org.eclipse.jet
Class XPathContextExtender

java.lang.Object
  org.eclipse.jet.XPathContextExtender

All Implemented Interfaces:

XPathVariableResolver

public final class XPathContextExtender
extends java.lang.Object
implements XPathVariableResolver

Context Extender that understands XPath processing.

Constructor Summary

XPathContextExtender(JET2Context context)
Deprecated. Use getInstance(JET2Context). This method will be made private in the near future.

Method Summary

void	addCustomFunctions(XPathFunctionMetaData[] functionData) Add the passed list of XPath function definitions to the XPath processor.
java.lang.Object	addElement(java.lang.Object parent, java.lang.String name)
java.lang.Object	addTextElement(java.lang.Object parentElement, java.lang.String name, java.lang.String bodyContent) Create a new text (simple) element whose content is set to bodyContent.
java.lang.Object	addTextElement(java.lang.Object parentElement, java.lang.String name, java.lang.String bodyContent, boolean asCData) Create a new text (simple) element whose content is set to bodyContent.
java.lang.Object	copyElement(java.lang.Object srcElement, java.lang.Object tgtParent, java.lang.String name, boolean recursive) Copy srcElement as a new element with the specified name under tgtParent.
protected java.lang.Object	createExtendedData(JET2Context context)
java.lang.Object	currentXPathContextObject() Return the current XPath context object.
java.lang.Object	getAttributeValue(java.lang.Object element, java.lang.String attributeName) Return the value of the named attribute on the passed element.
java.lang.String	getContent(java.lang.Object object) Return the string value of the passed object.
static XPathContextExtender	getInstance(JET2Context context) Factory method for XPathContextExtenders
java.lang.Object	popXPathContextObject() Restore the previous XPath context object.
void	pushXPathContextObject(java.lang.Object contextObject) Push a new XPath context object.
void	removeAttribute(java.lang.Object element, java.lang.String attributeName) Remove the named attribute from the specified element.
void	removeElement(java.lang.Object element)
java.lang.Object[]	resolve(java.lang.Object xpathContextObject, java.lang.String selectXPath) Resolve an XPath expression into an array of Objects.
java.lang.Object[]	resolve(java.lang.String selectXPath) Resolve an XPath expression into an array of Objects.
java.lang.Object	resolveAsObject(java.lang.Object contextObject, java.lang.String selectXPath) Resolve the XPath expression, returning an object.
java.lang.Object	resolveAsObject(java.lang.String selectXPath) Resolve the XPath expression, returning an object.
java.lang.String	resolveAsString(java.lang.Object xpathContextObject, java.lang.String selectXPath) Resolve the given XPath expression as a string value.
java.lang.String	resolveAsString(java.lang.String selectXPath) Resolve the given XPath expression as a string value.
java.lang.String	resolveDynamic(java.lang.String value) Resolve dynamic XPath expressions {...} within the pass value
static java.lang.String	resolveDynamic(java.lang.String value, JET2Context context)
java.lang.Object	resolveSingle(java.lang.Object xpathContextObject, java.lang.String selectXPath) Resolve an XPath expression to a single object.
java.lang.Object	resolveSingle(java.lang.String selectXPath) Resolve an XPath expression to a single object.
boolean	resolveTest(java.lang.Object xpathContext, java.lang.String testXPath) Resolve an xpath expression as a boolean result according to the XPath rules.
boolean	resolveTest(java.lang.String textXPath) Resolve an xpath expression as a boolean result according to the XPath rules.
java.lang.Object	resolveVariable(java.lang.String name)
boolean	setAttribute(java.lang.Object element, java.lang.String name, java.lang.String bodyContent)

Methods inherited from class java.lang.Object

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

Constructor Detail

XPathContextExtender

public XPathContextExtender(JET2Context context)

Deprecated. Use getInstance(JET2Context). This method will be made private in the near future.

Parameters:

context -

Method Detail

getInstance

public static XPathContextExtender getInstance(JET2Context context)

Factory method for XPathContextExtenders

Parameters:

context - the JET2Context that is extended

Returns:

an XPathContextExtender

createExtendedData

protected java.lang.Object createExtendedData(JET2Context context)

resolveVariable

public java.lang.Object resolveVariable(java.lang.String name)

Specified by:

resolveVariable in interface XPathVariableResolver

resolveAsString

public java.lang.String resolveAsString(java.lang.Object xpathContextObject,
                                        java.lang.String selectXPath)
                                 throws JET2TagException

Resolve the given XPath expression as a string value. Note that if the XPath expression returns an empty Node set, this method returns null

Parameters:

xpathContextObject - the xpath context

selectXPath - the XPath expression

Returns:

the string value of the XPath expression, or null if the expression resulted in an empty node set.

