在我的应用程序中,一系列由许多书籍组成。系列的“显示”页面允许用户查看系列中的所有书籍,并使用表单向系列添加新书。
“显示”页面上列出的每本书都有一个指向该书的“编辑”页面的链接。编辑页面包含用于初始添加书籍的相同表单。编辑图书时,表格应自动填写图书现有信息。
如何配置我的form_with
标签,以便它可以创建新书并编辑现有书籍(自动填写编辑表格)?我尝试了以下配置,但它们要么打破编辑页面要么打破显示页面:
<%= form_with(model: [ @series, @series.books.build ], local: true) do |form| %>
打破书籍编辑页面
错误:没有错误,但表单不会自动填充数据<%= form_with(model: @book, url: series_book_path, local: true) do |form| %>
打破系列显示页面
错误:No route matches {:action=>"show", :controller=>"books", :id=>"6"}, missing required keys: [series_id]
<%= form_with(model: [:series, @book], local: true) do |form| %>
打破系列显示页面
错误:Undefined method 'model_name' for nil:NilClass
<%= form_with(model: [@series, @series.books.find(@book.id)], local: true) do |form| %>
打破系列显示页面
错误:undefined method 'id' for nil:NilClass
<%= form_with(model: @book, url: [@series, @book], local: true) do |form| %>
在系列展示页面上提交新书时中断
错误:No route matches [POST] "/series/6"
下面是相关代码的精简部分,以及它们在我当前的GitHub存储库中存在的位置的链接。
resources :series do
resources :books
end
class Book < ApplicationRecord
belongs_to :series
end
class Series < ApplicationRecord
has_many :books, dependent: :destroy
end
create_table "books", force: :cascade do |t|
t.integer "series_number"
t.integer "year_published"
t.integer "series_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.index ["series_id"], name: "index_books_on_series_id"
end
create_table "series", force: :cascade do |t|
t.string "title"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
app/views/series/show.html.erb
<%= render @series.books %>
<%= render 'books/form' %>
app/views/books/_book.html.erb
<%= link_to 'Edit', edit_series_book_path(book.series, book) %>
<%= render 'form' %>
app/views/books/_form.html.erb
<%= form_with(model: @book, url: [@series, @book], local: true) do |form| %>
<%= form.label :series_number %>
<%= form.number_field :series_number %>
<%= form.label :year_published %>
<%= form.number_field :year_published %>
<% end %>
app/controllers/books_controller.rb
class BooksController < ApplicationController
def index
@books = Book.all
end
def show
@book = Book.find(params[:id])
end
def new
@book = Book.new
end
def edit
@series = Series.find(params[:series_id])
@book = @series.books.find(params[:id])
end
def create
@series = Series.find(params[:series_id])
@book = @series.books.create(book_params)
redirect_to series_path(@series)
end
def destroy
@series = Series.find(params[:series_id])
@book = @series.books.find(params[:id])
@book.destroy
redirect_to series_path(@series)
end
private
def book_params
params.require(:book).permit(:year_published, :series_number)
end
end
Prefix Verb URI Pattern Controller#Action
articles GET /articles(.:format) articles#index
POST /articles(.:format) articles#create
new_article GET /articles/new(.:format) articles#new
edit_article GET /articles/:id/edit(.:format) articles#edit
article GET /articles/:id(.:format) articles#show
PATCH /articles/:id(.:format) articles#update
PUT /articles/:id(.:format) articles#update
DELETE /articles/:id(.:format) articles#destroy
series_books GET /series/:series_id/books(.:format) books#index
POST /series/:series_id/books(.:format) books#create
new_series_book GET /series/:series_id/books/new(.:format) books#new
edit_series_book GET /series/:series_id/books/:id/edit(.:format) books#edit
series_book GET /series/:series_id/books/:id(.:format) books#show
PATCH /series/:series_id/books/:id(.:format) books#update
PUT /series/:series_id/books/:id(.:format) books#update
DELETE /series/:series_id/books/:id(.:format) books#destroy
series_index GET /series(.:format) series#index
POST /series(.:format) series#create
new_series GET /series/new(.:format) series#new
edit_series GET /series/:id/edit(.:format) series#edit
series GET /series/:id(.:format) series#show
PATCH /series/:id(.:format) series#update
PUT /series/:id(.:format) series#update
DELETE /series/:id(.:format) series#destroy
您可以将数组传递给表单以处理嵌套和“浅”路由:
<%= form_with(model: [@series, @book], local: true) do |form| %>
<% end %>
Rails压缩数组(删除nil值),因此如果@series
为零,则表单将回退到book_url(@book)
或books_url
。但是,您需要从控制器中正确设置@series
和@book
。
class SeriesController < ApplicationController
def show
@series = Series.find(params[:id])
@book = @series.books.new # used by the form
end
end
您可以使用local变量在视图中处理此问题:
# app/views/books/_form.html.erb
<%= form_with(model: model, local: true) do |form| %>
<% end %>
# app/views/books/edit.html.erb
<%= render 'form', locals: { model: [@series, @book] } %>
# app/views/series/show.html.erb
<%= render 'books/form', locals: { model: [@series, @series.book.new] } %>
您还可以在路线中使用shallow: true
选项,以避免嵌套成员路线(显示,编辑,更新,销毁):
resources :series do
resources :books, shallow: true
end
这将让你做到:
# app/views/books/edit.html.erb
<%= render 'form', model: @book %>
# app/views/books/_book.html.erb
<%= link_to 'Edit', edit_book_path(book) %>