XSLT and XML Document Transforming

XSLT is a language that is used for transforming the XML documents from one form to the other. It is a part of the eXtensible Style sheet language (XSL). XSLT allows you to transform data of an XML document to other forms such as WML, HTML etc., The transformation expressed in a XSLT is called as a StyleSheet.

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XSLT defines certain rules to transform the source tree into a result tree. Associating the patterns with the templates does this transformation. The elements in the source tree are matched against the patterns. The result tree is different from the source tree. The structure of the source tree is completely different from the structure of the result tree.

XSLT uses the Xpath Queries for generating text, and processing the elements. XSLT processors must make use of the XML namespaces to recognize the elements and the attributes in this namespaces. The elements in the XSLT namespace are recognized only by the Style Sheet and not in the source document. XSLT enables inter operability. XSLT includes a construct that allows us to find the structures found in the source document. One important advantage of XSLT is that the users donot have the burden of implementing numerous algorithms to present data.

XSLT Style sheets are often called as XSL Transformations because they can be used even in areas that are not related to Style Sheets.XSLT can do the following:

It can add or remove new elements to the Output file.
It can rearrange and sort elements.
It can make decisions regarding the display of elements and a lot more.

XSLT provides a lot of functions:

current( ) : Returns the current node
document( ) : Used for accessing a node in an external document
element-available( ) : Checks whether the XSLT processor supports the element specified.
format number( ) : Converts a number into a string.
function available( ) : Checks whether the XSLT processor supports the function specified.
generate id( ) : Returns a string value that uniquely identifies a node.
key( ) : Returns the node set specified by the element.
system property( ) : Returns the value of system properties.
Unparsed-entity-uri( ) : Returns the URI of an Unparsed entity.

XSLT provides two ways to combine Style Sheets:

An INCLUSION mechanism that allows Style Sheets to be combined without making any change to the rules of the Style Sheets combined.

An IMPORT mechanism that allows Style Sheets to over ride each other.