Exclude attribute in Collection

Question

I have a multi-select product attribute and i am wanting to exclude several values from a collection.

i.e

attribute = filter_theme
possible values = A, B, C, D, E, F, G, H

If i use nin like so:

$collection->addAttributeToFilter('filter_theme', array('nin' => $exclude));

It will only work if the products only have a single selection on filter_theme i.e value A

If they have more than one it won't work i.e values A & B. (I know this is also the case when using in to find rather than exclude)

Again i know that i can use finset to find any products with $exclude, whether it has 1 or all options selected:

$collection->addAttributeToFilter('filter_theme', array('finset' => $exclude));

This will work on both value A only and value A & B & Cbeing selected.

Is there a way of doing the opposite of finset to exclude rather than include so that it works no matter how many values are selected for my attribute?

Answer 1

What about using finset and manipulating your array instead?

You could do the following:

$possibleValues = array('A','B','C'...);
$excludeValues = array('B', 'C'...);

$includeValues = array_diff($possibleValues, $excludeValues);

And then you can just use your finset on includeValues