/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.myfaces.view.facelets.tag.jstl.core;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.el.ELException;
import javax.el.ValueExpression;
import javax.el.VariableMapper;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.FaceletException;
import javax.faces.view.facelets.TagAttribute;
import javax.faces.view.facelets.TagAttributeException;
import javax.faces.view.facelets.TagConfig;
import javax.faces.view.facelets.TagHandler;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletAttribute;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletTag;
import org.apache.myfaces.view.facelets.FaceletCompositionContext;
import org.apache.myfaces.view.facelets.tag.jsf.ComponentSupport;
/**
* The basic iteration tag, accepting many different
* collection types and supporting subsetting and other
* functionality
*
* @author Jacob Hookom
* @author Andrew Robinson
* @version $Id: ForEachHandler.java,v 1.12 2008/07/13 19:01:43 rlubke Exp $
*/
@JSFFaceletTag(name="c:forEach")
public final class ForEachHandler extends TagHandler
{
private static class ArrayIterator implements Iterator<Object>
{
protected final Object array;
protected int i;
protected final int len;
public ArrayIterator(Object src)
{
this.i = 0;
this.array = src;
this.len = Array.getLength(src);
}
public boolean hasNext()
{
return this.i < this.len;
}
public Object next()
{
return Array.get(this.array, this.i++);
}
public void remove()
{
throw new UnsupportedOperationException();
}
}
/**
* If items specified:
* Iteration begins at the item located at the
* specified index. First item of the collection has
* index 0.
* If items not specified:
* Iteration begins with index set at the value
* specified.
*/
@JSFFaceletAttribute(className="int")
private final TagAttribute begin;
/**
* If items specified:
* Iteration ends at the item located at the
* specified index (inclusive).
* If items not specified:
* Iteration ends when index reaches the value
* specified.
*/
@JSFFaceletAttribute(className="int")
private final TagAttribute end;
/**
* Collection of items to iterate over.
*/
@JSFFaceletAttribute(className="javax.el.ValueExpression")
private final TagAttribute items;
/**
* Iteration will only process every step items of
* the collection, starting with the first one.
*/
@JSFFaceletAttribute(className="int")
private final TagAttribute step;
private final TagAttribute tranzient;
/**
* Name of the exported scoped variable for the
* current item of the iteration. This scoped
* variable has nested visibility. Its type depends
* on the object of the underlying collection.
*/
@JSFFaceletAttribute(className="java.lang.String")
private final TagAttribute var;
/**
* Name of the exported scoped variable for the
* status of the iteration.
*/
@JSFFaceletAttribute(className="java.lang.String")
private final TagAttribute varStatus;
/**
* @param config
*/
public ForEachHandler(TagConfig config)
{
super(config);
this.items = this.getAttribute("items");
this.var = this.getAttribute("var");
this.begin = this.getAttribute("begin");
this.end = this.getAttribute("end");
this.step = this.getAttribute("step");
this.varStatus = this.getAttribute("varStatus");
this.tranzient = this.getAttribute("transient");
if (this.items == null && this.begin != null && this.end == null)
{
throw new TagAttributeException(this.tag, this.begin,
"If the 'items' attribute is not specified, but the 'begin' attribute is, then the 'end' attribute is required");
}
}
public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, FaceletException,
ELException
{
int s = this.getBegin(ctx);
int e = this.getEnd(ctx);
int m = this.getStep(ctx);
Integer sO = this.begin != null ? Integer.valueOf(s) : null;
