ruby-on-rails – ActiveModel序列化程序：如何序列化资源集合？

namespace :api,defaults: {format: 'json'} do
    resources :bookmarks
    get ':username',to: 'users#index'
    get ':username/bookmarks/:id',to: 'users#show'
  end

我有一个Api :: UsersController控制器和一个支持的BookmarkSerializer,可以在单个书签资源上正常工作,如http：// localhost：3000 / api / emma_carter / bookmarks / 87

但是当我尝试点击http：// localhost：3000 / api / emma_carter时,它应该为用户拥有的所有书签提供服务,我会遇到各种不同的错误.这是我的Api :: UsersController

module Api
    class UsersController < ApplicationController
        respond_to :json

        def index
            user = User.find_by(username: params[:username])
            bookmarks = user.bookmarks
            render json: bookmarks
        end

        def show
            user = User.find_by(username: params[:username])
            bookmark = user.bookmarks.find_by(params[:id])
            render json: bookmark
        end
    end
end

show方法有效但索引方法在Api :: UsersController#index中给出了ArgumentError

wrong number of arguments (1 for 0)

更新：完整堆栈跟踪：https://gist.github.com/amite/b79fc42bfd73de5a07bd

截图

这是序列化器：

class BookmarkSerializer < ActiveModel::Serializer
    attributes :id,:url,:title,:domain,:notes,:image,:created,:username
    belongs_to :user

    def created
        object.created_at
    end

    def username
        user.username
    end
end

看看堆栈溢出的其他解决方案,我也尝试过其他版本的索引方法：

def index
            user = User.find_by(username: params[:username])
            bookmarks = user.bookmarks
            bookmarks.map { |bookmark| ::BookmarkSerializer.new(bookmark)}.to_json #updated line
        end

这给了我错误：

Missing template api/users/index,application/index with {:locale=>[:en],:formats=>[:json],:variants=>[],:handlers=>[:erb,:builder,:raw,:ruby,:coffee,:jbuilder]}.

接下来,我的索引方法的最后一个版本如下所示：

def index
  user = User.find_by(username: params[:username])
  bookmarks = user.bookmarks
  ActiveModel::ArraySerializer.new(bookmarks,each_serializer: ::BookmarkSerializer).to_json
end

这给了我未初始化的常量ActiveModel :: ArraySerializer错误

我究竟做错了什么？我正在使用rails 4.1.5和active_model_serializers的github版本
宝石.

gem 'active_model_serializers',github: 'rails-api/active_model_serializers'

更新：因为我试图输出书签集合,我也尝试使用单独的序列化程序
BookmarksSerializer但我得到了同样的错误：Api :: UsersController #index中的ArgumentError
错误的参数个数(1表示0)

UPDATE2：这是索引方法的一个版本,它在某种意义上有效,它以json格式呈现资源集合：

def index
        user = User.find_by(username: params[:username])
        bookmarks = user.bookmarks

        respond_with bookmarks.to_json
    end

但是这仍然没有使用BookmarksSerializer

class BookmarksSerializer < ActiveModel::Serializer
    attributes :id,:title
end

它只输出默认哈希

完整的Gemfile

来源’https://rubygems.org‘

# Bundle edge Rails instead: gem 'rails',github: 'rails/rails'
gem 'rails','4.1.5'
# Use mysql as the database for Active Record
gem 'mysql2'
# Use SCSS for stylesheets
gem 'sass-rails','~> 4.0.3'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier','>= 1.3.0'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails','~> 4.0.0'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer',platforms: :ruby

gem 'bourbon'
gem 'neat'
gem 'bitters'
gem 'refills'

gem 'wisper'
gem 'rails-ioc'
gem 'reform'
gem 'cells'
gem "pundit"

gem 'active_model_serializers',github: 'rails-api/active_model_serializers'

gem "font-awesome-rails"

gem 'simple_form'

# Use jquery as the JavaScript library
gem 'jquery-rails'

# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder','~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc','~> 0.4.0',group: :doc

group :development,:test do
  # Call 'debugger' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'
  gem 'ffaker'
  gem 'pry-rails'

  gem 'capybara'
  gem 'factory_girl_rails'
  gem 'database_cleaner'
  gem 'capybara-webkit'
  gem 'rspec-cells'

  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'

  gem 'spring-commands-rspec'
  gem 'rspec-rails'
  gem 'guard-rspec'
  gem 'rb-fsevent' if `uname` =~ /Darwin/
end

# Use ActiveModel has_secure_password
gem 'bcrypt','~> 3.1.7'

# Use unicorn as the app server
# gem 'unicorn'

# Use Capistrano for deployment
# gem 'capistrano-rails',group: :development

# Use debugger
# gem 'debugger',group: [:development,:test]