How to Highlight Fields on Rails Validation Errors

问题:

How do you display form field highlighting for fields that fail validation errors in Rails 3.1? I know that scaffolding automatically generates the css and controller code to handle this, but I was wondering if there was a way to generate that manually. I have already implemented the string display of error messages through: @user.errors.full_messages.each...etc, but I can't get the fields to become highlighted in red. Any ideas?

Thanks.

回答1:

Assuming you have an error class for fields in your CSS file:

    "error" %>      

Is this what you want?

Extra: here's a section about customizing default ActiveRecord validations CSS.

Edit: (about extra ifs)

# app/helpers/application_helper.rb  def field_class(resource, field_name)   if resource.errors[field_name]     return "error".html_safe   else     return "".html_safe   end end 

And then:

# in your view   field_class(@user, :name) %>  field_class(@user, :password) %> [...] 

(I may have make a mistake in there - I'm writing on a phone - but you get the general idea. You can code this in number of ways = infinity, so do it the way you like...)

回答2:

Rails now have a nice trick up its sleeve..When an error occurs rails put a div with a class .field_with_errors around the error fields. So now you can target that class and add styling.

To focus on the input you can do

.field_with_errors input{   border: 1px solid red !important; } 

this css will put a nice red line around the input element while important! will overwrite any existing styles.

回答3:

I had to do this (resource.errors[field_name].length > 0) to get it to work:

def field_class(resource, field_name) if resource.errors[field_name].length > 0 return " custom_error1 ".html_safe else return "".html_safe end end

文章来源: How to Highlight Fields on Rails Validation Errors