuilder();
     sb.append("CACHE MANIFEST\n");
     sb.append("# Unique id #" + (new Date()).getTime() + "." + Math.random() + "\n");
     // we have to generate this unique id because the resources can change but
     // the hashed cache.html files can remain the same.
     sb.append("# Note: must change this every time for cache to invalidate\n");
     sb.append("\n");
     sb.append("CACHE:\n");
     sb.append("# Static app files\n");
     sb.append(staticResoucesSb.toString());
     sb.append("\n# Generated app files\n");
     sb.append(publicSourcesSb.toString());
     sb.append("\n\n");
     sb.append("# All other resources require the user to be online.\n");
     sb.append("NETWORK:\n");
     sb.append("*\n");

     logger.log(TreeLogger.INFO, "Be sure your landing page's <html> tag declares a manifest:"
         + " <html manifest=" + context.getModuleFunctionName() + "/" + MANIFEST + "\">");

     // Create the manifest as a new artifact and return it:
     return emitString(logger, sb.toString(), MANIFEST);
   }

   /**
    * Obtains the extra files to include in the manifest. Ensures the returned
    * array is not null.
    */
   private String[] getCacheExtraFiles() {
     String[] cacheExtraFiles = otherCachedFiles();
     return cacheExtraFiles == null ?
         new String[0] : Arrays.copyOf(cacheExtraFiles, cacheExtraFiles.length);
   }
 }
	/*
	* Copyright 2011 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 com.google.gwt.sample.core.linker;

	import com.google.gwt.core.ext.LinkerContext;
	import com.google.gwt.core.ext.TreeLogger;
	import com.google.gwt.core.ext.UnableToCompleteException;
	import com.google.gwt.core.ext.linker.AbstractLinker;
	import com.google.gwt.core.ext.linker.Artifact;
	import com.google.gwt.core.ext.linker.ArtifactSet;
	import com.google.gwt.core.ext.linker.EmittedArtifact;
	import com.google.gwt.core.ext.linker.LinkerOrder;
	import com.google.gwt.core.ext.linker.LinkerOrder.Order;
	import com.google.gwt.core.ext.linker.impl.SelectionInformation;

	import java.util.Arrays;
	import java.util.Date;

	/**
	* Linker for public path resources in the Application Cache.
	* <p>
	* <strong>Warning</strong>This linker sends all permutations to clients,
	* making it inappropriate for most production use.</strong>
	* <p>
	* To use:
	* <ol>
	* <li>Add {@code manifest="YOURMODULENAME/appcache.nocache.manifest"} to the
	* {@code <html>} tag in your base html file. E.g.,
	* {@code <html manifest="mymodule/appcache.nocache.manifest">}</li>
	* <li>Add a mime-mapping to your web.xml file:
	* <p>
	* <pre>{@code <mime-mapping>
	* <extension>manifest</extension>
	* <mime-type>text/cache-manifest</mime-type>
	* </mime-mapping>
	* }</pre>
	* </li>
	* </ol>
	* <p>
	* On every compile, this linker will regenerate the appcache.nocache.manifest
	* file with files from the public path of your module.
	* <p>
	* To obtain a manifest that contains other files in addition to those
	* generated by this linker, create a class that inherits from this one
	* and overrides {@code otherCachedFiles()}, and use it as a linker instead:
	* <p>
	* <pre><blockquote>
	* {@code @Shardable}
	* public class MyAppCacheLinker extends AbstractAppCacheLinker {
	* {@code @Override}
	* protected String[] otherCachedFiles() {
	* return new String[] {"/MyApp.html","/MyApp.css"};
	* }
	* }
	* </blockquote></pre>
	*/
	@LinkerOrder(Order.POST)
	public class SimpleAppCacheLinker extends AbstractLinker {

	private static final String MANIFEST = "appcache.nocache.manifest";

