iaik.ixsil.algorithms

Class Transform

java.lang.Object

iaik.ixsil.algorithms.Algorithm

iaik.ixsil.algorithms.Transform

Direct Known Subclasses:

TransformImplBase64Decode, TransformImplCanonicalXML, TransformImplDecryption, TransformImplEnvelopedSignature, TransformImplExclusiveCanonicalXML, TransformImplXPath, TransformImplXPath2, TransformImplXSLT

public abstract class Transform
extends Algorithm

Defines the behaviour of a transform in addition to the standard algorithm's behaviour. A transform takes input data either in form of an octet stream (applicable for arbitrary input) or a XPath node set (applicable only for XML input). The former can be set with the method setInput(InputStream, URI), the latter with the method setInput(NodeList, URI). The result of a transform can either be an octet stream or a XPath node set.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.w3c.dom.NodeList	inputNodeSet_ The XPath node set input data for the algorithm.
protected java.io.InputStream	inputOctetStream_ The octet stream input data for the algorithm.
protected URI	inputURI_ An identifier for the input data for the algorithm.

Fields inherited from class iaik.ixsil.algorithms.Algorithm

uri_

Constructor Summary

Constructors

Constructor and Description
Transform()

Method Summary

Methods

Modifier and Type	Method and Description
static java.util.List	distributeNSDeclarations(org.w3c.dom.Element specElement, boolean skipStylesheet) This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).
void	setInput(java.io.InputStream input, URI inputURI) Sets the data to be processed by the transform as an octet stream.
void	setInput(org.w3c.dom.NodeList input, URI inputURI) Sets the data to be processed by the transform as a XPath node set.
protected static org.w3c.dom.Element	skipStylesheetElem(org.w3c.dom.Element candidate, org.w3c.dom.Element specElement, org.w3c.dom.traversal.NodeIterator allNodes) This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).
abstract java.lang.Object	transform() Computes the result of the transform, according to the implemented algorihtm either as octet stream or as XPath node set.
static void	withdrawDistributedNSDeclarations(org.w3c.dom.Element element, java.util.List addedNSDecls) This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).

Methods inherited from class iaik.ixsil.algorithms.Algorithm

getURI, setParameters, setURI, toElement

Methods inherited from class java.lang.Object

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

Field Detail

inputOctetStream_

protected java.io.InputStream inputOctetStream_

The octet stream input data for the algorithm.

inputNodeSet_

protected org.w3c.dom.NodeList inputNodeSet_

The XPath node set input data for the algorithm.

inputURI_

protected URI inputURI_

An identifier for the input data for the algorithm.

Constructor Detail

Transform

public Transform()

Method Detail

transform

public abstract java.lang.Object transform()
                                    throws AlgorithmException

Computes the result of the transform, according to the implemented algorihtm either as octet stream or as XPath node set. Therefore the result can be an instance of either InputStream or NodeList.

Returns:

the result of computing the transform.

Throws:

AlgorithmException - if computing the transform's result fails for any reason.

setInput

public void setInput(java.io.InputStream input,
            URI inputURI)

Sets the data to be processed by the transform as an octet stream.

Parameters:

input - The octet stream to be processed by the transform. Must not be null.

inputURI - An identifier for the input ressource. Can be used by an implementation to absolutize relative URIs within the input ressource. May be null.

setInput

public void setInput(org.w3c.dom.NodeList input,
            URI inputURI)

Sets the data to be processed by the transform as a XPath node set.

Parameters:

input - The XPath node set to be processed by the transform. Must not be null.

inputURI - An identifier for the input ressource. Can be used by an implementation to absolutize relative URIs within the input ressource. May be null.

distributeNSDeclarations

public static java.util.List distributeNSDeclarations(org.w3c.dom.Element specElement,
                                      boolean skipStylesheet)

This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).

Takes the owner document of the specified DOM element and distributes all namespace declarations (i. e. attributes named xmlns or with a name prefix xmlns:) to all elements of the document. This means, that all namespace declarations which are in scope for a particular element being part of the owner document, will be explicitly set after an invocation of this method.

If the parameter skipStylesheet is true, namespace declarations are not distributed to an element elem if it fulfills all of the following conditions:

• elem's local name is stylesheet or transform.
• elem's namespace is http://www.w3.org/1999/XSL/Transform.
• The element specified in parameter specElement or one of its ancestors is an XML Signature element (dsig:Signature) and elem is a descendant of that XML Signature element as well.

Namepspace declarations are then not distributed to descendents of elem as well.

Parameters:

specElement - An element part of the document to be treated as explained above.

skipStylesheet - See explanation above.

Returns:

a List containing all namespace declarations which have been added to the owner document of the specified element by this method.

skipStylesheetElem

protected static org.w3c.dom.Element skipStylesheetElem(org.w3c.dom.Element candidate,
                                     org.w3c.dom.Element specElement,
                                     org.w3c.dom.traversal.NodeIterator allNodes)

This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).

If all of the following conditions are met, iterate through allNodes and return next element, which is not a descendant of candidate; return null, if there is no such element any more. If one of the conditions is not met, return candidate.

• candidate's local name is stylesheet or transform.
• candidate's namespace is http://www.w3.org/1999/XSL/Transform.
• specElement or one of its ancestors is an XML Signature element (dsig:Signature) and candidate is a descendant of that XML Signature element as well.

Parameters:

candidate - See explanation above.

specElement - See explanation above.

allNodes - See explanation above.

Returns:

See explanation above.

withdrawDistributedNSDeclarations

public static void withdrawDistributedNSDeclarations(org.w3c.dom.Element element,
                                     java.util.List addedNSDecls)

This method is part of a workaround necessary to cope with differences in the tree model of XPath and DOM with respect to namespace declarations (TreeModelWorkaround).

Removes all namespace declarations specified in parameter CaddedNSDecls from the owner document of the specified DOM element. If the owner document of a namespace declaration is not the specified owner document of the specified DOM element, or if the owner element of a namespace declation is not set, the declaration will be ignored.

Parameters:

element - A DOM element part of the DOM document to remove the namespace declarations from. Must not be null.

addedNSDecls - A List containing objects of type org.w3c.dom.Attr representing the namespace declarations to be removed. Must not be null.