ruby-on-rails - ActiveRecord::Serializer 中的条件侧载数据(基于 Controller 操作)

Question

我在 Rails 和构建应用程序方面没有太多经验。我尝试使用 ActiveModel::Serializers 构建 API。

为特定事件操作有条件地加载数据的最佳方法是什么？

我是否必须通过在每次调用时发送查询参数来做到这一点，或者我可以设置 includes:true only for specific action or any other suggestion？

class EventsController < ApplicationController
  before_filter :authenticate_user!, :except => [:index, :show]
  before_filter :locate_collection, :only => :index
  skip_before_filter :verify_authenticity_token, :only => [:create, :index, :show]
  before_action :set_event, only: [:show, :edit, :update, :destroy]

  # GET /events
  def index
    if params.has_key?("mode") and params[:mode] == "owned"
      own_event
    else
#       @events = Event.all
      render json: @events
     end
  end

  # GET /events/1
  def show
    render json: @event
  end

  # GET /events/new
  def new
    @event = Event.new
  end

  # GET /events/1/edit
  def edit
  end

  # POST /events
  # POST /events.json
  def create
    @event = Event.new(event_params)
    @event.creator_user_id = current_user.id
    if @event.save
      render json: @event
    else
      render json: @event.errors, status: :unprocessable_entity
    end
  end

  # PATCH/PUT /events/1
  # PATCH/PUT /events/1.json
  def update
    if @event.update(event_params)
      render json: @event
    else
      render json: @event.errors, status: :unprocessable_entity
    end
  end

  # DELETE /events/1
  # DELETE /events/1.json
  def destroy
    aa = @event.destroy
    render json: aa
  end 

     def own_event
       @events = Event.where(creator_user_id: current_user.id)
      if @events.count > 0
        render json: @events
      else
        render json:   []
      end
#     else
#         render json: {error: 1, message: "Events not found."}, status: 404
#     end
  end

  def locate_collection
    if (params.has_key?("filter"))
      @events = EventPolicy::Scope.new(current_user, Event).resolve(filtering_params)
#       @event_orders = EventOrder.filter(filtering_params)
    else
      @events = policy_scope(Event)
    end 
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_event
      @event = Event.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.


  def filtering_params
    params.slice(:event_type_id)
  end

end

    **My Event serializer**
It includes data for multiple association listed below. i don't want to show all the data with event call.
    class EventSerializer < ActiveModel::Serializer
  attributes :id, :event_name, :event_start_date, :event_end_date, :creator_user_id, :event_proposal_id, :daily_start_time, :daily_start_time, :payment_category, :total_capacity, :contact_email, :description, :graced_by, :contact_details, :video_url, :demand_draft_instructions, :status, :cannonical_event_id, :website, :event_type_id, :additional_details, :event_start_time, :event_end_time, :committee_id

  embed :ids
  has_one :address, include: true
  has_many :tickets, include: true
  has_many :event_cost_estimations, include: true
  has_many :event_seating_category_associations, include: true
  has_many :event_awarenesses, include: true
  has_one  :pandal_detail, include: true
  has_one  :bhandara_detail, include: true
  has_many :event_tax_type_associations, include: true
  has_many :event_team_details, include: true
  has_one :event_type, include: true
#   has_many :event_registration_center_associations, include: true
  has_many :registration_centers, include: true
#   has_many :event_registrations, include: true
  has_many :event_orders, include: true
  has_one :venue_type
end

 In event serializer i have includes :true for sideloaded data and I want to show sideloaded data(includes: true) of registration_centers and tickets only for index action. 

我能为此做什么？

Answer 1

考虑到您使用的是 AMS 版本 0.8.x，

您可以像这样创建一个 base_serializer.rb 并扩展它。

class BaseSerializer < ActiveModel::Serializer
  def include_associations!
    if @options[:embed]
      embed = @options[:embed].split(',').map!(&:to_sym)
      embed.each do |assoc|
        include! assoc if _associations.keys.include?(assoc)
      end
    end
  end
end

class EventSerializer < BaseSerializer

而EventsController中的index方法可以写成

# GET /events?embed=registration_centers,tickets
  def index
    if params.has_key?("mode") and params[:mode] == "owned"
      own_event
    else
#       @events = Event.all
      render json: @events, embed: params[:embed]
     end
  end

我刚刚向您展示了可以在 url 参数中添加所需的关联。您可以想出一些聪明的方法来发送参数，这样您就不需要将它们添加到 url 请求中。