	@Override
	public String getDescription() {
	return "AppCacheLinker";
	}

	@Override
	public ArtifactSet link(TreeLogger logger, LinkerContext context, ArtifactSet artifacts,
	boolean onePermutation)
	throws UnableToCompleteException {

	ArtifactSet toReturn = new ArtifactSet(artifacts);

	if (onePermutation) {
	return toReturn;
	}

	if (toReturn.find(SelectionInformation.class).isEmpty()) {
	logger.log(TreeLogger.INFO, "DevMode warning: Clobbering " + MANIFEST + " to allow debugging. "
	+ "Recompile before deploying your app!");
	artifacts = null;
	}

	// Create the general cache-manifest resource for the landing page:
	toReturn.add(emitLandingPageCacheManifest(context, logger, artifacts));
	return toReturn;
	}

	/**
	* Override this method to force the linker to also include more files
	* in the manifest.
	*/
	protected String[] otherCachedFiles() {
	return null;
	}

	/**
	* Creates the cache-manifest resource specific for the landing page.
	*
	* @param context the linker environment
	* @param logger the tree logger to record to
	* @param artifacts {@code null} to generate an empty cache manifest
	*/
	private Artifact<?> emitLandingPageCacheManifest(LinkerContext context, TreeLogger logger,
	ArtifactSet artifacts)
	throws UnableToCompleteException {
	StringBuilder publicSourcesSb = new StringBuilder();
	StringBuilder staticResoucesSb = new StringBuilder();

	if (artifacts != null) {
	// Iterate over all emitted artifacts, and collect all cacheable artifacts
	for (@SuppressWarnings("rawtypes") Artifact artifact : artifacts) {
	if (artifact instanceof EmittedArtifact) {
	EmittedArtifact ea = (EmittedArtifact) artifact;
	String pathName = ea.getPartialPath();
	if (pathName.endsWith("symbolMap")
	\|\| pathName.endsWith(".xml.gz")
	\|\| pathName.endsWith("rpc.log")
	\|\| pathName.endsWith("gwt.rpc")
	\|\| pathName.endsWith("manifest.txt")
	\|\| pathName.startsWith("rpcPolicyManifest")
	\|\| pathName.startsWith("soycReport")) {
	// skip these resources
	} else {
	publicSourcesSb.append(pathName + "\n");
	}
	}
	}

	String[] cacheExtraFiles = getCacheExtraFiles();
	for (int i = 0; i < cacheExtraFiles.length; i++) {
	staticResoucesSb.append(cacheExtraFiles[i]);
	staticResoucesSb.append("\n");
	}
	}

	// build cache list
	StringBuilder sb = new StringBuilder();
	sb.append("CACHE MANIFEST\n");
	sb.append("# Unique id #" + (new Date()).getTime() + "." + Math.random() + "\n");
	// we have to generate this unique id because the resources can change but
	// the hashed cache.html files can remain the same.
	sb.append("# Note: must change this every time for cache to invalidate\n");
	sb.append("\n");
	sb.append("CACHE:\n");
	sb.append("# Static app files\n");
	sb.append(staticResoucesSb.toString());
	sb.append("\n# Generated app files\n");
	sb.append(publicSourcesSb.toString());
	sb.append("\n\n");
	sb.append("# All other resources require the user to be online.\n");
	sb.append("NETWORK:\n");
	sb.append("*\n");

	logger.log(TreeLogger.INFO, "Be sure your landing page's <html> tag declares a manifest:"
	+ " <html manifest=" + context.getModuleFunctionName() + "/" + MANIFEST + "\">");

	// Create the manifest as a new artifact and return it:
	return emitString(logger, sb.toString(), MANIFEST);
	}

	/**
	* Obtains the extra files to include in the manifest. Ensures the returned
	* array is not null.
	*/
	private String[] getCacheExtraFiles() {
	String[] cacheExtraFiles = otherCachedFiles();
	return cacheExtraFiles == null ?
	new String[0] : Arrays.copyOf(cacheExtraFiles, cacheExtraFiles.length);
	}
	}