How to count the number of checked Checkboxes with Rules?

Question

I have a Drupal Commerce site which uses user points (= coins) for paying.

I have a special case - the product, which the user should buy with his/her coins, needs some fields filled out by the user. So I used a content type for this case and when the user adds a new one, 10 coins will be reduced from the user's account - this works already fine.

Now I have also a taxonomy in this content type and the user can add terms to it, which are shown later in the form when the user fills it.

Problem :

I need to count how many checkboxes of the taxonomy terms are checked and multiply the costs with them. So if 3 of 5 are checked, then 10 coins * 3 = 30 coins will be the final price when the user adds a new content type.

Is this possible with Rules? I have no clue how to realize that (I´m front-end developer and no PHP coder).

Answer 1

Yes this is perfectly possible with Rules, and you don't need any PHP to get the job done. In your case, the crucial part of such rule is a Rules Action to perform a Loop. If you're not familiar with such loops, then I strongly recommend to have a look at the tutorial titled "Lists and loops".

In your case, you should use (at least) these Rules Actions:

• "Add a variable" (say with a machine name like nr_of_checked_terms), with initial value "0".
• Add a loop related to your taxonomy terms. After you do, you should iterate over each item in that list (= each taxonomy term). And for each iteration you should then perform a Rules Action to "Set a data value", whereas you actually increment the value of nr_of_checked_terms with "1".

After the loop finished, the value of nr_of_checked_terms will be the actual number of terms that were checked. Just add another Rules Action near the end to do your actual multiplication using nr_of_checked_terms as one of the available tokens.

Done

PS 1: Refer to my answer to "How to set multiple values to an unlimited Term Refence field with Rules" for some sample rules that are like a variation of your question here.

PS 2: I assume this is about D7 ...