com.eibus.xml.xpath

Class XPathMetaInfo

java.lang.Object

com.eibus.xml.xpath.XPathMetaInfo

public class XPathMetaInfo
extends java.lang.Object

This class provides a means to give additional inputs the XPath evaluation as "metainfo".For example, specifying variable binding, namespace bindings,registering attributes, etc.

Constructor Summary

Constructors

Constructor and Description
XPathMetaInfo() Creates an instance of XPathMetaInfo object.

Method Summary

Modifier and Type	Method and Description
void	addNamespaceBinding(java.lang.String sPrefix, java.lang.String sURI) Binds a prefix to the specific URI in the document.
void	addVarBinding(java.lang.String sVarName, XPathResult oXpathResult) Binds a result to a variable.
void	delete() Deletes native handle of the XPathMetaInfo object explicitly.
protected void	finalize()
java.lang.String	getNamespaceBinding(java.lang.String sPrefix)
protected long	getNativeHandle()
void	registerIDAttribute(java.lang.String sAttr) Registers an ID Attribute.This refers to an attribute that will have unique value in the document.That is, no two elements in the document can have the same unique id.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XPathMetaInfo

public XPathMetaInfo()

Creates an instance of XPathMetaInfo object. Throws IllegalOperationException in case of any error.

Method Detail

registerIDAttribute

public void registerIDAttribute(java.lang.String sAttr)

Registers an ID Attribute.This refers to an attribute that will have unique value in the document.That is, no two elements in the document can have the same unique id. Search can be based on this attribute using the XPath core library function id().
Note: Since the input to the id() function does not contain location steps, selectNodes() method must not be used to evaluate this expression.Instead evaluate() method must be used.

Parameters:

sAttr - The attribute that is to be registered.

Example:

 <code>
 Document oDocument = new Document();
 int iXml;
 try {
        iXml = oDocument
                        .load("<root><table attr=\"abc\">text1</table><table attr=\"xyz\">text2</table></root>"
                                        .getBytes());
        XPathMetaInfo m = new XPathMetaInfo();
        m.registerIDAttribute("attr");
        String str1 = "\"abc\"";
        XPath x = XPath.getXPathInstance("id(" + str1 + ")");
        XPathResult xRes = x.evaluate(iXml, m);
        NodeSet n = xRes.removeNodeSetFromResult();
        int res[] = n.getElementNodes();
        assertEquals("<table attr=\"abc\">text1</table>", Node.writeToString(
                        res[0], false));
        str1 = "\"xyz\"";
        x = XPath.getXPathInstance("id(" + str1 + ")");
        xRes = x.evaluate(iXml, m);
        n = xRes.removeNodeSetFromResult();
        res = n.getElementNodes();
        assertEquals("<table attr=\"xyz\">text2</table>", Node.writeToString(
                        res[0], false));
 } catch (XMLException e) {
        e.printStackTrace();
 }
 </code>
 

addVarBinding

public void addVarBinding(java.lang.String sVarName,
                          XPathResult oXpathResult)

Binds a result to a variable.

Parameters:

sVarName - Variable to be bound. eg: var => $var is bound

oXpathResult - The XPathResult object

Example:

 <code>
 Document doc = new Document();
 int iXml;
 try {
        iXml = doc
                        .load("<root><table attr=\"abc\">text</table><chair attr=\"abc\"/></root>"
                                        .getBytes());
        XPathMetaInfo m = new XPathMetaInfo();
        XPathResult xRes = XPathResult.getInstance("abc");
        XPath x = XPath.getXPathInstance("//root/*[@attr=$var]");
        m.addVarBinding("var", xRes);
        XPathResult xResult = x.evaluate(iXml, m);
        NodeSet nSet = xResult.removeNodeSetFromResult();
        assertEquals(2, nSet.size());
 } catch (XMLException e) {
        e.printStackTrace();
 }
 </code>
 

addNamespaceBinding

public void addNamespaceBinding(java.lang.String sPrefix,
                                java.lang.String sURI)

Binds a prefix to the specific URI in the document.

Parameters:

sPrefix - - prefix string

sURI - - URI to be bound

Example:

 <code>
 Document oDocument = new Document();
 int iXml;
 try {
        XPathMetaInfo meta = new XPathMetaInfo();
        meta.addNamespaceBinding("html4", "http://www.w3.org/TR/html4");
        iXml = oDocument
                        .load("<root xmlns:h=\"http://www.w3.org/TR/html4\" ><h:table attr1=\"abc\">text</h:table><chair/></root>"
                                        .getBytes());
        XPath oXPath0 = XPath.getXPathInstance("string(//root/html4:table)");
        XPathResult res = oXPath0.evaluate(iXml);
        assertEquals(XPathResult.XPATH_STRING, res.getType());
 } catch (XMLException e) {
        e.printStackTrace();
 }
 </code>
 

getNamespaceBinding

public java.lang.String getNamespaceBinding(java.lang.String sPrefix)

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

delete

public void delete()

Deletes native handle of the XPathMetaInfo object explicitly.

Example:

 <code>
 Document oDocument = new Document();
 int iXml;
 try {
        XPathMetaInfo meta = new XPathMetaInfo();
        meta.addNamespaceBinding("html4", "http://www.w3.org/TR/html4");
        iXml = oDocument
                        .load("<root xmlns:h=\"http://www.w3.org/TR/html4\" ><h:table attr1=\"abc\">text</h:table><chair/></root>"
                                        .getBytes());
        XPath oXPath0 = XPath.getXPathInstance("string(//root/html4:table)");
        XPathResult res = oXPath0.evaluate(iXml);
        assertEquals(XPathResult.XPATH_STRING, res.getType());
        meta.delete();
 } catch (XMLException e) {
        e.printStackTrace();
 }
 </code>
 

getNativeHandle

protected long getNativeHandle()