Redesign pagination

[d4be4st]

Currently jsonapi-query-builder only support pagy https://github.com/infinum/jsonapi-query_builder/blob/master/lib/jsonapi/query_builder/mixins/paginate.rb
It also takes care of building meta and liks via pagination_options.

I believe we can do better!

Idea is to create a warpper/builder class that can be used in controllers and would take the responsibiliy of building links and meta out from SerializerOptions

Lets take a look first at how the API would look:

class UserController
  builder = JsonApi::Builder.new(scope: User.all, params: params, query: Api::Users::Query)
  respond_with builder, serializer: Api::Users::Serializer, meta: {additional: 'meta'}
end

class JsonApi::Builder
  # initialziers
  def records
     query.new(scope, params, paginator: paginator).records
  end
  
  def options
     { meta: paginator.build_meta, links: paginator.build_links }
  end

  def paginator
     if cursor_pagination?
        JsonApi::Paginators::Cursor
    else
       JsonApi::Paginators::Page
    end
  end
end

# in the intitializer, render method:

ActiveSupport::Notifications.instrument('render.json_api', builder: builder, opts: opts) do
  # old code

  serializer.new(builder.records, builder.options.merge(opts)).serializable_hash.to_json
end

This also means we need to do work on the query-builder where it can accept a paginator class and work with it.

What do you think?

[nikajukic]

@d4be4st how/where would you include choosing a pagination gem?

[d4be4st]

@d4be4st how/where would you include choosing a pagination gem?

This is a really good question.
The setup/query_builder gem could have all the pagination startegies already coded up.
So lets say we have JsonApi::PaginationStrategy::OrderQuery, JsonApi::PaginationStrartegy::PagyCursor, JsonApi::PaginationStrartegy::Pagy, JsonApi::PaginationStrartegy::Kaminari already coded up so we can just use them.
What the setup gem would then gives us is a hook where we can code the ifology/switch:

paginator_builder: -> proc (params) {
  if params.dig(:page, :type) == 'cursor'
   JsonApi::PaginationStrategy::OrderQuery
  else
    JsonApi::PaginationStrartegy::Kaminari
  end
}

this way each application can build their own proc and introduce their own strategies that might not be avaliable already

---

Another way we can do this is build everything in setup/query_builder gem so we all use the same paginator_builder and strategies. The cursor/page switch would always go through params and the which specific strategy is picked depends on the gems you have installed.