Debugging and Testing Expressions

Enabling tracing can result in a large amount of trace data.

Use the following functions to enable expression trace or print text to help diagnose problems in an expression.

Globally enabling trace may result in a large amount of trace data being printed. If it is usually better to enable trace at the block level by setting the trace attribute of the block element to true.

trace Function

Enables or disables expression tracing. If the argument evaluates to true, tracing is enabled.

If tracing is enabled, it will go to standard output.

Example 1

<trace><i>1</i></trace>

Example 2

<trace><i>0</i></trace>

print Function

Prints the value of each subexpression to standard output.

Example

<print>
   <s>Ashley World!</s>
</print>