从 rails 中的单个表单提交提交多个表条目

Question

我正在尝试为我的钓鱼俱乐部会议制作一张出席表，其中显示所有活跃成员并允许您在他们的名字旁边放置一个复选框，以记录他们是否参加了特定锦标赛的会议。我创建了一个“会议”脚手架，并在 _form 中列出了所有活跃成员，并允许用户勾选该成员是否参加了所选锦标赛的会议。但是，我在将哈希数组传递给我的 meetings_controller 时遇到了问题，而且我很困惑。

我读了很多文章，但我的设计基于这篇文章：Submit array of hashes with rails

这篇文章没有显示 create 方法中的内容，所以我有这个......

会议控制器：

def create
    # puts " OUTPUT TEXT: #{params} " 
    
    @meeting = params[:meetings][:meetings]
    
    @meeting.each do |m|

    #If there is no attendance key, its nil. Make it false
    # if !m[:meeting].has_key?("attendance")
    #     m[:meeting].attendance = false
    # end
     
      puts "OUTPUT TEXT: #{m[:meeting]}" # OUTPUT TEXT: {"member_id"=>"1", "tournament_id"=>"2", "attendance"=>"1"}
     
      @meeting = Meeting.new(member_id: m[:meeting][:member_id], tournament_id: m[:meeting][:tournament_id], attendance: m[:meeting][:attendance])
     
   end
    respond_to do |format|
      if @meeting.save
        format.html { redirect_to @meeting, notice: "Meeting was successfully created." }
        format.json { render :show, status: :created, location: @meeting }
      else
        format.html { render :new, status: :unprocessable_entity }
        format.json { render json: @meeting.errors, status: :unprocessable_entity }
      end
    end
  end

_form 输入：（基于上面链接的文章）

<% Member.where(active: true).each do |member| %>
   
   <tr>
    <td> <%= member.full_name %> </td>
    
    <input multiple="multiple" value=<%=member.id %> type="hidden" name="meetings[meetings][]meeting[member_id]" />


    <input multiple="multiple" value=<%=@tournament.id %> type="hidden" name="meetings[meetings][]meeting[tournament_id]" />
    

    <td><input type="checkbox" value="1" name="meetings[meetings][]meeting[attendance]" /></td>
  </tr>
 <% end %> 

当我点击提交表格时，它只是将我带到显示页面，其中只有这个显示在空白页面上......

{"controller"=>"meetings", "action"=>"show", "id"=>"18"}

即使我在 show 方法中有重定向行

def show
    redirect_to meetings_path
end

我花了很多时间阅读，并进行反复试验以使其发挥作用。希望stackoverflow大神们帮忙。

Answer 1

在控制器中，当您循环通过会议参数时，Meeting 不会保存到数据库并且 @meeting 变量会被覆盖，直到数组中的最后一项...

@meeting.each do |m|     
  @meeting = Meeting.new(member_id: m[:meeting][:member_id], tournament_id: m[:meeting][:tournament_id], attendance: m[:meeting][:attendance])
end

……这就是被拯救的人。

if @meeting.save

也不确定您的 show 操作发生了什么，保存后不要重定向到它。

在 Rails 表单中使用数组有点不确定。但它就在这里。

控制器：

# params - submitted params from the form
#          { "authenticity_token"=>"[FILTERED]", 
#             "meetings"=>[
#               { "member_id"=>"1", "tournament_id"=>"1", attendance"=>"1" },
#               ...
#              ],
#            "commit"=>"Save"
#          }

# POST /meetings
def create
  @meetings = meetings_params.map do |param|
    Meeting.create_with(attendance: param[:attendance])
      .find_or_create_by(member_id: param[:member_id], tournament_id: param[:tournament_id])
  end
  respond_to do |format|
    if @meetings.detect{|m| m.id == nil }  # id=nil if any meetings didn't save
      # FIXME: @tournament not initialized here
      format.html { render :new, status: :unprocessable_entity }
    else
      format.html { redirect_to meetings_url, notice: "Meetings were created." }
    end
  end
end

# Returns array 
# [{member_id: 1, tournament_id: 1, attendance: 1}, ...]
def meetings_params
  params.permit(meetings: [:member_id, :tournament_id, :attendance]).require(:meetings)
end

形式：

<%= form_with url: "/meetings" do |f| %>
  <% Member.where(active: true).each do |member| %>
    <%# TODO: if meeting doesn't save, there is no error to show %>
    <%= text_field_tag "meetings[][member_id]",     member.id %>
    <%= text_field_tag "meetings[][tournament_id]", @tournament.id %>
    <%= check_box_tag  "meetings[][attendance]",    Meeting.find_by(member: member, tournament: @tournament)&.attendance %>
  <% end %>
  <%= f.submit %>
<% end %>

或者使用 fields_for 助手：

<%= form_with url: "/meetings" do |f| %>
  <% Member.where(active: true).each do |member| %>
    <%#                            this nil does the [] thing %>
    <%#                                     |                 %>
    <%= fields_for "meetings", nil, index: nil do |ff| %>
      <%= ff.number_field "member_id",     value: member.id %>
      <%= ff.hidden_field "tournament_id", value: @tournament.id %>
      <%= ff.check_box    "attendance",    value: Meeting.find_by(member: member, tournament: @tournament)&.attendance %>
    <% end %>
  <% end %>
  <%= f.submit %>
<% end %>

更新

可以这么说，以上所有内容确实是违反轨道的。这是我想出的让它超级简单的方法：

我们需要一个Attendance表来跟踪每个Meeting的每个成员的出席情况：

# db/migrate/20221122034503_create_attendances.rb 
class CreateAttendances < ActiveRecord::Migration[7.0]
  def change
    create_table :attendances do |t|
      t.boolean :attended
      t.references :meeting, null: false, foreign_key: true
      t.references :member,  null: false, foreign_key: true
    end
  end
end

# app/models/attendance.rb 
class Attendance < ApplicationRecord
  belongs_to :meeting
  belongs_to :member
end

# app/models/meeting.rb
class Meeting < ApplicationRecord
  has_many :attendances
  # NOTE: let rails take care of nested attendances from the form
  accepts_nested_attributes_for :attendances
end

MeetingsController 是默认脚手架：

bin/rails g scaffold_controller meeting

只需更新new 操作：

# app/controllers/meetings_controller.rb
def new
  @meeting = Meeting.new
  # NOTE: build a list of attendances for the form to render
  Member.where(active: true).each do |member|
    @meeting.attendances.build(member: member)
  end
end

表格现在超级简单：

<!-- app/views/meetings/_form.html.erb -->
<%= form_with model: @meeting do |f| %>
  <%= f.fields_for :attendances do |ff| %>
    <%= ff.number_field :member_id %>
    <%= ff.check_box :attended %>
  <% end %>
  <%= f.submit %>
<% end %>

create 和update 自己工作。