With STL it is possible to show or to hide an XML element based on a condition. For this purpose we use the stl:if attribute:
<a href="edit_task" stl:if="can_edit">${title}</a>
<span stl:if="not can_edit">${title}</span>
With the example above we will either have a link to a form to edit the task, or we will just have the title of the task. Depends on the value of the variable can_edit.
This is the syntax of the stl:if attribute:
stl:if="[not] expression"
The value of the stl:if attribute is a boolean expression, the same boolean expressions we have seen in Section .
Something important to note from the previous template snippet is that the language STL uses XML namespaces, this means that the STL namespace must be declared:
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns:stl="http://xml.itools.org/namespaces/stl"
...