HP e-CommerceXML Accelerator sa7150 User Manual

Page 31

C H A P T E R 3

XML Operations

An XML expression’s first element must be preceded by a step
operator.

The node to the left of the last step operator in an XML expression is
the “context node,” i.e., the node that establishes the level within the
XML data tree’s hierarchy at which the SA7150 searches for a match
when comparing XML data to XML expressions. The “root node” is
the top level of the XML data tree, and by implication is to the left of
an XML expression’s left-most step operator. Some examples of the
effects of step operators are:

•

//address

Tells the SA7150 to search for the

element anywhere in the XML data tree.

•

//employee//state

Tells the SA7150 to search anywhere

under the

element node for the

element.

•

//employee/address

Tells the SA7150 to search one level

below the

node for the

element.

You can specify an element as “*”, which selects any element relative
to the context node. You can also specify an optional filter at the end
of a path to further refine parsing of the XML data stream.

Step
Operator

Name

Description

Child
operator

Selects all immediate children of the context node

Descendant
operator

Selects elements at any level under the context node

XML Step Operators