params详解

<%= 2.times do |f| %>

   <input type="hidden" name="subject[body_data][][origin_url]" value="<%= f[:origin_url] %>"></input>

   <input type="hidden" name="subject[body_data][][medium_url]" value="<%= f[:medium_url] %>"></input>

   <input type="hidden" name="subject[body_data][][width]" value="<%= f[:width] %>"></input>

   <input type="hidden" name="subject[body_data][][height]" value="<%= f[:height] %>"></input>
<%= end %>

或

   <input type="hidden" name="subject[body_data][][origin_url]" value="<%= f[:origin_url] %>"></input>

   <input type="hidden" name="subject[body_data][][medium_url]" value="<%= f[:medium_url] %>"></input>

   <input type="hidden" name="subject[body_data][][width]" value="<%= f[:width] %>"></input>

   <input type="hidden" name="subject[body_data][][height]" value="<%= f[:height] %>"></input>

   <input type="hidden" name="subject[body_data][][origin_url]" value="<%= f[:origin_url] %>"></input>

   <input type="hidden" name="subject[body_data][][medium_url]" value="<%= f[:medium_url] %>"></input>

   <input type="hidden" name="subject[body_data][][width]" value="<%= f[:width] %>"></input>

   <input type="hidden" name="subject[body_data][][height]" value="<%= f[:height] %>"></input>

以上二者相同，因为堆跌之后遇见最后一个参数（origiin_url或medium_url等等）相同时, 第二个参数自曾([])

params中存储的格式相当与 params = {"utf-8"=>"✓", "subject"=>{"title" => "fdsafdsafdsa", "body_data" => [{:origin_url =>HTML对应属性为name="subject[body_data][][origin_url]"的标签输入的值, :medium_url => fdas, :width => dsafds, :height => dasfsdfdas}, {:origin_url =>assadasdsa,
:medium_url => fdassss, :width => dssssafds, :height => dasfssssdfdas}]}}

!! 记住Subject的属性一定要存在params中key为subject的散列中

因为params完整性定义时要用

  private

    def subject_params

      params.require(:subject).permit(

        :user_id, :title, :description, :subject_type, :position, :status, :photo,

        body_data: [:content, :photo, :origin_url, :medium_url, :width, :height]

      )

 end

!!在后端中拿取<input type="hidden" name="subject[body_data][][origin_url]" value="<%= f[:origin_url] %>"></input>前端输入值用params[:subject][:body_data][0或者1或者遍历][:origin_url]

controller中params接受来自前端数据 并进行遍历(*****只有数组才可以对其遍历， 哈系不可以遍历  => 具体意思是[{type: "fdsa", content: "assaas"}, {type: "dsafsd", content: "aaaa"}]可以遍历    {{type: "dsaf", content: "dsafdsa"}, {type: "sdfa", content: "assaa"}}不可以遍历)

params[:subject][:body_data].each do |f|

p f[:origin_url]

p f[:medium_url]

p f[:width]

p f[:height]

end

实际情况

js:

$(document).ready(function(){

    $(".ui celled striped tr").attr("align","center");

    $("#add_photo_text_button").click(function(){       

        var _len = $("#add_photo_text tr").length;        

        $("#add_photo_text").append("<tr id="+_len+" align='center'>"

                            +"<td>"+_len+"</td>"

                            +"<td><input type='text' name='subject[body_data][][content]' id='desc"+_len+"' /></td>"

                            +"<td><input type='file' name='subject[body_data][][photo]' id='desc"+_len+"' /></td>"

                            +"<td><a href=\'#\' onclick=\'deltr("+_len+")\'>删除</a></td>"

                        +"</tr>");            

    })    

})

var deltr =function(index)

{

    var _len = $("#add_photo_text tr").length;

    $("tr[id='"+index+"']").remove();

    for(var i=index+1,j=_len;i<j;i++)

    {

        var nextTxtVal = $("#desc"+i).val();

        $("tr[id=\'"+i+"\']")

            .replaceWith("<tr id="+(i-1)+" align='center'>"

                            +"<td>"+(i-1)+"</td>"

                            +"<td><input type='text' name='subject[body_data][][content]' value='"+nextTxtVal+"' id='desc"+(i-1)+"'/></td>"

