/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.apache.cocoon.woody.util;
import java.io.IOException;
import java.io.StringReader;
import java.util.Iterator;
import java.util.Map;
import org.apache.avalon.framework.CascadingRuntimeException;
import org.apache.cocoon.components.flow.FlowHelper;
import org.apache.cocoon.components.flow.javascript.fom.FOM_JavaScriptFlowHelper;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Function;
import org.mozilla.javascript.JavaScriptException;
import org.mozilla.javascript.Script;
import org.mozilla.javascript.Scriptable;
import org.w3c.dom.Element;
/**
* Helper methods to use JavaScript in various locations of the Woody configuration files
* such as event listeners and bindings.
*
* @author <a href="http://www.apache.org/~sylvain/">Sylvain Wallez</a>
* @version CVS $Id: JavaScriptHelper.java,v 1.10 2004/04/30 22:57:22 joerg Exp $
*/
public class JavaScriptHelper {
/**
* A shared root scope, avoiding to recreate a new one each time.
*/
private static Scriptable _rootScope = null;
/**
* Build a script with the content of a DOM element.
*
* @param element the element containing the script
* @return the compiled script
* @throws IOException
*/
public static Script buildScript(Element element) throws IOException {
String jsText = DomHelper.getElementText(element);
String sourceName = DomHelper.getSystemIdLocation(element);
Context ctx = Context.enter();
Script script;
try {
script = ctx.compileReader(
getRootScope(), //scope
new StringReader(jsText), // in
sourceName == null ? "<unknown>" : sourceName, // sourceName
DomHelper.getLineLocation(element), // lineNo
null // securityDomain
);
} finally {
Context.exit();
}
return script;
}
/**
* Build a function with the content of a DOM element.
*
* @param element the element containing the function body
* @param argumentNames names of the function arguments
* @return the compiled function
* @throws IOException
*/
public static Function buildFunction(Element element, String[] argumentNames) throws IOException {
// Enclose the script text with a function declaration
StringBuffer buffer = new StringBuffer("function foo(");
for (int i = 0; i < argumentNames.length; i++) {
if (i > 0) {
buffer.append(',');
}
buffer.append(argumentNames[i]);
}
buffer.append(") {\n").append(DomHelper.getElementText(element)).append("\n}");
String jsText = buffer.toString();
String sourceName = DomHelper.getSystemIdLocation(element);
Context ctx = Context.enter();
Function func;
try {
func = ctx.compileFunction(
getRootScope(), //scope
jsText, // in
sourceName == null ? "<unknown>" : sourceName, // sourceName
DomHelper.getLineLocation(element) - 1, // lineNo, "-1" because we added "function..."
null // securityDomain
);
} finally {
Context.exit();
}
return func;
}
/**
* Get a root scope for building child scopes.
*
* @return an appropriate root scope
*/
public static Scriptable getRootScope() {
if (_rootScope == null) {
// Create it if never used up to now
Context ctx = Context.enter();
try {
_rootScope = ctx.initStandardObjects(null);
} finally {
Context.exit();
}
}
return _rootScope;
}
/**
* Get a parent scope for building a child scope. The request is searched for an existing scope
* that can be provided by a flowscript higher in the call stack, giving visibility to flowscript
* functions and global (session) variables.
*
* @param objectModel an objectModel where the flowscript scope will be searched (can be <code>null</code>).
* @return an appropriate parent scope.
*/
public static Scriptable getParentScope(Map objectModel) {
// Try to get the flowscript scope
Scriptable parentScope = null;
if (objectModel != null) {
parentScope = FOM_JavaScriptFlowHelper.getFOM_FlowScope(objectModel);
}
if (parentScope != null) {
return parentScope;
} else {
return getRootScope();
}
}
public static Object execScript(Script script, Map values, Map objectModel) throws JavaScriptException {
Context ctx = Context.enter();
try {
Scriptable parentScope = getParentScope(objectModel);
// Create a new local scope
Scriptable scope;
try {
scope = ctx.newObject(parentScope);
} catch (Exception e) {
// Should normally not happen
throw new CascadingRuntimeException("Cannont create script scope", e);
}
scope.setParentScope(parentScope);
// Populate the scope
Iterator iter = values.entrySet().iterator();
while(iter.hasNext()) {
Map.Entry entry = (Map.Entry)iter.next();
String key = (String)entry.getKey();
Object value = entry.getValue();
scope.put(key, scope, Context.toObject(value, scope));
}
if (objectModel != null) {
Object viewData = FlowHelper.getContextObject(objectModel);
if (viewData != null) {
scope.put("viewData", scope, Context.toObject(viewData, scope));
}
}
Object result = script.exec(ctx, scope);
return FlowHelper.unwrap(result);
} finally {
Context.exit();
}
}
public static Object callFunction(Function func, Object thisObject, Object[] arguments, Map objectModel) throws JavaScriptException {
Context ctx = Context.enter();
try {
Scriptable scope = getParentScope(objectModel);
if (objectModel != null) {
Object viewData = FlowHelper.getContextObject(objectModel);
if (viewData != null) {
// Create a new local scope to hold the view data
Scriptable newScope;
try {
newScope = ctx.newObject(scope);
} catch (Exception e) {
// Should normally not happen
throw new CascadingRuntimeException("Cannont create function scope", e);
}
newScope.setParentScope(scope);
scope = newScope;
scope.put("viewData", scope, Context.toObject(viewData, scope));
}
}
Object result = func.call(ctx, scope, thisObject == null? null: Context.toObject(thisObject, scope), arguments);
return FlowHelper.unwrap(result);
} finally {
Context.exit();
}
}
}