Xpath manipulation

Afin de bien maniupuler XPATH dans la Soa Suite je vous engage à bien connaitre ces quelques astuces:


Selecting Nodes
XPath uses path expressions to select nodes in an XML document. The node is selected by following a path or steps. The most useful path expressions are listed below:
Expression
Description
nodename
Selects all child nodes of the named node
/
Selects from the root node
//
Selects nodes in the document from the current node that match the selection no matter where they are
.
Selects the current node
..
Selects the parent of the current node
@
Selects attributes
In the table below we have listed some path expressions and the result of the expressions:
Path Expression
Result
bookstore
Selects all the child nodes of the bookstore element
/bookstore
Selects the root element bookstore
Note: If the path starts with a slash ( / ) it always represents an absolute path to an element!
bookstore/book
Selects all book elements that are children of bookstore
//book
Selects all book elements no matter where they are in the document
bookstore//book
Selects all book elements that are descendant of the bookstore element, no matter where they are under the bookstore element
//@lang
Selects all attributes that are named lang
Predicates
Predicates are used to find a specific node or a node that contains a specific value.
Predicates are always embedded in square brackets.
In the table below we have listed some path expressions with predicates and the result of the expressions:
Path Expression
Result
/bookstore/book[1]
Selects the first book element that is the child of the bookstore element.
Note: IE5 and later has implemented that [0] should be the first node, but according to the W3C standard it should have been [1]!!
/bookstore/book[last()]
Selects the last book element that is the child of the bookstore element
/bookstore/book[last()-1]
Selects the last but one book element that is the child of the bookstore element
/bookstore/book[position()<3]
Selects the first two book elements that are children of the bookstore element
//title[@lang]
Selects all the title elements that have an attribute named lang
//title[@lang='eng']
Selects all the title elements that have an attribute named lang with a value of 'eng'
/bookstore/book[price>35.00]
Selects all the book elements of the bookstore element that have a price element with a value greater than 35.00
/bookstore/book[price>35.00]/title
Selects all the title elements of the book elements of the bookstore element that have a price element with a value greater than 35.00
Selecting Unknown Nodes
XPath wildcards can be used to select unknown XML elements.
Wildcard
Description
*
Matches any element node
@*
Matches any attribute node
node()
Matches any node of any kind
In the table below we have listed some path expressions and the result of the expressions:
Path Expression
Result
/bookstore/*
Selects all the child nodes of the bookstore element
//*
Selects all elements in the document
//title[@*]
Selects all title elements which have any attribute
Selecting Several Paths
By using the operator in an XPath expression you can select several paths.
In the table below we have listed some path expressions and the result of the expressions:
Path Expression
Result
//book/title //book/price
Selects all the title AND price elements of all book elements
//title //price
Selects all the title AND price elements in the document
/bookstore/book/title //price
Selects all the title elements of the book element of the bookstore element AND all the price elements in the document