Viewing Processing Information

Stylus Studio provides several tools for viewing processing information. The tools become active when processing reaches a breakpoint. This section discusses the following topics:

Watching Particular Variables

Use the Watch window to monitor particular variables. To display the Watch window, click Watch in the Stylus Studio tool bar. This button is active when Stylus Studio suspends processing because it reached a breakpoint. Stylus Studio displays the Watch window only when processing is suspended.

Enter the names of the variables you want to watch. You can enter as many as you like. When Stylus Studio suspends processing, it displays the current values for any variables listed in the Watch window. You can expand and collapse complex structures as needed.

During XQuery debugging, you can enter XPath expressions in the Watch window fields. Stylus Studio uses the current context to evaluate these expressions, and displays the results with the same kind of interface Stylus Studio uses for nodeList and node variables.

Evaluating XPath Expressions in the Current Processor Context

When you suspend processing, you can evaluate an XPath expression in the context of the suspended process. You do this in the Watch window. Click in the Stylus Studio tool bar to display the Watch window. Click in an empty name field and enter an XPath expression. As soon as you press Enter, Stylus Studio displays the results of the evaluation in the Value field of the Watch window.

Obtaining Information About Local Variables

Display the Variables window to obtain information about local variables. To display the Variables window, click Variables in the Stylus Studio tool bar. This button is active when Stylus Studio suspends processing because it reached a breakpoint. Stylus Studio displays the Variables window only when processing is suspended.

Information displayed in the Variables window includes:

l Information about how the return value (displayed in the Variables window as __Return_Value_3, for example) is being built
l Local and global XQuery variable values

Also, you can navigate the structure associated with a variable, a parameter, or the current context if it is a node list or a node.

Displaying a List of Process Suspension Points

Display the Call Stack window to view a list of the locations at which processing was suspended. For XQuery files, Stylus Studio displays the XQuery file name and line number.

To display the Call Stack window, click Call Stack in the Stylus Studio tool bar. This button is active when Stylus Studio suspends processing because it reached a breakpoint. Stylus Studio displays the Call Stack window only when processing is suspended.

When processing is complete, the call stack is empty.

When execution is suspended you can use the Call Stack window to jump directly to the XQuery source. Double-click on a stack line to go to that location. A green triangle appears to indicate this location in the source file.

Displaying XQuery Expressions for Particular Output

After you create an XQuery, or during XQuery debugging, Stylus Studio can display the XQuery expression that generated a particular part of a result document. This can be particularly helpful when the result is not quite what you want.

In the Preview window, click on the output for which you want to display the XQuery expression. You can do this while either the text view or the browser view is active. Stylus Studio flags the line in the XQuery source that contains the expression that generated the output you selected.

 
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