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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2015 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.expr.parser.ExplicitLocation;
import net.sf.saxon.expr.parser.Location;
import net.sf.saxon.ma.arrays.ArrayItem;
import net.sf.saxon.ma.map.MapItem;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.SchemaType;
import net.sf.saxon.type.SimpleType;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.ObjectValue;
/**
* 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 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
private boolean inStartTag = false;
private boolean serializing = false;
/**
* 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(/*@NotNull*/ Receiver nextInChain) {
super(nextInChain.getPipelineConfiguration());
nextReceiver = nextInChain;
previousAtomic = false;
setPipelineConfiguration(nextInChain.getPipelineConfiguration());
}
public void setSystemId(String systemId) {
if (systemId != null && !systemId.equals(this.systemId)) {
this.systemId = systemId;
if (nextReceiver != null) {
nextReceiver.setSystemId(systemId);
}
}
}
public void setPipelineConfiguration(/*@NotNull*/ PipelineConfiguration pipe) {
if (pipelineConfiguration != pipe) {
pipelineConfiguration = pipe;
if (nextReceiver != null) {
nextReceiver.setPipelineConfiguration(pipe);
}
}
}
/**
* Say whether this ComplexContentOutputter is performing serialization
*
* @param serializing true if this class implements the sequence normalization function of the serialization
* spec; false if it is constructing document or element nodes in XSLT or XQuery
*/
public void setSerializing(boolean serializing) {
this.serializing = serializing;
}
/**
* Ask whether this ComplexContentOutputter is performing serialization
*
* @return true if this class implements the sequence normalization function of the serialization
* spec; false if it is constructing document or element nodes in XSLT or XQuery
*/
public boolean isSerializing() {
return serializing;
}
/**
* Get the underlying Receiver (that is, the next one in the pipeline)
*
* @return the underlying Receiver
*/
public Receiver getUnderlyingReceiver() {
return nextReceiver;
}
/**
* Start of event sequence
*/
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
*/
public void close() throws XPathException {
if (nextReceiver != null) {
nextReceiver.close();
}
previousAtomic = false;
}
/**
* Start of a document node.
*/
public void startDocument(int properties) throws XPathException {
if (level == 0) {
nextReceiver.startDocument(properties);
}
if (isDocumentLevel.length - 1 < level) {
boolean[] d2 = new boolean[level * 2];
System.arraycopy(isDocumentLevel, 0, d2, 0, level);
isDocumentLevel = d2;
}
isDocumentLevel[level++] = true;
}
/**
* Notify the end of a document node
*/
public void endDocument() throws XPathException {
level--;
if (level == 0) {
nextReceiver.endDocument();
}
}
/**
* Notify the start of an element
* @param nameCode integer code identifying the name of the element within the name pool.
* @param typeCode integer code identifying the element's type within the name pool.
* @param location
* @param properties bit-significant properties of the element node
*/
public void startElement(NodeName nameCode, SchemaType typeCode, Location location, int properties) throws XPathException {
if (inStartTag) {
startContent();
}
inStartTag = true;
nextReceiver.startElement(nameCode, typeCode, location, properties);
previousAtomic = false;
if (isDocumentLevel.length - 1 < level) {
boolean[] d2 = new boolean[level * 2];
System.arraycopy(isDocumentLevel, 0, d2, 0, level);
isDocumentLevel = d2;
}
isDocumentLevel[level++] = false;
}
/**
* Notify a namespace. Namespaces are notified after the startElement event, and before
* any children for the element. The namespaces that are reported are only required
* to include those that are different from the parent element; however, duplicates may be reported.
* A namespace must not conflict with any namespaces already used for element or attribute names.
*
* @param namespaceBinding the prefix/uri pair
* @throws IllegalStateException: attempt to output a namespace when there is no open element
* start tag
*/
public void namespace(NamespaceBinding namespaceBinding, int properties) throws XPathException {
boolean documentLevel = level == 0 || isDocumentLevel[level - 1];
if (documentLevel || !inStartTag) {
throw NoOpenStartTagException.makeNoOpenStartTagException(
Type.NAMESPACE, namespaceBinding.getPrefix(),
getPipelineConfiguration().getHostLanguage(),
documentLevel, isSerializing(),
ExplicitLocation.UNKNOWN_LOCATION);
}
nextReceiver.namespace(namespaceBinding, properties);
previousAtomic = false;
}
/**
* Notify an attribute. Attributes are notified after the startElement event, and before any
* children. Namespaces and attributes may be intermingled.
