JSONAPIHelpers

gem 'jsonapi_helpers'

require 'jsonapi_helpers'

include JSONAPIHelpers::Alias

JSONAPIHelpers.configure do |config|
  config.deserializer_klass = ActiveModelSerializers::Deserialization
  config.params_klass = ActionController::Parameters
  # optional (unaltered is the default)
  config.key_transform = :dash # camel, camel_lower, underscore, unaltered
end

# Error
errors = JSONAPIHelpers::Serializers::Errors.new
errors.add(status: 422, detail: 'too short', attribute: :first_name).to_h
errors.to_h
# => {
#   errors: [{
#     :status => 422,
#     :detail => 'too short',
#     :source => {
#       :pointer => "/data/attributes/first-name"
#     }
#   }]
# }

# In ApplicationController you can define
class ApplicationController < ActionController::Base
  # Define these constants in your controllers that you'd like to have
  # different/custom behavior
  DEFAULT_SORTING = { created_at: :desc }.freeze
  SORTABLE_FIELDS = [].freeze

  ALLOWED_INCLUDES = [].freeze

  TRANSFORMABLE_FILTERS = { created_at: :date_range }.freeze
  ALLOWED_FILTERS = %i(created_at).freeze

  def jsonapi_params
    @_deserialized_params ||= JSONAPIHelpers::Serializers::Deserializer.parse(params)
  end

  def include_params
    @_include_params ||= JSONAPIHelpers::Params::Includes.new(params[:include])
  end

  def fields_params
    @_fields_params ||= JSONAPIHelpers::Params::Fields.new(params[:fields])
  end

  def sort_params
    @_sort_params ||= begin
      sortable_fields = self.class::SORTABLE_FIELDS
      default_sorting = self.class::DEFAULT_SORTING
      JSONAPIHelpers::Params::Sort.build(params[:sort], sortable_fields, default_sorting)
    end
  end

  def filter_params
    @_filter_params ||= begin
      filterable_fields = self.class::ALLOWED_FILTERS
      transformable = self.class::TRANSFORMABLE_FILTERS
      JSONAPIHelpers::Params::Filter.build(params[:filter], filterable_fields, transformable)
    end
  end

  # ...
end