为rails Restful API返回不同类型的资源答案

【问题标题】：Returning resources with different types for rails Restful API为rails Restful API返回不同类型的资源
【发布时间】：2021-02-11 22:14:40
【问题描述】：

我正在根据客户端发送的 json 请求使用 ruby 实现搜索端点，该请求的格式应为 GET /workspace/:id/searches? filter[query]=旧&filter[type]=ct:Tag,User,WokringArea&items=5 控制器是这样的

class SearchesController < ApiV3Controller
    load_and_authorize_resource :workspace, class: "Company"
    load_and_authorize_resource :user, through: :workspace
    load_and_authorize_resource :working_area, through: :workspace

    def index
      keyword = filtered_params[:query].delete("\000")
      keyword = '%' + keyword + '%'
      if filtered_params[:type].include?('User')
        @users = @workspace.users.where("LOWER(username) LIKE LOWER(?)", keyword)
      end
      if filtered_params[:type].include?('WorkingArea')
        @working_areas = @workspace.working_areas.where("LOWER(name) LIKE LOWER(?)", keyword)
      end
      @resources = @working_areas

      respond_json(@resources)
    end

    private

    def filtered_params
      params.require(:filter).permit(:query, :type)
    end

    def ability_klasses
      [WorkspaceAbility, UserWorkspaceAbility, WorkingAreaAbility]
    end
  end

respond_json以json格式返回资源，看起来是这样的

def respond_json(records, status = :ok)
if records.try(:errors).present?
  render json: {
    errors: records.errors.map do |pointer, error|
      {
        status: :unprocessable_entity,
        source: { pointer: pointer },
        title: error
      }
    end
  }, status: :unprocessable_entity
  return
elsif records.respond_to?(:to_ary)
  @pagy, records = pagy(records)
end

options = {
  include: params[:include],
  permissions: permissions,
  current_ability: current_ability,
  meta: meta_infos
}

render json: ApplicationRecord.serialize_fast_apijson(records, options), status: status

结束

现在的问题是响应应该是这样的：

{
data: [
    {
        id: 32112,
        type: 'WorkingArea'
        attributes: {}
    },
    {
        id: 33321,
        type: 'User',
        attributes: {}
    },
    {
        id: 33221,
        type: 'Tag'
        attributes: {}
    }

如何使我的代码支持响应具有不同类型的资源？

【问题讨论】：

标签： ruby-on-rails json ruby-on-rails-5 rails-api

【解决方案1】：

您可以基于 API 的结果定义模型，而不是在您的数据库中。然后包含一些 ActiveModel 模块以获得更多功能。

# app/models/workspace_result.rb
class WorkspaceResult
  include ActiveModel::Model
  include ActiveModel::Validations
  include ActiveModel::Serialization

  attr_accessor(
    :id,
    :type,
    :attributes
  )

  def initialize(attributes={})
    filtered_attributes = attributes.select { |k,v| self.class.attribute_method?(k.to_sym) }
    super(filtered_attributes)
  end

  def self.from_json(json)
    attrs = JSON.parse(json).deep_transform_keys { |k| k.to_s.underscore }
    self.new(attrs)
  end
end

然后在您的 API 结果中，您可以执行以下操作：

results = []
response.body["data"].each do |result|
  results << WorkspaceArea.from_json(result)
end

还可以在这个模型上定义实例方法等

【讨论】：