Skip to main content

Expression Tag

Learn how to write Yumdocs templates with expression tags.


Make sure you understand expressions before experimenting with expression tags.

About the Playground

The examples below are live to allow you to experiment. Most limitations come from the fact that the web editor for input.docx has few capabilities compared to Microsoft Word. But note that you can download input.docx, improve layouts in Word and run yumdocs input.docx data.json output.docx in a terminal window as explained in our CLI Tutorial.

An expression tag is simply an expression between delimiters {{ and }}, i.e. {{<expression>}}. The delimiters tell Yumdocs to evaluate the expression in-between the delimiters. Yumdocs then replaces the expression tag, including the delimiters, with the resulting value of evaluating the expression.

In the following example, {{person.salutation + " " + person.firstName|substr(0, 1) + ". "" + person.lastName|upper}} is replaced with Mr J. BLOGGS. Notice the use of the tranforms substr and upper.