Check the opt:include "view" attribute behaviour, if the object is not a valid
view.

>>>>templates/test.tpl
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!-- Include a view -->
<opt:root>
Foo
<opt:include view="$view">
Sorry
</opt:include>
</opt:root>

>>>>expected.txt
OUTPUT

>>>>result.txt
FooSorry
>>>>data.php
$view->view = 'Foo';