Create input, condition, and output expressions in the XPath expression editor. XPath is a query language that performs computations and arithmetic calculations on hierarchical elements.
You can use XPath expressions to define the context for a statement or to define conditions to transform and filter the data. The function library in the expression editor is standard for the W3C XML Path Language.
When you click the Expression Editor button in the input, condition, or output property of a statement, the expression editor appears. The following image shows the expression editor:
1Add functions, source elements, or target elements to the expression.
2Edit the expression.
3Validate the expression.
4Undo and redo edits to the expression.
You can add functions, source elements, and target elements to the expression by clicking Add next to the function or element that you want to use. You can also type in the expression manually. To validate the expression, click Validate.