/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-04 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery;
import org.exist.Namespaces;
import org.exist.dom.QName;
import org.exist.dom.memtree.MemTreeBuilder;
import org.exist.dom.memtree.NodeImpl;
import org.exist.util.XMLChar;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceIterator;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.QNameValue;
import org.w3c.dom.DOMException;
/**
* Represents a dynamic attribute constructor. The implementation differs from
* AttributeConstructor as the evaluation is not controlled by the surrounding
* element. The attribute name as well as its value are only determined at evaluation time,
* not at compile time.
*
* @author wolf
*/
public class DynamicAttributeConstructor extends NodeConstructor {
private Expression qnameExpr;
private Expression valueExpr;
private boolean replaceAttribute = false;
/**
* @param context
*/
public DynamicAttributeConstructor(XQueryContext context) {
super(context);
}
public void setNameExpr(Expression expr) {
this.qnameExpr = new Atomize(context, expr);
}
public Expression getNameExpr() {
return this.qnameExpr;
}
public void setContentExpr(Expression expr) {
this.valueExpr = expr;
}
public Expression getContentExpr() {
return this.valueExpr;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#analyze(org.exist.xquery.Expression)
*/
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
super.analyze(contextInfo);
contextInfo.setParent(this);
qnameExpr.analyze(contextInfo);
valueExpr.analyze(contextInfo);
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#eval(org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);}
if (contextItem != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());}
}
if (newDocumentContext)
{context.pushDocumentContext();}
NodeImpl node;
try {
final MemTreeBuilder builder = context.getDocumentBuilder();
builder.setReplaceAttributeFlag(replaceAttribute);
context.proceed(this, builder);
final Sequence nameSeq = qnameExpr.eval(contextSequence, contextItem);
if(!nameSeq.hasOne())
{throw new XPathException(this, "The name expression should evaluate to a single value");}
final Item qnItem = nameSeq.itemAt(0);
QName qn;
if (qnItem.getType() == Type.QNAME)
{qn = ((QNameValue) qnItem).getQName();}
else
try {
qn = QName.parse(context, nameSeq.getStringValue(), null);
} catch (final IllegalArgumentException e) {
throw new XPathException(this, ErrorCodes.XPTY0004, "'" + nameSeq.getStringValue() + "' is not a valid attribute name");
}
//Not in the specs but... makes sense
if(!XMLChar.isValidName(qn.getLocalPart()))
{throw new XPathException(this, ErrorCodes.XPTY0004, "'" + qn.getLocalPart() + "' is not a valid attribute name");}
if ("xmlns".equals(qn.getLocalPart()) && qn.getNamespaceURI().isEmpty())
{throw new XPathException(this, ErrorCodes.XQDY0044, "'" + qn.getLocalPart() + "' is not a valid attribute name");}
String value;
final Sequence valueSeq = valueExpr.eval(contextSequence, contextItem);
if(valueSeq.isEmpty())
{value = "";}
else {
final StringBuilder buf = new StringBuilder();
for(final SequenceIterator i = Atomize.atomize(valueSeq).iterate(); i.hasNext(); ) {
final Item next = i.nextItem();
buf.append(next.getStringValue());
if(i.hasNext())
{buf.append(' ');}
}
value = buf.toString();
}
value = DynamicAttributeConstructor.normalize(this, qn, value);
node = null;
try {
final int nodeNr = builder.addAttribute(qn, value);
node = builder.getDocument().getAttribute(nodeNr);
} catch (final DOMException e) {
throw new XPathException(this, ErrorCodes.XQDY0025, "element has more than one attribute '" + qn + "'");
}
} finally {
if (newDocumentContext)
{context.popDocumentContext();}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", node);}
return node;
}
public static String normalize(Expression expr, QName qn, String value) throws XPathException {
//normalize xml:id
if (qn.equals(Namespaces.XML_ID_QNAME)) {
value = StringValue.trimWhitespace(StringValue.collapseWhitespace(value));
if (!XMLChar.isValidNCName(value))
{throw new XPathException(expr, ErrorCodes.XQDY0091, "Value of xml:id attribute is not a valid NCName: " + value);}
}
return value;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
dumper.display("attribute ");
//TODO : remove curly braces if Qname
dumper.display("{");
qnameExpr.dump(dumper);
dumper.display("} ");
//TODO : handle empty value
dumper.display("{");
dumper.startIndent();
valueExpr.dump(dumper);
dumper.endIndent();
dumper.nl().display("}");
}
public String toString() {
//TODO : remove curly braces if Qname
//TODO : handle empty value
return "attribute " + "{" + qnameExpr.toString() + "} {" + valueExpr.toString() + "} ";
}
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
qnameExpr.resetState(postOptimization);
valueExpr.resetState(postOptimization);
}
public void accept(ExpressionVisitor visitor) {
visitor.visitAttribConstructor(this);
}
public void setReplaceAttributeFlag(boolean flag) {
replaceAttribute = flag;
}
}