org.xmlunit.diff.XPathContext Maven / Gradle / Ivy
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(the "License"); you may not use this file except in compliance with
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distributed under the License is distributed on an "AS IS" BASIS,
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See the License for the specific language governing permissions and
limitations under the License.
*/
package org.xmlunit.diff;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import javax.xml.namespace.QName;
import org.xmlunit.util.Linqy;
import org.xmlunit.util.Nodes;
import org.w3c.dom.Node;
/**
* Helper class that keeps track of the XPath of matched nodes during
* comparison.
*/
public class XPathContext implements Cloneable {
private Deque path = new LinkedList();
private final Map uri2Prefix;
private static final String COMMENT = "comment()";
private static final String PI = "processing-instruction()";
private static final String TEXT = "text()";
private static final String OPEN = "[";
private static final String CLOSE = "]";
private static final String SEP = "/";
private static final String ATTR = "@";
private static final String EMPTY = "";
/**
* Starts with an empty context.
*/
public XPathContext() {
this(null, null);
}
/**
* Starts with the context of a root node.
* @param root the root node
*/
public XPathContext(Node root) {
this(null, root);
}
/**
* Starts with an empty context and a given namespace mapping.
* @param prefix2uri maps from prefix to namespace URI.
*/
public XPathContext(Map prefix2uri) {
this(prefix2uri, null);
}
/**
* Starts with the context of an optional root node and an
* optional namespace mapping.
* @param prefix2uri maps from prefix to namespace URI.
* @param root optional root node that determines the initial XPath
*/
public XPathContext(Map prefix2uri, Node root) {
if (prefix2uri == null) {
this.uri2Prefix = Collections.emptyMap();
} else {
this.uri2Prefix = Collections.unmodifiableMap(invert(prefix2uri));
}
path.addLast(new Level(EMPTY));
if (root != null) {
setChildren(Linqy.singleton(new DOMNodeInfo(root)));
navigateToChild(0);
}
}
/**
* Moves from the current node to the given child node.
* @param index index of child to navigate to
*/
public void navigateToChild(int index) {
path.addLast(path.getLast().children.get(index));
}
/**
* Moves from the current node to the given attribute.
* @param attribute name of attribute to navigate to
*/
public void navigateToAttribute(QName attribute) {
path.addLast(path.getLast().attributes.get(attribute));
}
/**
* Moves back to the parent.
*/
public void navigateToParent() {
path.removeLast();
}
/**
* Adds knowledge about the current node's attributes.
* @param attributes attributes to add
*/
public void addAttributes(Iterable attributes) {
Level current = path.getLast();
for (QName attribute : attributes) {
current.attributes.put(attribute,
new Level(ATTR + getName(attribute)));
}
}
/**
* Adds knowledge about a single attribute of the current node.
* @param attribute attribute to add
*/
public void addAttribute(QName attribute) {
Level current = path.getLast();
current.attributes.put(attribute,
new Level(ATTR + getName(attribute)));
}
/**
* Adds knowledge about the current node's children replacing
* existing knowledge.
* @param children children to add
*/
public void setChildren(Iterable children) {
Level current = path.getLast();
current.children.clear();
appendChildren(children);
}
/**
* Adds knowledge about the current node's children appending to
* the knowledge already present.
* @param children children to add
*/
public void appendChildren(Iterable children) {
Level current = path.getLast();
int comments, pis, texts;
comments = pis = texts = 0;
Map elements = new HashMap();
for (Level l : current.children) {
String childName = l.expression;
if (childName.startsWith(COMMENT)) {
comments++;
} else if (childName.startsWith(PI)) {
pis++;
} else if (childName.startsWith(TEXT)) {
texts++;
} else {
childName = childName.substring(0, childName.indexOf(OPEN));
add1OrIncrement(childName, elements);
}
}
for (NodeInfo child : children) {
Level l;
switch (child.getType()) {
case Node.COMMENT_NODE:
l = new Level(COMMENT + OPEN + (++comments) + CLOSE);
break;
case Node.PROCESSING_INSTRUCTION_NODE:
l = new Level(PI + OPEN + (++pis) + CLOSE);
break;
case Node.CDATA_SECTION_NODE:
case Node.TEXT_NODE:
l = new Level(TEXT + OPEN + (++texts) + CLOSE);
break;
case Node.ELEMENT_NODE:
String name = getName(child.getName());
l = new Level(name + OPEN + add1OrIncrement(name, elements)
+ CLOSE);
break;
default:
// more or less ignore
// FIXME: is this a good thing?
