/*
* 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.cocoon.template.instruction;
import java.util.Iterator;
import java.util.Stack;
import org.apache.cocoon.el.objectmodel.ObjectModel;
import org.apache.cocoon.el.parsing.StringTemplateParser;
import org.apache.cocoon.el.parsing.Subst;
import org.apache.cocoon.template.environment.ErrorHolder;
import org.apache.cocoon.template.environment.ExecutionContext;
import org.apache.cocoon.template.environment.ParsingContext;
import org.apache.cocoon.template.script.Invoker;
import org.apache.cocoon.template.script.event.Event;
import org.apache.cocoon.template.script.event.StartElement;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.cocoon.xml.util.NamespacesTable;
import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
/**
* @version SVN $Id: ForEach.java 569795 2007-08-26 10:08:56Z danielf $
*/
public class ForEach extends Instruction {
protected static final Iterator NULL_ITER = new Iterator() {
public boolean hasNext() {
return true;
}
public Object next() {
return null;
}
public void remove() {
// EMPTY
}
};
private final Subst items;
private final Subst var;
private final Subst varStatus;
private final Subst begin;
private final Subst end;
private final Subst step;
public ForEach(ParsingContext parsingContext, StartElement raw, Attributes attrs, Stack stack)
throws SAXException {
super(raw);
String name = raw.getLocalName();
Locator locator = getLocation();
String items = attrs.getValue("items");
String select = attrs.getValue("select");
StringTemplateParser expressionCompiler = parsingContext.getStringTemplateParser();
this.var = expressionCompiler.compileExpr(attrs.getValue("var"), null, locator);
this.varStatus = expressionCompiler.compileExpr(attrs.getValue("varStatus"), null, locator);
this.begin = expressionCompiler.compileInt(attrs.getValue("begin"), name, locator);
this.end = expressionCompiler.compileInt(attrs.getValue("end"), name, locator);
this.step = expressionCompiler.compileInt(attrs.getValue("step"), name, locator);
if (items == null) {
if (select == null && (begin == null || end == null)) {
throw new SAXParseException("forEach: \"select\", \"items\", or both \"begin\" and \"end\" must be specified",
locator, null);
}
} else if (select != null) {
throw new SAXParseException("forEach: only one of \"select\" or \"items\" may be specified",
locator, null);
}
this.items = expressionCompiler.compileExpr(items == null ? select : items, null, locator);
}
public Event execute(final XMLConsumer consumer,
ObjectModel objectModel, ExecutionContext executionContext,
MacroContext macroContext, NamespacesTable namespaces, Event startEvent, Event endEvent)
throws SAXException {
Iterator iter = null;
int begin, end, step;
String var = null, varStatus = null;
try {
iter = (this.items != null )
? this.items.getIterator(objectModel)
: NULL_ITER;
begin = this.begin == null
? 0
: this.begin.getIntValue(objectModel);
end = this.end == null
? Integer.MAX_VALUE
: this.end.getIntValue(objectModel);
step = this.step == null
? 1
: this.step.getIntValue(objectModel);
if ( this.var != null )
var = this.var.getStringValue(objectModel);
if ( this.varStatus != null )
varStatus = this.varStatus.getStringValue(objectModel);
} catch (Exception exc) {
throw new SAXParseException(exc.getMessage(),
getLocation(), exc);
} catch (Error err) {
throw new SAXParseException(err.getMessage(),
getLocation(), new ErrorHolder(err));
}
objectModel.markLocalContext();
int i = 0;
// Move to the begin row
while (i < begin && iter.hasNext()) {
iter.next();
i++;
}
LoopTagStatus status = null;
if (varStatus != null) {
status = new LoopTagStatus();
status.setBegin(begin);
status.setEnd(end);
status.setStep(step);
status.setFirst(true);
objectModel.put(varStatus, status);
}
int skipCounter, count = 1;
while (i <= end && iter.hasNext()) {
objectModel.markLocalContext();
Object value = iter.next();
objectModel.put(ObjectModel.CONTEXTBEAN, value);
if (var != null) {
objectModel.put(var, value);
}
if (status != null) {
status.setIndex(i);
status.setCount(count);
status.setFirst(i == begin);
status.setCurrent(value);
status.setLast((i == end || !iter.hasNext()));
}
Invoker.execute(consumer, objectModel, executionContext,
macroContext, namespaces, getNext(), getEndInstruction());
// Skip rows
skipCounter = step;
while (--skipCounter > 0 && iter.hasNext()) {
iter.next();
}
// Increase index
i += step;
count++;
objectModel.cleanupLocalContext();
}
objectModel.cleanupLocalContext();
return getEndInstruction().getNext();
}
}