Expression Builder Dialog

2.32 Expression Builder Dialog

Use to visually design XPath expressions in the selected service component (BPEL process or Oracle Mediator).

Element	Description
Expression	Displays the XPath expression that you are building. Double-clicking items in the Functions palette and the BPEL Variables section (for a BPEL process), Business Event section (for Oracle Mediator or certain activities of a BPEL process such as an invoke, reply, receive, or onMessage branch of a pick activity), or Variables section (for Oracle Mediator) builds the XPath expression in the Expression field. You can also create or edit expressions directly in the Expression field by invoking the XPath Building Assistant by pressing Ctrl+Space. How? By default, XPath expressions are validated as you create them with the XPath Building Assistant. You can disable validation to improve performance during XPath expression creation. Select Tools > Preferences > SOA and disable the Validate Expression checkbox. Once expression validation is disabled, no underlines display to indicate possible errors or warnings for the XPath expression. Note: If your expression is complete, but you are still being prompted to enter information, press Esc. This closes the list.
BPEL Variables, Business Event, or Variables	Create XPath expressions by expanding and selecting required items. The items available for selection are based on the selected service component. For a BPEL process, the item is a variable. For Oracle Mediator or certain activities of a BPEL process such as an invoke, reply, receive, or onMessage branch of a pick activity, the item is a business event, to which it is subscribed, or a variable. Build an XPath expression in this section by single-clicking elements. For example, expanding and single-clicking Variables > output > Variable > payload > ns1:OrderItems > ns1:Item > ns1:ProductName for a BPEL process service component displays a preview version of the XPath expression in the Content Preview field at the bottom left. When the XPath expression is complete, double-click the last element or click Insert Into Expression to display it in the Expression field at the top. Note: The name of this section is based on the service component in which you are creating the XPath expression: For a BPEL process, this section is named BPEL Variables or, if you accessed this dialog by selecting Event as the Interaction Type in activities such as an invoke, reply, receive, or onMessage branch of a pick activity, this section is named Business Events. For Oracle Mediator, this section is named either Variables (if defining an interface) or Business Event (if subscribing to an event).
Functions	Select a category of functions from the list in order to build XPath expressions. Each category contains a number of specific functions. The functions available for selection are based on the selected service component. Single-clicking a function displays a detailed description (including syntax usage) in the Description field at the bottom. A preview version of the function also displays in the Content Preview field at the bottom left. The syntax usage describes the expected arguments for the selected function. These arguments can be variables, parts, elements, literals, or other functions. Insert a function into the Expression field by double-clicking it or clicking Insert Into Expression. For example, double-clicking the concat string function displays it in the Expression field. Enter an argument for the selected function by placing the cursor inside the function in the Expression field and double-clicking the BPEL variable expression or function to insert. For example, place the cursor inside the parentheses of concat() and select the BPEL variable syntax. The expression is inserted at the cursor position. Note: You can specify a literal or number by manually entering it in the Expression field. A literal must be specified in single quotes.
Insert into Expression	Click to insert the created expression into the Expression field.
Undo Last Edit icon	Click to undo your last edit in the Expression field.
Redo Last Edit icon	Click to redo your last edit in the Expression field.
Clear Expression icon	Click to clear the Expression field.
Content Preview	Displays details about your selection.