如何显示特定帖子？动作控制器 Ruby on Rails

Question

我正在尝试制作 Podcast 页面。在索引页面上，我想在顶部显示最新的播客，在中间显示接下来的三个播客，在页面底部显示其余所有播客

例如，我有 25 集，想显示如下

25 在顶部

中间是22、23、24

21,20,19,18 ~ 1 在底部

我的控制器

class PodcastsController < ApplicationController
  before_action :find_podcast, only: [:show, :edit, :update, :destroy]

  # GET /podcasts
  # GET /podcasts.json

  def index
    @podcasts = Podcast.order("created_at DESC").limit(1)

  end



  # GET /podcasts/1
  # GET /podcasts/1.json
  def show
    @podcasts = Podcast.all
  end

  # GET /podcasts/new
  def new
    @podcast = Podcast.new
  end

  # GET /podcasts/1/edit
  def edit
  end

  # POST /podcasts
  # POST /podcasts.json
  def create
    @podcast = Podcast.new(podcast_params)

    respond_to do |format|
      if @podcast.save
        format.html { redirect_to @podcast, notice: 'Podcast was successfully created.' }
        format.json { render :show, status: :created, location: @podcast }
      else
        format.html { render :new }
        format.json { render json: @podcast.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /podcasts/1
  # PATCH/PUT /podcasts/1.json
  def update
    respond_to do |format|
      if @podcast.update(podcast_params)
        format.html { redirect_to @podcast, notice: 'Podcast was successfully updated.' }
        format.json { render :show, status: :ok, location: @podcast }
      else
        format.html { render :edit }
        format.json { render json: @podcast.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /podcasts/1
  # DELETE /podcasts/1.json
  def destroy
    @podcast.destroy
    respond_to do |format|
      format.html { redirect_to podcasts_url, notice: "#{@pocast.title} was successfully destroyed." }
      format.json { head :no_content }
    end
  end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def podcast_params
      params.require(:podcast).permit(:episode_url, :episode_title, :episode_description, :episode_audio_url, :episode_number)
    end
end

index.html.haml

%section.no-spacing
  .row   
    .columns.large-12
      - @podcasts.each do |podcast|
         %h3
           = podcast.episode_number
           = podcast.episode_audio_url
           = podcast.episode_description

到目前为止，我可以显示最新的一页，但坚持按降序显示三页（第 2、第 3、第 4）和其余页面（第 5 ~ 全部）。

提前感谢您的帮助。

Answer 1

我会尝试这样的。
首先，让一个干净的控制器和一个查询对象与播客列表逻辑一起工作会很棒。

class PodcastsController < ApplicationController

  def index
    podcast_query = PodcastQuery.new
    # this is one podcast object
    @most_recent_podcast = podcast_query.most_recent
    # these are arrays of podcasts
    @next_three_most_recent_podcasts = podcast_query.next_three_most_recent
    @remaining_podcasts = podcast_query.remaining
  end
end

# app/models/podcast_query.rb
class PodcastQuery
  def initialize
    @podcasts = Podcast.order("created_at DESC")
  end

  def most_recent
    @podcasts[0] || (raise StandardError.new "you need at least one Podcast")
  end

  def next_three_most_recent
    @podcasts[1..3] || []
  end

  def remaining
    @podcasts[4..-1] || []
  end
end

Answer 2

首先，将限制更改为 25。

def index
  @podcasts = Podcast
    .order("created_at DESC")
    .limit(25)
end

然后使用Array#shift 将您需要的元素从数组中取出。

latest = @podcasts.shift
next_three = @podcasts.shift(3)
the_rest = @podcasts