net.sf.saxon.event.TreeReceiver Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of Saxon-HE Show documentation
Show all versions of Saxon-HE Show documentation
The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2023 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.event;
import net.sf.saxon.om.*;
import net.sf.saxon.s9api.Location;
import net.sf.saxon.str.UnicodeString;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.SchemaType;
import java.util.Arrays;
/**
* A TreeReceiver acts as a bridge between a SequenceReceiver, which can receive
* events for constructing any kind of sequence, and an ordinary Receiver, which
* only handles events relating to the building of trees. To do this, it has to
* process any items added to the sequence using the append() interface; all other
* events are passed through unchanged.
* If atomic items are appended to the sequence, then adjacent atomic items are
* turned in to a text node by converting them to strings and adding a single space
* as a separator.
* If a document node is appended to the sequence, then the document node is ignored
* and its children are appended to the sequence.
* If any other node is appended to the sequence, then it is pushed to the result
* as a sequence of Receiver events, which may involve walking recursively through the
* contents of a tree.
*/
public class TreeReceiver extends SequenceReceiver {
private final Receiver nextReceiver;
private int level = 0;
private boolean[] isDocumentLevel = new boolean[20];
// The sequence of events can include startElement/endElement pairs or startDocument/endDocument
// pairs at any level. A startDocument/endDocument pair is essentially ignored except at the
// outermost level, except that a namespace or attribute node cannot be sent when we're at a
// document level. See for example schema90963-err.xsl
/**
* Create a TreeReceiver
*
* @param nextInChain the receiver to which events will be directed, after
* expanding append events into more primitive tree-based events
*/
public TreeReceiver(Receiver nextInChain) {
super(nextInChain.getPipelineConfiguration());
nextReceiver = nextInChain;
previousAtomic = false;
setPipelineConfiguration(nextInChain.getPipelineConfiguration());
}
@Override
public void setSystemId(String systemId) {
if (systemId != null && !systemId.equals(this.systemId)) {
this.systemId = systemId;
if (nextReceiver != null) {
nextReceiver.setSystemId(systemId);
}
}
}
@Override
public void setPipelineConfiguration(/*@NotNull*/ PipelineConfiguration pipe) {
if (pipelineConfiguration != pipe) {
pipelineConfiguration = pipe;
if (nextReceiver != null) {
nextReceiver.setPipelineConfiguration(pipe);
}
}
}
/**
* Get the underlying Receiver (that is, the next one in the pipeline)
*
* @return the underlying Receiver
*/
public Receiver getNextReceiver() {
return nextReceiver;
}
/**
* Start of event sequence
*/
@Override
public void open() throws XPathException {
if (nextReceiver == null) {
throw new IllegalStateException("TreeReceiver.open(): no underlying receiver provided");
}
nextReceiver.open();
previousAtomic = false;
}
/**
* End of event sequence
*/
@Override
public void close() throws XPathException {
if (nextReceiver != null) {
nextReceiver.close();
}
previousAtomic = false;
}
/**
* Start of a document node.
*/
@Override
public void startDocument(int properties) throws XPathException {
if (level == 0) {
nextReceiver.startDocument(properties);
}
if (isDocumentLevel.length - 1 < level) {
isDocumentLevel = Arrays.copyOf(isDocumentLevel, level * 2);
}
isDocumentLevel[level++] = true;
}
/**
* Notify the end of a document node
*/
@Override
public void endDocument() throws XPathException {
level--;
if (level == 0) {
nextReceiver.endDocument();
}
}
/**
* Notify the start of an element
*/
@Override
public void startElement(NodeName elemName, SchemaType type,
AttributeMap attributes, NamespaceMap namespaces,
Location location, int properties)
throws XPathException {
nextReceiver.startElement(elemName, type, attributes, namespaces, location, properties);
previousAtomic = false;
if (isDocumentLevel.length - 1 < level) {
isDocumentLevel = Arrays.copyOf(isDocumentLevel, level * 2);
}
isDocumentLevel[level++] = false;
}
/**
* End of element
*/
@Override
public void endElement() throws XPathException {
nextReceiver.endElement();
previousAtomic = false;
level--;
}
/**
* Character data
*/
@Override
public void characters(UnicodeString chars, Location locationId, int properties) throws XPathException {
if (!chars.isEmpty()) {
nextReceiver.characters(chars, locationId, properties);
}
previousAtomic = false;
}
/**
* Processing Instruction
*/
@Override
public void processingInstruction(String target, UnicodeString data, Location locationId, int properties) throws XPathException {
nextReceiver.processingInstruction(target, data, locationId, properties);
previousAtomic = false;
}
/**
* Output a comment
*/
@Override
public void comment(UnicodeString chars, Location locationId, int properties) throws XPathException {
nextReceiver.comment(chars, locationId, properties);
previousAtomic = false;
}
/**
* Set the URI for an unparsed entity in the document.
*/
@Override
public void setUnparsedEntity(String name, String uri, String publicId) throws XPathException {
nextReceiver.setUnparsedEntity(name, uri, publicId);
}
/**
* Append an arbitrary item (node or atomic value) to the output
*/
@Override
public void append(/*@Nullable*/ Item item, Location locationId, int copyNamespaces) throws XPathException {
decompose(item, locationId, copyNamespaces);
}
/**
* Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations
* supplied on element and attribute events
*
* @return true if the Receiver makes any use of this information. If false, the caller
* may supply untyped nodes instead of supplying the type annotation
*/
@Override
public boolean usesTypeAnnotations() {
return nextReceiver.usesTypeAnnotations();
}
}