XPath functions and operations in the BPEL mapper

The XPath expression Editor is used to handle some business process elements. The following expression is allowed for each element: a copy expression, a conditional expression, or a time function use.

User interface

The BPEL mapper has an intuitive user interface that is easy to use. When you select a BPEL diagram element that can contain an XPath expression, a bpel mapper window appears. The BPEL mapper is used for the following business process elements: Assign, if, ElseIf elements of If, ForEach, Repeatuntil, while, and wait. Each element has an expression that is allowed, including a copy expression, a conditional expression, and a time function usage. The conditional expression is defined for the ElseIf element of if, if, while, and repeatuntil elements. The copy expression is defined for the Assign element. The duration expression is defined for the wait element. A conditional expression with a parameter is defined for a ForEach element. Using the BPEL Mapper interface, you can calculate: Assign the XPath operations and functions above to local and global variables, XSD elements and attributes, and parts.

In the context menu of the BPEL Designer Design view, these business process elements have the show BPEL Mapper item. The context menu is available when you close the BPEL mapper window. You can also open the XPath Expression Editor window by selecting Window > BPEL Mapper from the main menu.

You can edit the XPath expression in the source text of the BPEL file, as shown in Figure 1. The BPEL mapper displays the correct modifications, as shown in Figure 2.

Figure 1:bpel File's Source view

Figure 2:assign1 Add operation

Functions and operators used in the BPEL mapper

The BPEL Mapper supports version 1.0 of the XML Path language (XPath 1.0). The XPath language is a key part of the XML platform. The XPath language developed by the consortium is a language used to resolve parts of the XML document structure. This language has functions for manipulating strings, numbers, and Boolean values. The main syntactic constructs of XPath are expressions. As a result of processing an expression, an object that belongs to one of the following four basic types is displayed:

Node Collection-unordered collection of nodes with no duplicates

Boolean-True or False

Number-number with floating-point numbers

string-UCS symbol sequence

XPath languages Support numeric expressions, equality and comparison operations, and Boolean expressions. The BPEL Mapper supports some XPath operations and functions.