/*******************************************************************************
* 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
*******************************************************************************/
package org.eclipse.jst.pagedesigner.preview;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.servlet.jsp.el.ELException;
import javax.servlet.jsp.el.FunctionMapper;
import javax.servlet.jsp.el.VariableResolver;
import org.apache.commons.el.ExpressionEvaluatorImpl;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IStorage;
import org.eclipse.core.runtime.CoreException;
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.PDPlugin;
import org.eclipse.jst.pagedesigner.jsp.core.el.JSFELParserHelper;
import org.eclipse.jst.pagedesigner.jsp.core.pagevar.IPageVariablesProvider;
import org.eclipse.jst.pagedesigner.jsp.core.pagevar.IVariableInfo;
/**
* This is a static class. But it has "session" concept in it. To make it static
* is only to simplify its use.
*
* This class currently is only used by TagConverter, when calculating the
* displayed string for resource bundle items.
*
* XXX: in the future, if we want to this to be non-static, we may incorportate
* it into the context of the tag converter.
*
* @author mengbo
* @version 1.5
*/
// TODO: we may consider support cache the properties.
public class PageExpressionContext {
private static final Logger _log = PDPlugin
.getLogger(PageExpressionContext.class);
static PageExpressionContext _current;
List _pageVarProviders = new ArrayList();
VariableResolver resolver = new SimpleVariableResolver();
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) {
// "Error"
_log.info("PageExpressionContext.Info.0", ex); //$NON-NLS-1$
}
}
/**
* this method is for design time expression evaluation. Currently it only
* handles
*
* @param expression
* @param expectedClass
* @param options
* XXX: not used today. In the future, we may support things like
* locale in options
* @return the result of evaluating the expression
* @throws ELException
*/
public Object evaluateExpression(String expression, Class expectedClass,
Map options) throws ELException {
expression = JSFELParserHelper.toJspElExpression(expression);
ExpressionEvaluatorImpl evaluator = new ExpressionEvaluatorImpl();
FunctionMapper mapper = new EmptyFunctionMapper();
return evaluator.evaluate(expression, expectedClass, resolver, mapper);
}
class SimpleVariableResolver implements VariableResolver {
/*
* (non-Javadoc)
*
* @see javax.servlet.jsp.el.VariableResolver#resolveVariable(java.lang.String)
*/
public Object resolveVariable(String varName) throws ELException {
// 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())) {
// ok we found.
if (vars[i].getMode() == IVariableInfo.RESOURCEBUNDLE) {
String resourceName = vars[i]
.getTypeInfoString();
IStorage s = null;
try {
s = LoadBundleUtil
.getLoadBundleResource(_prj,
resourceName);
} catch (CoreException ex) {
// "Error"
_log
.info(
"PageExpressionContext.Info.0", ex); //$NON-NLS-1$
}
if (s == null) {
throw new ELException();
}
InputStream input = null;
try {
input = new BufferedInputStream(s
.getContents());
Properties p = new Properties();
p.load(input);
return p;
} catch (CoreException e) {
throw new ELException(e);
} catch (IOException e) {
throw new ELException(e);
} finally {
ResourceUtils.ensureClosed(input);
}
}
}
}
}
}
}
throw new ELException("Can't find: " + varName); //$NON-NLS-1$
}
}
static class EmptyFunctionMapper implements FunctionMapper {
/*
* (non-Javadoc)
*
* @see javax.servlet.jsp.el.FunctionMapper#resolveFunction(java.lang.String,
* java.lang.String)
*/
public Method resolveFunction(String arg0, String arg1) {
return null;
}
}
}