Question

How can one define a default value for a facelet template parameter?
Consider the following element using a template parameter:

<h:outputText value="#{templParam}"></h:outputText>

The above line will print the the template parameter templParam which is passed by a ui:param tag in a ui:composition using the template:

<ui:param name="templParam" value="Hello world"></ui:param>

But if ui:param tag is missing nothing will be printed. Although, how can one print e.g “Default value” in this case?

Answer 1

A default value can be defined by using a ternary operator checking for null value.

<h:outputText value="#{templParam != null ? templParam : 'Default value'}"></h:outputText>

This will print “Default value” if the parameter was not passed by a ui:param tag.