001 // Copyright 2004, 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.html;
016
017 import org.apache.hivemind.ApplicationRuntimeException;
018 import org.apache.hivemind.Location;
019 import org.apache.hivemind.Resource;
020 import org.apache.hivemind.util.Defense;
021 import org.apache.tapestry.*;
022 import org.apache.tapestry.asset.AssetSource;
023 import org.apache.tapestry.engine.IScriptSource;
024
025 import java.util.HashMap;
026 import java.util.Iterator;
027 import java.util.Map;
028
029 /**
030 * Works with the {@link Body}component to add a script (and perhaps some
031 * initialization) to the HTML response. [ <a
032 * href="../../../../../ComponentReference/Script.html">Component Reference
033 * </a>]
034 *
035 * @author Howard Lewis Ship
036 */
037
038 public abstract class Script extends AbstractComponent
039 {
040 /**
041 * A Map of input and output symbols visible to the body of the Script.
042 *
043 * @since 2.2
044 */
045
046 private Map _symbols;
047
048 /**
049 * Injected.
050 *
051 * @since 4.0
052 */
053
054 public abstract IScriptSource getScriptSource();
055
056 /**
057 * Constructs the symbols {@link Map}. This starts with the contents of the
058 * symbols parameter (if specified) to which is added any informal
059 * parameters. If both a symbols parameter and informal parameters are
060 * bound, then a copy of the symbols parameter's value is made (that is, the
061 * {@link Map}provided by the symbols parameter is read, but not modified).
062 */
063
064 private Map getInputSymbols()
065 {
066 Map result = new HashMap();
067
068 Map baseSymbols = getBaseSymbols();
069
070 if (baseSymbols != null) result.putAll(baseSymbols);
071
072 // Now, iterate through all the binding names (which includes both
073 // formal and informal parmeters). Skip the formal ones and
074 // access the informal ones.
075
076 Iterator i = getBindingNames().iterator();
077 while(i.hasNext())
078 {
079 String bindingName = (String) i.next();
080
081 // Skip formal parameters
082
083 if (getSpecification().getParameter(bindingName) != null) continue;
084
085 IBinding binding = getBinding(bindingName);
086
087 Object value = binding.getObject();
088
089 result.put(bindingName, value);
090 }
091
092 return result;
093 }
094
095 /**
096 * Gets the {@link IScript}for the correct script.
097 */
098
099 private IScript getParsedScript()
100 {
101 IAsset scriptAsset = getScriptAsset();
102 String scriptPath = getScriptPath();
103
104 // only one of the two is allowed
105 if (scriptAsset != null && scriptPath != null)
106 throw new ApplicationRuntimeException(HTMLMessages.multiAssetParameterError(getBinding("scriptAsset"),
107 getBinding("script")));
108
109 if (scriptPath == null && scriptAsset == null)
110 throw new ApplicationRuntimeException(HTMLMessages.noScriptPathError());
111
112 IScriptSource source = getScriptSource();
113
114 if (scriptPath != null)
115 {
116 // If the script path is relative, it should be relative to the
117 // Script component's
118 // container (i.e., relative to a page in the application).
119
120 Resource rootLocation = getContainer().getSpecification().getSpecificationLocation();
121
122 scriptAsset = getAssetSource().findAsset(rootLocation, getContainer().getSpecification(), scriptPath, getPage().getLocale(), getScriptLocation());
123 }
124
125 Defense.notNull(scriptAsset, "script");
126
127 try
128 {
129 return source.getScript(scriptAsset.getResourceLocation());
130 }
131 catch (RuntimeException ex)
132 {
133 throw new ApplicationRuntimeException(ex.getMessage(), this, getScriptLocation(), ex);
134 }
135
136 }
137
138 Location getScriptLocation()
139 {
140 Location location = null;
141
142 if (getBinding("script")!=null)
143 location = getBinding("script").getLocation();
144 else if (getBinding("scriptAsset")!=null)
145 location = getBinding("scriptAsset").getLocation();
146
147 return location;
148 }
149
150 protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
151 {
152 if (!cycle.isRewinding())
153 {
154 PageRenderSupport pageRenderSupport = TapestryUtils
155 .getPageRenderSupport(cycle, this);
156
157 _symbols = getInputSymbols();
158
159 getParsedScript().execute(this, cycle, pageRenderSupport, _symbols);
160 }
161
162 // Render the body of the Script;
163 renderBody(writer, cycle);
164 }
165
166 public abstract String getScriptPath();
167
168 public abstract IAsset getScriptAsset();
169
170 // injected
171 public abstract AssetSource getAssetSource();
172
173 // Parameter
174
175 public abstract Map getBaseSymbols();
176
177 /**
178 * Returns the complete set of symbols (input and output) from the script
179 * execution. This is visible to the body of the Script, but is cleared
180 * after the Script finishes rendering.
181 *
182 * @since 2.2
183 */
184
185 public Map getSymbols()
186 {
187 return _symbols;
188 }
189
190 protected void cleanupAfterRender(IRequestCycle cycle)
191 {
192 _symbols = null;
193
194 super.cleanupAfterRender(cycle);
195 }
196
197 }