無法在控制器中讀取參數，Ruby on Rails

Question

在我的Ruby on Rails項目中，我希望（取決於您單擊哪個鏈接）創建的對象具有不同的編號。

我有一本書和章模型，章屬於書。 Chapter有一個叫做「place」的整數屬性。

目前，當我點擊鏈接：http://localhost:3000/1/chapters/new/ 它呈現new.html.erb頁面，一切工作正常。現在

，我添加了一個新的途徑：

chapterchapter GET /:book_id/chapters/new(.:format)/:place  chapters#new 

此鏈接

<%= link_to "Contribute", chapterchapter_path(@book, 5) %> 

將導致：

http://localhost:3000/1/chapters/new/5 

在我的控制，我有這行代碼：

def new 
    @chapter = Chapter.new 
    end 

    def create 
    @chapter = Chapter.new(chapter_params) 
    @chapter.book_id = @book.id 
    @chapter.user_id = current_user.id 
    @chapter.place = params[:place] 

我的問題是，這行代碼：@chapter.place = params[:place]不起作用，因爲創建的章節返回nil for chapter.place。我需要做什麼，@ chapter.place讀取參數：place？任何建議？

編輯：我的數據庫模式：

ActiveRecord::Schema.define(version: 20160117110001) do 

    create_table "books", force: :cascade do |t| 
    t.string "title" 
    t.text  "description" 
    t.integer "maxnumchapt" 
    t.datetime "created_at", null: false 
    t.datetime "updated_at", null: false 
    t.integer "min_length" 
    t.integer "max_length" 
    t.integer "user_id" 
    end 

    create_table "chapters", force: :cascade do |t| 
    t.string "chaptertitle" 
    t.text  "chaptercontent" 
    t.string "author" 
    t.datetime "created_at",  null: false 
    t.datetime "updated_at",  null: false 
    t.integer "book_id" 
    t.integer "user_id" 
    t.integer "place" 
    end 

    create_table "users", force: :cascade do |t| 
    t.string "email",     default: "", null: false 
    t.string "encrypted_password",  default: "", null: false 
    t.string "reset_password_token" 
    t.datetime "reset_password_sent_at" 
    t.datetime "remember_created_at" 
    t.integer "sign_in_count",   default: 0, null: false 
    t.datetime "current_sign_in_at" 
    t.datetime "last_sign_in_at" 
    t.string "current_sign_in_ip" 
    t.string "last_sign_in_ip" 
    t.datetime "created_at",       null: false 
    t.datetime "updated_at",       null: false 
    end 

    add_index "users", ["email"], name: "index_users_on_email", unique: true 
    add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true 

end 

編輯2：看來，只要我按下提交鍵，參數的地方迷路：

Started GET "/30/chapters/new/2" for 127.0.0.1 at 2016-01-17 23:39:07 +0100 
Processing by ChaptersController#new as HTML 
    Parameters: {"book_id"=>"30", "place"=>"2"} 
    Book Load (0.1ms) SELECT "books".* FROM "books" WHERE "books"."id" = ? LIMIT 1 [["id", 30]] 
    Rendered chapters/new.html.erb within layouts/application (36.8ms) 
    User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1 [["id", 1]] 
Completed 200 OK in 55ms (Views: 53.2ms | ActiveRecord: 0.2ms) 


Started POST "/books/30/chapters" for 127.0.0.1 at 2016-01-17 23:39:16 +0100 
Processing by ChaptersController#create as HTML 
    Parameters: {"utf8"=>"✓", "authenticity_token"=>"566kl+qg5otw1FGVh0uIoytGxFlF5qp0c4Ws41JhtzSzhqWuND997PltE7LXGiIvEC7A/uqCtg8WMdnNndN/Rg==", "chapter"=>{"chaptertitle"=>"fadfadfaf", "chaptercontent"=>"afddfaf", "author"=>"adfadfa"}, "commit"=>"Create Chapter", "book_id"=>"30"} 
    Book Load (0.1ms) SELECT "books".* FROM "books" WHERE "books"."id" = ? LIMIT 1 [["id", 30]] 
    User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1 [["id", 1]] 

編輯3：章節/ new.html

<%= simple_form_for([@book, @book.chapters.build]) do |f| %> 
    <%= f.input :chaptertitle %> 
    Mininmum amount of characters: <%= @book.min_length %> Maximum amount of characters: <%= @book.max_length %> 
    <div class="counting" ><%= f.input :chaptercontent %>Characters: <span class="count"></span></div><br> 
    <%= f.input :author %> 
    <%= f.button :submit %> 
<% end %> 

<script> 

    $(document).ready(function(){ 

    var choosingbar = function(event){ 
     $(event.target).parents(".counting").children(".count").text($(event.target).val().length); 
    }; 

    $(".counting textarea").keyup(choosingbar); 
    }); 

</script> 

Answer 1

你應該有一個隱藏字段中的表格用於捕捉params[:place]並將其發送回create的動作。

<%= simple_form_for([@book, @book.chapters.build]) do |f| %> 
    <%= f.input :chaptertitle %> 
    Mininmum amount of characters: <%= @book.min_length %> Maximum amount of characters: <%= @book.max_length %> 
    <div class="counting" ><%= f.input :chaptercontent %>Characters: <span class="count"></span></div><br> 
    <%= f.input :author %> 
    <%= f.input :place, :as => :hidden, :input_html => { :value => params[:place] } %> 
    <%= f.button :submit %> 
<% end %> 

現在在創建操作訪問它像@chapter.place = params[:chapter][:place]