如何在 rails 视图上显示错误消息?
[英] How to show error message on rails views?
本文介绍了如何在 rails 视图上显示错误消息?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是 rails 的新手，想对 form 字段应用验证.
myviewsnew.html.erb
<%= form_for :simulation, url: simulations_path do |f|％＞<div class="form-group"><%= f.label :Row %><div class="row"><div class="col-sm-2"><%= f.text_field :row, class: 'form-control' %>
.....
模拟.rb
类模拟{ :in =>1..25, :message =>'该行必须在 1 到 25 之间' }结尾
simulation_controller.rb
class SimulationsController <应用控制器定义索引@simulations = Simulation.all结尾定义新结尾定义创建@simulation = Simulation.new(simulation_params)@simulation.save重定向到@simulation结尾私人的def Simulation_paramsparams.require(:simulation).permit(:row)结尾
我想检查模型类中 row 字段的整数范围，如果不在范围内则返回错误消息.我可以检查上述代码的范围，但无法返回错误消息
提前致谢
解决方案
关键是您使用的是模型表单，该表单显示 ActiveRecord 模型实例的属性.控制器的创建操作 将负责一些验证(您可以添加更多验证).
控制器重新渲染 new 模型保存失败时的视图
更改您的控制器，如下所示:
def new@simulation = Simulation.new结尾定义创建@simulation = Simulation.new(simulation_params)如果@simulation.save重定向到动作:'索引'别的呈现新"结尾结尾
当模型实例无法保存时(@simulation.save 返回 false)，则重新渲染 new 视图.
new 视图显示来自未能保存模型的错误消息
然后在您的 new 视图中，如果存在错误，您可以将它们全部打印出来，如下所示.
<%= form_for @simulation, as: :simulation, url: simulations_path do |f|％＞<% if @simulation.errors.any?％＞<ul><% @simulation.errors.full_messages.each do |message|％＞<li><%=消息%></li><%结束%><%结束%><div class="form-group"><%= f.label :Row %><div class="row"><div class="col-sm-2"><%= f.text_field :row, class: 'form-control' %>
<%结束%>
这里的重要部分是您正在检查模型实例是否有任何错误，然后将它们打印出来:
<% if @simulation.errors.any?％＞<%=@simulation.errors.full_messages %><%结束%>
I am newbie in rails and want to apply validation on form fields.
myviewsnew.html.erb
<%= form_for :simulation, url: simulations_path do |f| %>
<div class="form-group">
<%= f.label :Row %>
<div class="row">
<div class="col-sm-2">
<%= f.text_field :row, class: 'form-control' %>
</div>
</div>
</div>
.....
Simulation.rb
class Simulation < ActiveRecord::Base
belongs_to :user
validates :row, :inclusion => { :in => 1..25, :message => 'The row must be between 1 and 25' }
end
simulation_controller.rb
class SimulationsController < ApplicationController
def index
@simulations = Simulation.all
end
def new
end
def create
@simulation = Simulation.new(simulation_params)
@simulation.save
redirect_to @simulation
end
private
def simulation_params
params.require(:simulation).permit(:row)
end
I want to check the integer range of row field in model class and return the error message if it's not in the range. I can check the range from above code but not able to return the error message
Thanks in advance
解决方案
The key is that you are using a model form, a form that displays the attributes for an instance of an ActiveRecord model. The create action of the controller will take care of some validation (and you can add more validation).
Controller re-renders new View when model fails to save
Change your controller like below:
def new
@simulation = Simulation.new
end
def create
@simulation = Simulation.new(simulation_params)
if @simulation.save
redirect_to action: 'index'
else
render 'new'
end
end
When the model instance fails to save (@simulation.save returns false), then the new view is re-rendered.
new View displays error messages from the model that failed to save
Then within your new view, if there exists an error, you can print them all like below.
<%= form_for @simulation, as: :simulation, url: simulations_path do |f| %>
<% if @simulation.errors.any? %>
<ul>
<% @simulation.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
<% end %>
<div class="form-group">
<%= f.label :Row %>
<div class="row">
<div class="col-sm-2">
<%= f.text_field :row, class: 'form-control' %>
</div>
</div>
</div>
<% end %>
The important part here is that you're checking whether the model instance has any errors and then printing them out:
<% if @simulation.errors.any? %>
<%= @simulation.errors.full_messages %>
<% end %>
这篇关于如何在 rails 视图上显示错误消息?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
