I finally got this working. The trick was to use a global variable in the faraday on_complete - I tried to find a better solution but this was the best I could do. Once again, I got the header code from here. Here's the full guide to how to get pagination working with Her:
First, on my server side, I have the Kaminari gem, and I pass page
and per
as params to the server from the client. (This is also using ransack for searching)
def search
@search = Order.order('id desc').search(params[:q])
@orders = @search.result(distinct: true).page(params[:page]).per(params[:per])
respond_with @orders.as_json(include: :items)
end
My client makes the request like so:
@orders = Order.search(q: { client_id_eq: @current_user.id }, page: params[:page], per: 3)`
Back on the server, I have this in my ApiController (app controller for api):
protected
def self.set_pagination_headers(name, options = {})
after_filter(options) do |controller|
results = instance_variable_get("@#{name}")
headers["X-Pagination"] = {
total_count: results.total_count,
offset_value: results.offset_value
}.to_json
end
end
In the server orders_controller.rb, I set the pagination headers for the search method:
class OrdersController < ApiController
set_pagination_headers :orders, only: [:search]
...
end
Now to receive the headers we need a Faraday middleware in Her on the client.
# config/initializers/her.rb
Her::API.setup url: Constants.api.url do |c|
c.use TokenAuthentication
c.use HeaderParser # <= This is my middleware for headers
c.use Faraday::Request::UrlEncoded
c.use Her::Middleware::DefaultParseJSON
c.use Faraday::Adapter::NetHttp
c.use Faraday::Response::RaiseError
end
# lib/header_parser.rb
# don't forget to load this file in application.rb with something like:
# config.autoload_paths += Dir[File.join(Rails.root, "lib", "*.rb")].each { |l| require l }
class HeaderParser < Faraday::Response::Middleware
def on_complete(env)
unless env[:response_headers]['x-pagination'].nil?
# Set the global var for pagination
$pagination = JSON.parse(env[:response_headers]['x-pagination'], symbolize_names: true)
end
end
end
Now back in your client controller, you have a global variable of hash called $pagination; mine looks like this:
$pagintation = { total_count: 0, offset_value: 0 }`
Finally, I added Kaminari gem to my client app to paginate the array and get those easy pagination links:
@orders = Kaminari.paginate_array(@orders, total_count: $pagination[:total_count]).page(params[:page]).per(params[:per_page])`
I hope this can help someone else, and if anyone knows a better way to do this, let me know!