Integer eO = this.end != null ? Integer.valueOf(e) : null;
Integer mO = this.step != null ? Integer.valueOf(m) : null;
boolean t = this.getTransient(ctx);
Object src = null;
ValueExpression srcVE = null;
if (this.items != null)
{
srcVE = this.items.getValueExpression(ctx, Object.class);
src = srcVE.getValue(ctx);
}
else
{
byte[] b = new byte[e + 1];
for (int i = 0; i < b.length; i++)
{
b[i] = (byte) i;
}
src = b;
}
if (src != null)
{
Iterator<?> itr = this.toIterator(src);
if (itr != null)
{
int i = 0;
// move to start
while (i < s && itr.hasNext())
{
itr.next();
i++;
}
String v = this.getVarName(ctx);
String vs = this.getVarStatusName(ctx);
VariableMapper vars = ctx.getVariableMapper();
ValueExpression ve = null;
ValueExpression vO = this.capture(v, vars);
ValueExpression vsO = this.capture(vs, vars);
int mi = 0;
Object value = null;
try
{
boolean first = true;
while (i <= e && itr.hasNext())
{
value = itr.next();
// set the var
if (v != null)
{
if (t || srcVE == null)
{
ctx.setAttribute(v, value);
}
else
{
ve = this.getVarExpr(srcVE, src, value, i);
vars.setVariable(v, ve);
}
}
// set the varStatus
if (vs != null)
{
IterationStatus itrS = new IterationStatus(first, !itr.hasNext(), i, sO, eO, mO, value);
if (t || srcVE == null)
{
ctx.setAttribute(vs, itrS);
}
else
{
ve = new IterationStatusExpression(itrS);
vars.setVariable(vs, ve);
}
}
// execute body
this.nextHandler.apply(ctx, parent);
// increment steps
mi = 1;
while (mi < m && itr.hasNext())
{
itr.next();
mi++;
i++;
}
i++;
first = false;
}
}
finally
{
if (v != null)
{
vars.setVariable(v, vO);
}
if (vs != null)
{
vars.setVariable(vs, vsO);
}
}
}
}
if (FaceletCompositionContext.getCurrentInstance(ctx).
isMarkInitialStateAndIsRefreshTransientBuildOnPSS())
{
//Mark the parent component to be saved and restored fully.
ComponentSupport.markComponentToRestoreFully(ctx.getFacesContext(), parent);
}
}
private final ValueExpression capture(String name, VariableMapper vars)
{
if (name != null)
{
return vars.setVariable(name, null);
}
return null;
}
private final int getBegin(FaceletContext ctx)
{
if (this.begin != null)
{
return this.begin.getInt(ctx);
}
return 0;
}
private final int getEnd(FaceletContext ctx)
{
if (this.end != null)
{
return this.end.getInt(ctx);
}
return Integer.MAX_VALUE - 1; // hotspot bug in the JVM
}
private final int getStep(FaceletContext ctx)
{
if (this.step != null)
{
return this.step.getInt(ctx);
}
return 1;
}
private final boolean getTransient(FaceletContext ctx)
{
if (this.tranzient != null)
{
return this.tranzient.getBoolean(ctx);
}
return false;
}
private final ValueExpression getVarExpr(ValueExpression ve, Object src, Object value, int i)
{
if (src instanceof List || src.getClass().isArray())
{
return new IndexedValueExpression(ve, i);
}
else if (src instanceof Map && value instanceof Map.Entry)
{
return new MappedValueExpression(ve, (Map.Entry) value);
}
else if (src instanceof Collection)
{
return new IteratedValueExpression(ve, value);
}
throw new IllegalStateException("Cannot create VE for: " + src);
}
private final String getVarName(FaceletContext ctx)
{
if (this.var != null)
{
return this.var.getValue(ctx);
}
return null;
}
private final String getVarStatusName(FaceletContext ctx)
{
if (this.varStatus != null)
{
return this.varStatus.getValue(ctx);
}
return null;
}
private final Iterator<?> toIterator(Object src)
{
if (src == null)
{
return null;
}
else if (src instanceof Collection)
{
return ((Collection<?>) src).iterator();
}
else if (src instanceof Map)
{
return ((Map<?, ?>) src).entrySet().iterator();
}
else if (src.getClass().isArray())
{
return new ArrayIterator(src);
}
else
{
throw new TagAttributeException(this.tag, this.items, "Must evaluate to a Collection, Map, Array, or null.");
}
}
}