Free Shipping Exclusions

The need is simple, the solution may not be. I'm looking to have free shipping on orders over $100, excluding items on sale.

I have read a number of threads on the forum on how to approach it, but one additional nuance for my store is presenting a problem, and that is all products are priced by attribute.

If you look at my site here you'll see three attributes to one product which is the various size bags of the specific candy. The "Limited Time Offer" is a sale item. Because it's on sale, I'd like to exclude it from the free shipping calculation.

I would like to have it one of two ways, if an attribute is in Sale Maker it is excluded from Free Shipping; or, by adding a new radio button to the Attribute Controller that says, "Exclude from Free Shipping." The latter may be easier, not sure though.

I've come to the conclusion I'm going to have to get my hands dirty and code this custom, which is no problem. However I'd love if the community to point me in the right direction, or if someone perhaps has already attempted something could share their code.

I'm using 1.3.8a.

Currently, how are you displaying the:
LIMITED TIME OFFER

on these attributes?

Is this just part of the Option Value Name or do you have a flag that creates those?

It the Product itself on Sale but all of the Attributes except the LIMITED TIME OFFER Attribute marked not to include the Sale/Special using the:
Apply Discounts Used
by Product Special/Sale: YES

only on the LIMITED TIME OFFER Attribute?

The "Limited time offer" text is just in the attribute name and modified with CSS.

Would there be a way to cheat and look for this text in the free shipping module?

I was contemplating that too, as your options_id/options_values_id vary from Product to Product ...

Are these "Limited time offer" Attributes the only attributes that are marked as:
Apply Discounts Used by Product Special/Sale: YES

No, everything is currently marked that way. However, I see no reason why this couldn't be used for that purpose.

Is this flag available somehow to the free shipping module?

No it isn't ... I am just trying to find something that might be able to be used as a flag for this ...

Right now it is pretty ambiguous and there is nothing to specifically identify these Products by their attributes ...

Usually, if it were a Product that would be easier to test for ...

Bummer... I was hoping for some way to hack this in without too much difficulty.

Do you know what is available to the free shipping module in terms of data coming from attributes?

For example, I could add a * to the end of an attribute that is on sale and, assuming the free shipping module can see that info, and check for any attribute name ending in that character.

What about using a special order number? I wouldn't mind the free shipping items appearing at the end if I could use the number as a flag.

Or I could just bite the bullet and add a custom field. Just trying to find the least path of resistance. :)

Thanks for your help thus far.

The Product is on Sale via SaleMaker or a Special?

And you have 2 of the 3 Attributes marked to NOT include the Specials/Sales ... correct?

Correct; and the text of that attribute includes a piece of text unique only to items that would be on sale.

So there are three unique things that identify what I want excluded from the free shipping calculation.

It could be done where the price for these Attributes is tracked in the shopping_cart class and could be called with a new function for the amount then that amount is subtracted from the references to:
MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING_OVER

It would take some time to piece this all together but it could be written ...