will_paginate JSON支持?
我想知道是否有人可以告诉我,如果will_paginate可以支持开箱即用的JSON,或者是否必须被黑客入侵?
我想将页面数据添加到JSON响应中,而will_paginate管理分页。
有点像:
@posts = Post.paginate :page => params[:page] respond_to do |format| format.json { render :json => { :current_page => @posts.current_page, :per_page => @posts.per_page, :total_entries => @posts.total_entries, :entries => @posts } } end
一旦找出想要的格式,就可以在WillPaginate :: Collection上定义to_json
方法。
将分页添加到API
我用will_pagination找到了一个简单的API Json Response Pagination解决方案。
首先在ApplicationController
中创建一个类方法,该方法将创建一个after_filter
,用于在响应头中设置分页元数据:
application_controller.rb
class ApplicationController < ActionController::Base protected def self.set_pagination_headers(name, options = {}) after_filter(options) do |controller| results = instance_variable_get("@#{name}") headers["X-Pagination"] = { total: results.total_entries, total_pages: results.total_pages, first_page: results.current_page == 1, last_page: results.next_page.blank?, previous_page: results.previous_page, next_page: results.next_page, out_of_bounds: results.out_of_bounds?, offset: results.offset }.to_json end end end
然后在控制器中我们想要添加分页标题,我们可以像这样调用它:
widgets_controller.rb
class Api::V1::WidgetsController < Api::V1::BaseController set_pagination_headers :widgets, only: [:index] def index @widgets = Widget.all.paginate(params).order("created_at desc") respond_with @widgets end end
响应标头看起来像这样
> Cache-Control:max-age=0, private, must-revalidate > Connection:keep-alive Content-Type:application/json; charset=utf-8 > Etag:"fe70f7bae4c6e5cdea7867aa7fc0c7b4" > X-Pagination:{"total":14,"total_pages":1,"first_page":true,"last_page":true,"previous_page":null,"next_page":null,"out_of_bounds":false,"offset":0} > Server:thin 1.3.1 codename Triple Espresso > Set-Cookie:_widgets_session=BAh7CEkiD3Nlc3Npb25faWQGOgZFRkkiJTAzYjVlNzkwZTIyNzU4YTYwMDU0M2MwOTQ2ZWI3YWU2BjsAVEkiDWxhc3RfdXJsBjsARkkiM2h0dHA6Ly9tYWluYW5kbWUtc3RhZ2luZy5oZXJva3VhcHAuY29tL3VzZXJzLzEGOwBGSSIQX2NzcmZfdG9rZW4GOwBGSSIxdjd0SEp6cVhKamh5YTh1cnBUdmpBb0w5aVA0bS9QTEdON3g1UlFUYnBkND0GOwBG--71b3a24c216a414d8db04f312b5300c818e6bba4; > path=/; HttpOnly Transfer-Encoding:Identity > X-Request-Id:61b383ade49cba8b24a715a453ed6e1f X-Runtime:0.191485 > X-Ua-Compatible:IE=Edge,chrome=1
源 - 将分页添加到API
这个帮助我:
将此方法添加到基本API控制器。
def pagination_dict(collection) { current_page: collection.current_page, next_page: collection.next_page, prev_page: collection.prev_page, # use collection.previous_page when using will_paginate total_pages: collection.total_pages, total_count: collection.total_count # use collection.total_entries when using will_paginate } end
然后,在渲染方法上使用它。
render json: posts, meta: pagination_dict(posts)
最简单的解决方案
def index @posts = Post.all.paginate(:page => params[:page], :per_page => 4) render :json => @posts.to_json(:methods => [:image_url]) end
你只需要添加gem 'will_paginate'
这个对我有用。
will_paginate只是以切片的方式取回记录。 所以它只是从你的数据库中获取一个数组。
当你渲染为json时,那些rails遍历对象数组并在它们上面调用as_json。
所以是的,你可以将渲染出来作为json。
我建议你观看这个Railscast: 使用AJAX进行分页