[not_so_young_greg]

Originally Posted by vladimir.gritsenko

Thanks for noticing it. Actually, this is a tricky issue. Let me try to explain.

Imagine there are two classes with two options each, combined in four variants. For example,

Color: Red, Green
Size: S, L

the resulting variants are:

Red S
Red L
Green S
Green L


Now, let's say "Red S" variant is out of stock. How in this case should the filtering behave? In fact, there is no problem if the filters selection is as follows:

Color: Red
Size: S

Yes. In this case if "in stock only" is checked it should show nothing. If is unchecked,should show Red S

Originally Posted by vladimir.gritsenko

In this case we can disable "In stock only" filter but what if it's chosen like:

Color: [not selected]
Size: S

or

Color: Red, Green
Size: S

Should it disable "In stock only" filter in these particular cases? It's a hard question, isn't it?

In my opinion: In your first example color: [not selected] it should show Red S and Green S, if "only in stock" is unchecked. Otherwise should show only Green S.
If a customer wants Red and Green in size S (quite common I think), the filter should behave alike: if "in stock only" is checked, shows Green S (Red S is out of stock), otherwise shows both items.

Originally Posted by vladimir.gritsenko

This is a very basic variants example. Imagine, there are 10 classes with 10 options each. A customer will have to choose one and only one attribute from each variants-related filter to have "In stock only" react basing on variants stock levels.

I perfectly know from my experience that variants are confusing and power-consuming.
But what is actually funny is that every filter I have had a look at, had "filter by size" option, obviously designed for apparel stores. And they were all based on option classes, disregarding availability.
But we all know that when a clothing store owner buys a jacket, he buys sizes S,M,L,XL,XXL etc., at least in most cases. And soon he ends up with only L in stock, the thing cannot be reordered because it is last fall collection and so on.

In a case like this filtering by size is useless since most items have all the sizes. If a customer searches for size L, he definitely should have an option "show only what is in stock".
Otherwise this filter is good only for people who search for a quadruple L or XXS - sizes that are not so common.
And adding "in stock only" filter is only confusing because apparently it does not filer by availability.

By the way: what is this filter for? To show in-stock items when "show out of stock items" is checked in apperance settings?

But thanks for your answer. I know you guys will come up with a good solution soon.