Jsonapi-resources: custom record_count like methods

[Fedcomp]

How do i make custom methods like record_count? not possible without monkey patching? record_count is hardcoded in FindOperation, any way i can replace with my custom operation?
Say, i want to group results by category and output in total meta information.

[gottfrois]

I'm also interested for a solution here. I'm using mongoid where the count method do not take any parameter unlike the active-record version.

[lgebhardt]

Yesterday I merged a branch that reworks the operation processing aspect of the gem. The old global OperationsProcessor is out and individual resource processors are in (a default one can be defined as well). See https://github.com/cerebris/jsonapi-resources#operation-processors

I think this should give you the flexibility you need. But please see the note at the end of the section. If you override the find method it may not pickup future changes if we alter how find works.

As of now this is only on the master branch, though I hope to get a beta release out soon.

[Fedcomp]

i'm afraid i phrased it wrong. I was asking for a way to _add_ methods like record_count. So i could have my own methods like aggregate_by(:field) in FindOperation and then use them in my own operation_processor to say, add faceted search metadata in response. Currently lib is highly coupled, and not allowing to substitute own class implementations.

[lgebhardt]

@Fedcomp I think I understand, but maybe not. The processor replaces the code that was buried on the FindOperation. So it gives you a place to implement your own code to override the default find implementation. You could add your custom methods on a resource specific processor or on a customized default processor. Look at the Api::V4::BookProcessor example in the link above.

[gottfrois]

@lgebhardt thanks for the clarification. I'm still afraid of this kind of code in master https://github.com/cerebris/jsonapi-resources/blob/master/lib/jsonapi/processor.rb#L163

I think you should have an interface defined on the resource that basically proxy the count call to the records. This way, one, can simply override the method definition in the resource if he needs to:

class FooResource < JSONAPI::Resource
  def self.record_count(*args)
    records.count(*args)
  end
end

Where, in my case would be as simple as records.count

[lgebhardt]

@gottfrois Does #720 work for you? It's a little different than you propose. I might be making a wrong assumption that it's the :all that AR now requires that's messing you up. With the proposed PR you could override this on a resource level, but there isn't the option to pass in custom arguments as you proposed.

[gottfrois]

This will work fine for now. The PRs does not replace all records.count(:all) occurrences though right?

[lgebhardt]

@gottfrois Thanks, I had missed a call to count in the processor. Now there's one place to override the records.count(:all) for a resource (or all resources).