Throws:

JET2TagException - if an error occurs during expression evaluation

resolveAsString

public java.lang.String resolveAsString(java.lang.String selectXPath)
                                 throws JET2TagException

Resolve the given XPath expression as a string value. Note that if the XPath expression returns an empty Node set, this method returns null. This is a convenience implementation of:

 resolveAsString(currentXPathContextObject(), selectXPath)
 

Parameters:

selectXPath - the XPath expression

Returns:

the string value of the XPath expression, or null if the expression resulted in an empty node set.

Throws:

JET2TagException - if an error occurs during expression evaluation

Since:

1.0

See Also:

resolveAsString(Object, String)

resolveSingle

public java.lang.Object resolveSingle(java.lang.Object xpathContextObject,
                                      java.lang.String selectXPath)
                               throws JET2TagException

Resolve an XPath expression to a single object. If the Xpath expression returns a collection, then return the first element in the collection, or null if that colleciton is empty. Otherwise, the result of the XPath expression is returned.

Parameters:

xpathContextObject - the context object used to resolve relative XPath expressions

selectXPath - the Xpath expression

Returns:

an Object or null

Throws:

JET2TagException - if an XPath error occurs.

resolveSingle

public java.lang.Object resolveSingle(java.lang.String selectXPath)
                               throws JET2TagException

Resolve an XPath expression to a single object. This is a convenience implementation of:

 resolveSingle(currentXPathContextObject(), selectXPath)
 

Parameters:

selectXPath - the Xpath expression

Returns:

an Object or null

Throws:

JET2TagException - if an XPath error occurs.

Since:

1.0

See Also:

resolveSingle(Object, String)

currentXPathContextObject

public java.lang.Object currentXPathContextObject()

Return the current XPath context object. If no context object has been specified via {pushXPathContextObject(Object), then value of JET2Context.getSource() is returned

Returns:

the XPath context object

pushXPathContextObject

public void pushXPathContextObject(java.lang.Object contextObject)

Push a new XPath context object. The XPath context object is used to resolve relative XPath expressions.

Parameters:

contextObject - the object that will be the new XPath context object

Since:

1.0

See Also:

currentXPathContextObject(), popXPathContextObject()

popXPathContextObject

public java.lang.Object popXPathContextObject()

Restore the previous XPath context object.

Returns:

the XPath context object that was just removed

Throws:

java.util.EmptyStackException - if there is no prior XPath context to restore.

Since:

1.0

See Also:

currentXPathContextObject(), pushXPathContextObject(Object)

resolve

public java.lang.Object[] resolve(java.lang.Object xpathContextObject,
                                  java.lang.String selectXPath)
                           throws JET2TagException

Resolve an XPath expression into an array of Objects.

Parameters:

xpathContextObject - the context object for relative Xpath expressions

selectXPath - the XPath expression

Returns:

a possibly empty array of objects resolved by the expression

Throws:

JET2TagException - if an error in the XPath expression occurs

resolve

public java.lang.Object[] resolve(java.lang.String selectXPath)
                           throws JET2TagException

Resolve an XPath expression into an array of Objects. This method is a convenience implementation of:

 resolve(currentXPathContextObject(), selectXPath)
 

Parameters:

selectXPath - selectXPath the XPath expression

Returns:

a possibly empty array of objects resolved by the expression

Throws:

JET2TagException - if an error in the XPath expression occurs

Since:

1.0

resolveTest

public boolean resolveTest(java.lang.Object xpathContext,
                           java.lang.String testXPath)
                    throws JET2TagException

Resolve an xpath expression as a boolean result according to the XPath rules.

See the documentation of the XPathboolean function for complete details on how XPath results are converted to boolean values.

Parameters:

xpathContext - the XPath context object

testXPath - the XPath expression

Returns:

true or false

Throws:

JET2TagException - if an error occurs in evaluating the expression.

resolveTest

public boolean resolveTest(java.lang.String textXPath)
                    throws JET2TagException

Resolve an xpath expression as a boolean result according to the XPath rules. This method is a convenience implementation of:

 resolveTest(currentXPathContextObject(), textXPath)
 

Parameters:

testXPath - the XPath expression

Returns:

true or false

Throws:

JET2TagException - if an error occurs in evaluating the expression.