*
* @param nameCode The name of the attribute, as held in the name pool
* @param typeCode The type of the attribute, as held in the name pool
* @param locationId
*@param properties Bit significant value. The following bits are defined:
* DISABLE_ESCAPING Disable escaping for this attribute
* NO_SPECIAL_CHARACTERS Attribute value contains no special characters @throws IllegalStateException: attempt to output an attribute when there is no open element
* start tag
*/
public void attribute(NodeName nameCode, SimpleType typeCode, CharSequence value, Location locationId, int properties)
throws XPathException {
boolean documentLevel = level == 0 || isDocumentLevel[level - 1];
if (documentLevel || !inStartTag) {
throw NoOpenStartTagException.makeNoOpenStartTagException(
Type.ATTRIBUTE, nameCode.getDisplayName(),
getPipelineConfiguration().getHostLanguage(),
documentLevel, isSerializing(),
ExplicitLocation.UNKNOWN_LOCATION);
}
nextReceiver.attribute(nameCode, typeCode, value, locationId, properties);
previousAtomic = false;
}
/**
* Notify the start of the content, that is, the completion of all attributes and namespaces.
* Note that the initial receiver of output from XSLT instructions will not receive this event,
* it has to detect it itself. Note that this event is reported for every element even if it has
* no attributes, no namespaces, and no content.
*/
public void startContent() throws XPathException {
inStartTag = false;
nextReceiver.startContent();
previousAtomic = false;
}
/**
* End of element
*/
public void endElement() throws XPathException {
if (inStartTag) {
startContent();
}
nextReceiver.endElement();
previousAtomic = false;
level--;
}
/**
* Character data
*/
public void characters(CharSequence chars, Location locationId, int properties) throws XPathException {
if (chars.length() > 0) {
if (inStartTag) {
startContent();
}
nextReceiver.characters(chars, locationId, properties);
}
previousAtomic = false;
}
/**
* Processing Instruction
*/
public void processingInstruction(String target, CharSequence data, Location locationId, int properties) throws XPathException {
if (inStartTag) {
startContent();
}
nextReceiver.processingInstruction(target, data, locationId, properties);
previousAtomic = false;
}
/**
* Output a comment
*/
public void comment(CharSequence chars, Location locationId, int properties) throws XPathException {
if (inStartTag) {
startContent();
}
nextReceiver.comment(chars, locationId, properties);
previousAtomic = false;
}
/**
* Set the URI for an unparsed entity in the document.
*/
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
*/
public void append(/*@Nullable*/ Item item, Location locationId, int copyNamespaces) throws XPathException {
if (item != null) {
if (item instanceof AtomicValue || item instanceof ObjectValue) {
if (previousAtomic) {
characters(" ", locationId, 0);
}
characters(item.getStringValueCS(), locationId, 0);
previousAtomic = true;
} else if (item instanceof Function) {
String what = "a function item";
if (item instanceof MapItem) {
what = "a map";
} else if (item instanceof ArrayItem) {
what = "an array";
}
throw new XPathException("Cannot add " + what + " to a tree");
} else if (((NodeInfo) item).getNodeKind() == Type.DOCUMENT) {
startDocument(0); // needed to ensure that illegal namespaces or attributes in the content are caught
SequenceIterator iter = ((NodeInfo) item).iterateAxis(AxisInfo.CHILD);
Item it;
while ((it = iter.next()) != null) {
append(it, locationId, copyNamespaces);
}
previousAtomic = false;
endDocument();
} else {
int copyOptions = CopyOptions.TYPE_ANNOTATIONS;
if (copyNamespaces == NodeInfo.LOCAL_NAMESPACES) {
copyOptions |= CopyOptions.LOCAL_NAMESPACES;
} else if (copyNamespaces == NodeInfo.ALL_NAMESPACES) {
copyOptions |= CopyOptions.ALL_NAMESPACES;
}
((NodeInfo) item).copy(this, copyOptions, locationId);
previousAtomic = false;
}
}
}
/**
* 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
*/
public boolean usesTypeAnnotations() {
return nextReceiver.usesTypeAnnotations();
}
}
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