Issues using custom scopes

[drj17]

Hey, thanks for the great work on this gem.

I'm trying to figure out how to get custom scopes to work, but it seems like this method in filtering.rb is stripping them out

jsonapi.rb/lib/jsonapi/filtering.rb

Lines 59 to 67 in a4a16e5

	wants_array = predicates.any? && predicates.map(&:wants_array).any?
	if to_filter.is_a?(String) && wants_array
	to_filter = to_filter.split(',')
	end
	if predicates.any? && (field_names - allowed_fields).empty?
	filtered[requested_field] = to_filter
	end

Is there a reason that filter options without predicates are removed? I have a scope called awaiting_review_by_user_id. I've added it to the ransackable scopes, and that works fine, but the method above removes it anyways. Is there an easy way to get this scope working? Locally removing the predicates.any? check fixed my issue, but maybe I'm missing something that's already built in.

[stas]

@drj17 would you be kind to provide some code, I'm not sure I understand what exactly fails. We are using this for filtering on scopes internally without any issues.

Just after a quick look, consider renaming the scope to something that includes also a predicate, instead of awaiting_review_by_user_id use awaiting_review_user_id_eq.

Generally speaking, you can extend the list of predicates and add anything to it (including a dummy predicate), but there should be something, otherwise things will get messy.

[drj17]

Hi @stas

I've put together a small sample project here https://github.com/drj17/jsonapi_sample

I can send a request to http://localhost:8081/todos?filter[awaiting_review_by_user_id]=some_user_id and when I put a debugger in jsonapi_filter_params I can see predicates is empty, causing filtered to return {}

I did try changing the name to awaiting_review_by_user_id_eq, and I was able to get it working only if the allowed fields did not include the predicate (allowed = [:awaiting_review_by_user_id]) but the scope and request did. Maybe this is intended?

[stas]

I did try changing the name to awaiting_review_by_user_id_eq, and I was able to get it working only if the allowed fields did not include the predicate (allowed = [:awaiting_review_by_user_id]) but the scope and request did. Maybe this is intended?

Yes, unfortunately this is how Ransack is also designed...
I reviewed the example you put together and I can confirm that having the scope follow the naming to include the predicate is the right way to do it...

Glad it worked for you.

Long-term, it would be nice to find a lighter alternative to ransack... but at the moment, I prefer to rely on what we have...

Thanks @drj17! Feel free to close the issue if that's ok with you.

[drj17]

Good to know. It might be worthwhile to have an example or caveat in the readme for cases like this, but it's nice have gotten it working without too much tweaking.

[stas]

Unfortunately working with filters requires quite a bit of knowledge of Ransack. If you have some time to document the use-case, I'll be happy to merge it!

Thanks again 🙃