Since:

1.0

See Also:

resolveTest(Object, String)

setAttribute

public boolean setAttribute(java.lang.Object element,
                            java.lang.String name,
                            java.lang.String bodyContent)
                     throws JET2TagException

Throws:

JET2TagException

resolveDynamic

public java.lang.String resolveDynamic(java.lang.String value)
                                throws JET2TagException

Resolve dynamic XPath expressions {...} within the pass value

Parameters:

value - a string containing zero or more dynamic xpath expressions

Returns:

the string with all dynamic xpath expressions resolved

Throws:

JET2TagException - if an Xpath evaluation error occurs

resolveDynamic

public static java.lang.String resolveDynamic(java.lang.String value,
                                              JET2Context context)
                                       throws JET2TagException

Throws:

JET2TagException

addElement

public java.lang.Object addElement(java.lang.Object parent,
                                   java.lang.String name)
                            throws JET2TagException

Throws:

JET2TagException

removeElement

public void removeElement(java.lang.Object element)
                   throws JET2TagException

Throws:

JET2TagException

copyElement

public java.lang.Object copyElement(java.lang.Object srcElement,
                                    java.lang.Object tgtParent,
                                    java.lang.String name,
                                    boolean recursive)
                             throws JET2TagException

Copy srcElement as a new element with the specified name under tgtParent. If recursive is true, then all the contained children of srcElement are copied, otherwise, only the element and its attributes are copied.

Parameters:

srcElement - the element to copy

tgtParent - the parent element that will contain the copy

name - the name of the copied element

recursive - true if contained chidren are to be copied, too.

Returns:

the newly copied element

Throws:

JET2TagException - an error occurs

addTextElement

public java.lang.Object addTextElement(java.lang.Object parentElement,
                                       java.lang.String name,
                                       java.lang.String bodyContent)
                                throws JET2TagException

Create a new text (simple) element whose content is set to bodyContent.

Parameters:

parentElement - the parent of the new element.

name - the name of the new element.

bodyContent - the content.

Returns:

the new Element.

Throws:

JET2TagException - if the element cannot be added.

addTextElement

public java.lang.Object addTextElement(java.lang.Object parentElement,
                                       java.lang.String name,
                                       java.lang.String bodyContent,
                                       boolean asCData)
                                throws JET2TagException

Create a new text (simple) element whose content is set to bodyContent.

Parameters:

parentElement - the parent of the new element.

name - the name of the new element.

bodyContent - the content.

asCData - if true, create the element as a CDATA section, of possible

Returns:

the new element.

Throws:

JET2TagException - if the element cannot be added.

resolveAsObject

public java.lang.Object resolveAsObject(java.lang.Object contextObject,
                                        java.lang.String selectXPath)
                                 throws JET2TagException

Resolve the XPath expression, returning an object. Unlike the other resolve methods, this method performs no type conversions on the XPath results.

Parameters:

contextObject - the context object to which the XPath expression is relative.

selectXPath - the XPath expression

Returns:

the result of the expression evaluation.

Throws:

JET2TagException - if an error occurs.

resolveAsObject

public java.lang.Object resolveAsObject(java.lang.String selectXPath)
                                 throws JET2TagException

Resolve the XPath expression, returning an object. Unlike the other resolve methods, this method performs no type conversions on the XPath results. This is a convenience implementation of:

 resolveAsObject(currentXPathContextObject(), selectXPath);
 

Parameters:

selectXPath - the XPath expression

Returns:

the result of the expression evaluation.

Throws:

JET2TagException - if an error occurs.

Since:

1.0

See Also:

resolveAsObject(Object, String)

getAttributeValue

public java.lang.Object getAttributeValue(java.lang.Object element,
                                          java.lang.String attributeName)
                                   throws JET2TagException

Return the value of the named attribute on the passed element.

Parameters:

element - the element containing the attribute

attributeName - the attribute name

Returns:

the attribute value

Throws:

JET2TagException

removeAttribute

public void removeAttribute(java.lang.Object element,
                            java.lang.String attributeName)
                     throws JET2TagException

Remove the named attribute from the specified element.

Parameters:

element - the element containing the attribute

attributeName - the attribute to remove

Throws:

JET2TagException - if the attribute cannot be removed (because it is required), or if element is not a recognized element.

getContent

public java.lang.String getContent(java.lang.Object object)
                            throws JET2TagException

Return the string value of the passed object. This equivalent to calling the XPath string() function on the passed object.

Parameters:

object - the object to examine.

Returns:

the string value.

Throws:

JET2TagException - if an error occurs.

addCustomFunctions

public void addCustomFunctions(XPathFunctionMetaData[] functionData)

Add the passed list of XPath function definitions to the XPath processor.

Parameters:

functionData - possible empty array of XPathFunctionMetaData instances.