Ruby on Rails表单错误未提供任何输出/不起作用

问题描述

大家好，我到处搜索了如何输出格式错误，但是没有运气。我尝试了在互联网上找到的几乎所有代码，但仍然无法正常工作。

这是我的一些文件：

view / books / new.html.erb

<div class="container">
  <h2>Create a new book</h2>
  <%= form_with model: @book,url: create_new_book_path do |f| %>
    <% if @book.errors.any? %>
      <ul>
        <% @book.errors.full_messages.each do |msg| %>
          <li><%= msg %></li>
        <% end %>
      </ul>
    <% end %>

    <div class="form-group row">
      <%= label_tag(:title,"Title:",class: "col-sm-2 col-form-label") %>
      <div class="col-sm-10">
        <%= f.text_field :title,class: "form-control" %>
      </div>
    </div>
    <div class="form-group row">
      <%= label_tag(:price,"Price:",class: "col-sm-2 col-form-label") %>
      <div class="col-sm-10">
        <%= f.text_field :price,class: "form-control" %>
      </div>
    </div>
    <div class="form-group row">
      <%= label_tag(:subject_id,"Subject:",class: "col-sm-2 col-form-label") %>
      <div class="col-sm-10">
        <%= f.collection_select :subject_id,@subjects,:id,:name,class: "form-control" %>
      </div>
    </div>
    <div class="form-group row">
      <%= label_tag(:description,"Book description:",class: "col-sm-2 col-form-label") %>
      <div class="col-sm-10">
        <%= f.text_area :description,class: "form-control" %>
      </div>
    </div>
    <%= submit_tag "Create book",class: "btn btn-success" %>

    <%= link_to "Cancel",books_path,class: "btn btn-danger" %>
  <% end %>
  <br/>
</div>

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
    @subjects = Subject.all
  end

  def create
    @book = Book.new(book_params)
  end

  def book_params
    params.require(:book).permit(:title,:price,:subject_id,:description)
  end

  def edit
    @book = Book.find(params[:id])
    @subjects = Subject.all
  end

  def update
    @book = Book.find(params[:id])
    if @book.update_attributes(book_params)
      redirect_to action: "index"
    else
      @subjects = Subject.all
      render action: "edit"
    end
  end

  def destroy
    Book.find(params[:id]).destroy
    redirect_to action: "index"
  end
end

routes.rb

  get 'books/new',to: 'books#new',as: 'new_book'
  post 'books/create',to: 'books#create',as: 'create_new_book'

view / layouts / application.html.erb

<main role="main">
  <%= yield %>
</main>

我真的不知道我要得到什么错误，感谢您的回答！

解决方法

尝试将它们放在这样的闪光灯中并在您的视图中呈现

  def create
    @book = Book.new
    if @book.update(book_params)
      flash[:notice] = 'success'
      redirect_to action: 'index'
    else
      flash[:alert] = @book.errors.full_messages.join(',')

      redirect_to action: 'index'
    end
  end

，然后在您的视图中呈现出类似的闪光

<% if flash[:notice]%>
  <span class='notice'><%= flash[:notice] %></span>
<% end %>
<% if flash[:alert]%>
  <span class='alert'><%= flash[:alert] %></span>
<% end %>