                            +"<td><input type='file' name='subject[body_data][][photo]' value='"+nextTxtVal+"' id='desc"+(i-1)+"'/></td>"

                            +"<td><a href=\'#\' onclick=\'deltr("+(i-1)+")\'>删除</a></td>"

                        +"</tr>");

    }    

    

controller:

 class Manage::SubjectsController < ManageController

  def index

    @q = Subject.ransack(params[:q])

    @subjects = @q.result.order(id: :desc).page(params[:page])

  end

  def create

    @subject = Subject.create(subject_params)

    if @subject.save

      redirect_to manage_subjects_path

    end

  end

  def new

    @subject = Subject.new

  end

  def edit

    @subject = Subject.find(params[:id])

    @rooms_subjects = @subject.rooms.all

  end

  def destroy

    Subject.find_by(id: params[:id]).delete

    redirect_to manage_subjects_path

  end

  def show

    @subject = Subject.find(params[:id])

  end

  def update

    @subject = Subject.find(params[:id])

    if @subject.update(subject_params)

      redirect_to manage_subjects_path

    end

  end

  def delete_room

    @subject = Subject.find(params[:id])

    @subject.rooms_subjects.find_by(room_id: params[:room_id]).delete

    redirect_to :back

  end

  private

    def subject_params

      params.require(:subject).permit(

        :user_id, :title, :description, :subject_type, :position, :status, :photo,

        body_data: [:content, :photo, :origin_url, :medium_url, :width, :height]

      )

    end

end

model:

class
4000
Subject < ActiveRecord::Base

  belongs_to :user

  has_many :rooms_subjects

  has_many :rooms, through: :rooms_subjects

  has_many :photos, as: :content

    # body: [{type: "text", content: "Hello world!~~~"},

  # {type: "photo", width: 300, height: 200, origin_url: "", medium_url: ""}]

  store :data, accessors: [:body]

  SubjectType = %w(Romance Classical Pink Fashion Gent)

  STATUS = %w(pending depending)

  def photos

    self.photos.where.not(position: 9999)

  end

  def photo

    Photo.where(content_id: self.id, content_type: self.class.name, position: 9999).order(id: :desc).first

  end

  def web_thumb_url

    "http://cdn.a0.bnbtrip.com/assets/images/web/2016/02/landing2.jpg"

  end

  def photo=(image)

    photo = self.photo

    if photo.present?

      photo.update(image: image)

    else

      Photo.create(content_id: self.id, content_type: self.class.name, image: image, position: 9999)

    end

  end

  def body_data=(params)

    new_body = []

    if params.present?

      params.each do |f|

        if f["content"].present?

          new_body << {type: "text", content: f[:content]}

        else

          if f["photo"].present?

            photo = Photo.create(content_id: self.id, content_type: self.class.name, image: f["photo"])

            new_body << {type: "photo", width: photo.width, height: photo.height, origin_url: photo.image_url, medium_url: photo.small_url}

          elsif f["origin_url"].present?

            new_body << {type: "photo", width: f["width"], height: f["height"], origin_url: f["origin_url"], medium_url: f["medium_url"]}

          end

        end

      end

    end

    self.update(body: new_body)

  end

end

view:

    <% if @subject.body.present? %>

      <% i = 0 %>

        <% @subject.body.each do |f|%>

          <tr>

              <td>

                <%= i += 1 %>

              </td>

              <td>

                <input type="text" name="subject[body_data][][content]" value="<%= f[:content] %>"></input>

              </td>

              <td>

                <input type="hidden" name="subject[body_data][][origin_url]" value="<%= f[:origin_url] %>"></input>

                <input type="hidden" name="subject[body_data][][medium_url]" value="<%= f[:medium_url] %>"></input>

                <input type="hidden" name="subject[body_data][][width]" value="<%= f[:width] %>"></input>

                <input type="hidden" name="subject[body_data][][height]" value="<%= f[:height] %>"></input>

                <%= image_tag(f[:medium_url]) if f[:medium_url] %>

                <input type="file" name="subject[body_data][][photo]"></input>

              </td>

              <td>

                <a href="#" class="delete_photo_text_button">删除</a>

              </td>

          </tr>

      <% end %>

    <% end %>