The test checks ignoring attributes.

>>>>templates/test.tpl
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<opt:root>
<foo opt:attributes-build="$input" opt:attributes-ignore="$ignore">
bar
</foo>
<foo opt:attributes-build="$input" opt:attributes-ignore="'abc,foo'">
bar
</foo>
</opt:root>

>>>>data.php
$view->input = array(
	'abc' => 'def',
	'foo' => 'bar'
);
$view->ignore = array('abc');

>>>>expected.txt
OUTPUT

>>>>result.txt
<foo foo="bar">
bar
</foo>
<foo>
bar
</foo>