package net.sf.saxon.functions;
import net.sf.saxon.CollectionURIResolver;
import net.sf.saxon.expr.*;
import net.sf.saxon.om.EmptyIterator;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.AnyURIValue;
import javax.xml.transform.SourceLocator;
/**
* Implement the fn:collection() function. This is responsible for calling the
* registered {@link CollectionURIResolver}. For the effect of the default
* system-supplied CollectionURIResolver, see {@link StandardCollectionURIResolver}
*/
public class Collection extends SystemFunction {
private String expressionBaseURI = null;
public String getStaticBaseURI() {
return expressionBaseURI;
}
public void checkArguments(ExpressionVisitor visitor) throws XPathException {
if (expressionBaseURI == null) {
super.checkArguments(visitor);
expressionBaseURI = visitor.getStaticContext().getBaseURI();
}
}
public int computeSpecialProperties() {
return super.computeSpecialProperties() & ~StaticProperty.NON_CREATIVE &
StaticProperty.ORDERED_NODESET & StaticProperty.PEER_NODESET;
}
/**
* preEvaluate: this method suppresses compile-time evaluation by doing nothing
* @param visitor an expression visitor
*/
public Expression preEvaluate(ExpressionVisitor visitor) {
return this;
}
/**
* Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited
* by an expression in a source tree.
*
* @param pathMap the PathMap to which the expression should be added
* @param pathMapNodeSet
* @return the pathMapNode representing the focus established by this expression, in the case where this
* expression is the first operand of a path expression or filter expression
*/
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet) {
return addDocToPathMap(pathMap, pathMapNodeSet);
}
/**
* Iterate over the contents of the collection
* @param context the dynamic context
* @return an iterator, whose items will always be nodes (typically but not necessarily document nodes)
* @throws XPathException
*/
public SequenceIterator iterate(final XPathContext context) throws XPathException {
String href;
if (getNumberOfArguments() == 0) {
// No arguments supplied: this gets the default collection
href = context.getConfiguration().getDefaultCollection();
} else {
href = argument[0].evaluateItem(context).getStringValue();
}
CollectionURIResolver resolver = context.getConfiguration().getCollectionURIResolver();
SequenceIterator iter;
try {
iter = resolver.resolve(href, expressionBaseURI, context);
} catch (XPathException e) {
e.setLocator(this);
throw e;
}
return getResolverResults(iter, expressionBaseURI, context, this);
}
public static SequenceIterator getResolverResults(
SequenceIterator iter, final String baseURI, final XPathContext context, final SourceLocator locator) {
if (iter == null) {
return EmptyIterator.getInstance();
} else {
ItemMappingFunction imf = new ItemMappingFunction() {
public Item map(Item item) throws XPathException {
if (item instanceof NodeInfo) {
return item;
} else if (item instanceof AnyURIValue) {
return Document.makeDoc(
item.getStringValue(),
baseURI,
context,
locator);
} else {
throw new XPathException("Value returned by CollectionURIResolver must be an anyURI or a NodeInfo");
}
}
};
return new ItemMappingIterator(iter, imf);
}
}
// TODO: provide control over error recovery (etc) through options in the catalog file.
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//