l = new Level(EMPTY);
break;
}
current.children.add(l);
}
}
/**
* Stringifies the XPath of the current node.
* @return current XPath
*/
public String getXPath() {
return getXPath(path.descendingIterator());
}
/**
* Stringifies the XPath of the current node's parent.
* @return parent's XPath
*/
public String getParentXPath() {
Iterator levelIterator = path.descendingIterator();
if (levelIterator.hasNext()) {
levelIterator.next();
}
return getXPath(levelIterator);
}
/**
* Creates a deep copy of this XPathContext.
*/
@Override
public XPathContext clone() {
try {
XPathContext c = (XPathContext) super.clone();
c.path = new LinkedList();
for (Level l: path) {
c.path.addLast(l.clone());
}
return c;
} catch (CloneNotSupportedException e) {
// impossible
throw new RuntimeException("XPathContext cannot be cloned?", e);
}
}
private String getXPath(Iterator dIterator) {
if (!dIterator.hasNext()) {
return EMPTY;
}
Level l = dIterator.next();
if (null == l.xpath) {
String previous = getXPath(dIterator);
if (!SEP.equals(previous)) {
previous += SEP;
}
l.xpath = previous + l.expression;
}
return l.xpath;
}
private String getName(QName name) {
String ns = name.getNamespaceURI();
String p = null;
if (ns != null) {
p = uri2Prefix.get(ns);
}
return (p == null ? EMPTY : p + ":") + name.getLocalPart();
}
/**
* Increments the value name maps to or adds 1 as value if name
* isn't present inside the map.
*
* @return the new mapping for name
*/
private static int add1OrIncrement(String name, Map map) {
Integer old = map.get(name);
int index = old == null ? 1 : old.intValue() + 1;
map.put(name, Integer.valueOf(index));
return index;
}
private static class Level implements Cloneable {
private final String expression;
private List children = new ArrayList();
private Map attributes = new HashMap();
private String xpath;
private Level(String expression) {
this.expression = expression;
}
@Override
public Level clone() {
try {
Level l = (Level) super.clone();
l.children = new ArrayList(children.size());
for (Level c : children) {
l.children.add(c.clone());
}
l.attributes = new HashMap(attributes.size());
for (Map.Entry e : attributes.entrySet()) {
l.attributes.put(e.getKey(), e.getValue().clone());
}
return l;
} catch (CloneNotSupportedException e) {
// impossible
throw new RuntimeException("Level cannot be cloned?", e);
}
}
}
/**
* Representation of a node used by {@link XPathContext}.
*/
public interface NodeInfo {
/**
* @return QName of the node
*/
QName getName();
/**
* @return node type
*/
short getType();
}
/**
* DOM based implementation of {@link NodeInfo}.
*/
public static final class DOMNodeInfo implements NodeInfo {
private final QName name;
private final short type;
/**
* @param n node to capture information of
*/
public DOMNodeInfo(Node n) {
name = Nodes.getQName(n);
type = n.getNodeType();
}
@Override
public QName getName() { return name; }
@Override
public short getType() { return type; }
}
private static Map invert(Map m) {
Map inverted = new HashMap();
for (Map.Entry entry : m.entrySet()) {
inverted.put(entry.getValue(), entry.getKey());
}
return inverted;
}
}
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