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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.functions;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.expr.parser.PathMap;
import net.sf.saxon.lib.CollectionURIResolver;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.iter.EmptyIterator;
import net.sf.saxon.value.AnyURIValue;
import javax.xml.transform.Source;
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 net.sf.saxon.lib.StandardCollectionURIResolver}
*/
public class Collection extends SystemFunctionCall implements Callable {
/**
* URI representing a collection that is always empty, regardless of any collection URI resolver
*/
public static String EMPTY_COLLECTION = "http://saxon.sf.net/collection/empty";
/*@Nullable*/
private String expressionBaseURI = null;
public String getStaticBaseURI() {
return expressionBaseURI;
}
public void checkArguments(/*@NotNull*/ ExpressionVisitor visitor) throws XPathException {
if (expressionBaseURI == null) {
super.checkArguments(visitor);
expressionBaseURI = visitor.getStaticContext().getBaseURI();
}
}
public int computeSpecialProperties() {
// See redmine bug 1652. We cannot assume that the nodes will be in document order because we can't assume
// they will all be "new" documents. We can't even assume that they will be distinct.
return (super.computeSpecialProperties() & ~StaticProperty.NON_CREATIVE) | 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 the PathMapNodeSet to which the paths embodied in this expression should be added
* @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
*/
/*@NotNull*/
public SequenceIterator- iterate(final XPathContext context) throws XPathException {
String href;
if (getNumberOfArguments() == 0) {
// No arguments supplied: this gets the default collection
href = context.getController().getDefaultCollection();
} else {
Item arg = argument[0].evaluateItem(context);
if (arg == null) {
href = context.getController().getDefaultCollection();
} else {
href = arg.getStringValue();
}
}
if (EMPTY_COLLECTION.equals(href)) {
return EmptyIterator.emptyIterator();
}
CollectionURIResolver resolver = context.getConfiguration().getCollectionURIResolver();
SequenceIterator iter;
try {
iter = resolver.resolve(href, expressionBaseURI, context);
} catch (XPathException e) {
e.setLocator(this);
if (e.getErrorCodeQName() == null) {
e.setErrorCode("FODC0002");
}
throw e;
}
return getResolverResults(iter, expressionBaseURI, context, this);
}
/**
* Return the results of iterating over the results returned by the CollectionURIResolver.
*
Note, this method is called by generated code
*
* @param iter iterator over the results of the CollectionURIResolver
* @param baseURI the base URI
* @param context the dynamic context
* @param locator location of the instruction
* @return an iterator over the documents in the collection.
*/
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 mapItem(Item item) throws XPathException {
if (item instanceof NodeInfo) {
return item;
} else if (item instanceof AnyURIValue) {
return DocumentFn.makeDoc(
item.getStringValue(),
baseURI,
context,
locator);
} else if (item instanceof Source) {
return context.getConfiguration().buildDocument(((Source) item));
} else {
throw new XPathException("Value returned by CollectionURIResolver must be a Source or an anyURI");
}
}
};
return new ItemMappingIterator(iter, imf);
}
}
public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException {
String href;
if (getNumberOfArguments() == 0) {
// No arguments supplied: this gets the default collection
href = context.getConfiguration().getDefaultCollection();
} else {
Item arg = arguments[0].head();
if (arg == null) {
href = context.getConfiguration().getDefaultCollection();
} else {
href = arg.getStringValue();
}
}
CollectionURIResolver resolver = context.getConfiguration().getCollectionURIResolver();
SequenceIterator iter;
try {
iter = resolver.resolve(href, expressionBaseURI, context);
} catch (XPathException e) {
e.setLocator(this);
throw e;
}
return SequenceTool.toLazySequence(getResolverResults(iter, expressionBaseURI, context, this));
}
// TODO: provide control over error recovery (etc) through options in the catalog file.
}