/*******************************************************************************
* Copyright (c) 2006 Sybase, Inc. and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Sybase, Inc. - initial API and implementation
* Oracle - move to pluggable EL resolving
*******************************************************************************/
package org.eclipse.jst.pagedesigner.preview;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.servlet.jsp.el.ELException;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IStorage;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jst.jsf.common.ui.internal.logging.Logger;
import org.eclipse.jst.jsf.common.ui.internal.utils.ResourceUtils;
import org.eclipse.jst.jsf.core.internal.tld.LoadBundleUtil;
import org.eclipse.jst.pagedesigner.IJMTConstants;
import org.eclipse.jst.pagedesigner.PDPlugin;
import org.eclipse.jst.pagedesigner.jsp.core.pagevar.IPageVariablesProvider;
import org.eclipse.jst.pagedesigner.jsp.core.pagevar.IVariableInfo;
import org.w3c.dom.Element;
/**
* This is a static class. But it has "session" concept in it. To make it static
* is only to simplify its use.
*
* @author mengbo, ian.trimble@oracle.com
*/
public class PageExpressionContext {
private static final Logger _log = PDPlugin.getLogger(PageExpressionContext.class);
static PageExpressionContext _current;
List _pageVarProviders = new ArrayList();
private IProject _prj;
/**
* @param prj
*/
public PageExpressionContext(IProject prj) {
_prj = prj;
}
/**
* reset the context.
*/
public static void reset() {
_current = null;
}
/**
* Initialize the current context
* @param prj
*/
public static void initialize(IProject prj) {
_current = new PageExpressionContext(prj);
}
/**
* @return the current context
*/
public static PageExpressionContext getCurrent() {
return _current;
}
/**
* @param provider
*/
public void pushPageVarProvider(IPageVariablesProvider provider) {
_pageVarProviders.add(provider);
}
/**
* @param provider
*/
public void popPageVarProvider(IPageVariablesProvider provider) {
try {
_pageVarProviders.remove(_pageVarProviders.size() - 1);
} catch (Exception ex) {
_log.info("PageExpressionContext.Info.0", ex); //$NON-NLS-1$
}
}
/**
* This method is for design time expression evaluation.
*
* @param expression
* @param expectedClass
* @param options Current Element is passed with a key of "ELEMENT"
* @return the result of evaluating the expression
* @throws ELException
*/
public Object evaluateExpression(String expression, Class expectedClass, Map options)
throws ELException {
//Bug 319317 - Third-party plug-in providing javax.servlet.jsp.el version 2.1 or greater breaks WPE preview
String ret = expression;
if (options != null) {
Object objElement = options.get("ELEMENT"); //$NON-NLS-1$
if (objElement instanceof Element) {
ret = ELValueResolver.resolve((Element)objElement, expression);
}
}
return ret;
}
/**
* Gets an Object associated with a page variable.
* @param varName Page variable name.
* @return The Object associated with the named page variable, or null if the Object cannot be
* located.
*/
public Object getPageVariable(String varName) {
Object ret = null;
// reverse order.
for (int k = _pageVarProviders.size() - 1; k >= 0; k--) {
IPageVariablesProvider _pageVars = (IPageVariablesProvider) _pageVarProviders.get(k);
if (_pageVars != null) {
IVariableInfo[] vars = _pageVars.getBeanInfos();
if (vars != null) {
for (int i = 0; i < vars.length; i++) {
if (varName.equals(vars[i].getName())) {
if (vars[i].getMode() == IVariableInfo.RESOURCEBUNDLE) {
String resourceName = vars[i].getTypeInfoString();
IStorage storage = null;
try {
storage = LoadBundleUtil.getLoadBundleResource(_prj, resourceName);
} catch (CoreException cex) {
_log.info("PageExpressionContext.Info.0", cex); //$NON-NLS-1$
}
if (storage != null) {
InputStream input = null;
try {
input = new BufferedInputStream(storage.getContents());
Properties properties = new Properties();
properties.load(input);
ret = properties;
} catch (Exception ignored) {
//ignore - we'll return null
} finally {
ResourceUtils.ensureClosed(input);
}
}
}
}
}
}
}
}
return ret;
}
static class ELValueResolver {
static List<IELValueResolver> elValueResolvers;
public static String resolve(final Element element, final String elExpression) {
String value = elExpression;
if (elValueResolvers == null) {
readELValueResolvers();
}
for (IELValueResolver elValueResolver: elValueResolvers) {
value = elValueResolver.resolve(element, value);
}
return value;
}
private static void readELValueResolvers() {
elValueResolvers = new ArrayList<IELValueResolver>();
final IExtensionPoint pdExtPt =
Platform.getExtensionRegistry().getExtensionPoint(
PDPlugin.getPluginId(), IJMTConstants.EXTENSION_POINT_PAGEDESIGNER);
final IExtension[] extensions = pdExtPt.getExtensions();
for (final IExtension extension: extensions) {
final IConfigurationElement[] configElements = extension.getConfigurationElements();
for (final IConfigurationElement configElement: configElements) {
if (configElement.getName().equals("elValueResolver")) { //$NON-NLS-1$
try {
final Object objValueResolver = configElement.createExecutableExtension("class"); //$NON-NLS-1$
if (objValueResolver instanceof IELValueResolver) {
if (configElement.getContributor().getName().startsWith("org.eclipse.jst")) { //$NON-NLS-1$
//add to end (give precedence to contributor-provided resolvers)
elValueResolvers.add((IELValueResolver)objValueResolver);
} else {
//add at beginning (give precedence to contributor-provided resolvers)
elValueResolvers.add(0, (IELValueResolver)objValueResolver);
}
}
} catch(CoreException ce) {
PDPlugin.log("Error reading extensions for: " + configElement.toString(), ce); //$NON-NLS-1$
}
}
}
}
}
}
}