001 // Copyright 2005 The Apache Software Foundation
002 //
003 // Licensed under the Apache License, Version 2.0 (the "License");
004 // you may not use this file except in compliance with the License.
005 // You may obtain a copy of the License at
006 //
007 // http://www.apache.org/licenses/LICENSE-2.0
008 //
009 // Unless required by applicable law or agreed to in writing, software
010 // distributed under the License is distributed on an "AS IS" BASIS,
011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012 // See the License for the specific language governing permissions and
013 // limitations under the License.
014
015 package org.apache.tapestry.enhance;
016
017 import org.apache.hivemind.Location;
018 import org.apache.hivemind.Resource;
019 import org.apache.hivemind.service.MethodSignature;
020 import org.apache.hivemind.util.Defense;
021 import org.apache.tapestry.IAsset;
022 import org.apache.tapestry.IScript;
023 import org.apache.tapestry.asset.AssetSource;
024 import org.apache.tapestry.engine.IScriptSource;
025 import org.apache.tapestry.spec.InjectSpecification;
026
027 import java.lang.reflect.Modifier;
028
029 /**
030 * Injects {@link org.apache.tapestry.IScript} instances directly into pages or components.
031 *
032 * @author Howard M. Lewis Ship
033 * @since 4.0
034 */
035 public class InjectScriptWorker implements InjectEnhancementWorker
036 {
037 private IScriptSource _source;
038
039 private AssetSource _assetSource;
040
041 public void performEnhancement(EnhancementOperation op, InjectSpecification spec)
042 {
043 String propertyName = spec.getProperty();
044 String scriptName = spec.getObject();
045 Location location = spec.getLocation();
046
047 injectScript(op, propertyName, scriptName, location);
048 }
049
050 /**
051 * Injects a script reference.
052 *
053 * @param op
054 * the enhancement operation
055 * @param propertyName
056 * the name of the property to inject
057 * @param scriptName
058 * the name of the script (relative to the location)
059 * @param location
060 * the location of the specification; primarily used as the base location for finding
061 * the script.
062 */
063
064 public void injectScript(EnhancementOperation op, String propertyName,
065 String scriptName, Location location)
066 {
067 Defense.notNull(op, "op");
068 Defense.notNull(propertyName, "propertyName");
069 Defense.notNull(scriptName, "scriptName");
070 Defense.notNull(location, "location");
071
072 op.claimReadonlyProperty(propertyName);
073
074 Class propertyType = EnhanceUtils.verifyPropertyType(op, propertyName, IScript.class);
075
076 // PropertyType will likely be either java.lang.Object or IScript
077
078 String methodName = op.getAccessorMethodName(propertyName);
079
080 Resource resource = location.getResource().getRelativeResource(scriptName);
081
082 // if can't find resource
083
084 if (resource.getResourceURL() == null)
085 {
086 IAsset scriptAsset = _assetSource.findAsset(location.getResource(), op.getSpecification(),
087 scriptName, null, location);
088
089 if (scriptAsset != null)
090 {
091 resource = scriptAsset.getResourceLocation();
092 }
093 }
094
095 DeferredScript script = new DeferredScriptImpl(resource, _source, location);
096
097 String fieldName = op.addInjectedField("_$script", DeferredScript.class, script);
098
099 MethodSignature sig = new MethodSignature(propertyType, methodName, null, null);
100
101 op.addMethod(Modifier.PUBLIC, sig, "return " + fieldName + ".getScript();", location);
102 }
103
104 public void setSource(IScriptSource source)
105 {
106 _source = source;
107 }
108
109 public void setAssetSource(AssetSource assetSource)
110 {
111 _assetSource = assetSource;
112 }
113 }