Styling form error message - bootstrap/rails

Question

The error messages for my rails form look terrible with bootstrap. Does anyone know a solution for better (nice looking) error messages? I use Rails and Bootstrap.

My fo

Answer 1

I've create a custom initializer to have each field having its own errors below it

# app/config/initializers/bootstrap_form_errors_customizer.rb

ActionView::Base.field_error_proc = proc do |html_tag, instance|
  is_label_tag = html_tag =~ /^<label/
  class_attr_index = html_tag.index 'class="' 

  def format_error_message_to_html_list(error_msg)
    html_list_errors = "<ul></ul>"
    if error_msg.is_a?(Array)
      error_msg.each do |msg|
        html_list_errors.insert(-6,"<li>#{msg}</li>")
      end
    else 
      html_list_errors.insert(-6,"<li>#{msg}</li>")
    end
    html_list_errors
  end

  invalid_div =
    "<div class='invalid-feedback'>#{format_error_message_to_html_list(instance.error_message)}</div>"

  
  if class_attr_index && !is_label_tag
    html_tag.insert(class_attr_index + 7, 'is-invalid ')
    html_tag + invalid_div.html_safe
  elsif !class_attr_index && !is_label_tag
    html_tag.insert(html_tag.index('>'), ' class="is-invalid"')
    html_tag + invalid_div.html_safe
  else
    html_tag.html_safe
  end
end

Answer 2

A little late I realize, but I just ran into this today with Rails 4 and Bootstrap 3, I ended up making a view helper to display errors using a panel:

Rails 4 / Bootstrap 3

def errors_for(object)
    if object.errors.any?
        content_tag(:div, class: "panel panel-danger") do
            concat(content_tag(:div, class: "panel-heading") do
                concat(content_tag(:h4, class: "panel-title") do
                    concat "#{pluralize(object.errors.count, "error")} prohibited this #{object.class.name.downcase} from being saved:"
                end)
            end)
            concat(content_tag(:div, class: "panel-body") do
                concat(content_tag(:ul) do
                    object.errors.full_messages.each do |msg|
                        concat content_tag(:li, msg)
                    end
                end)
            end)
        end
    end
end

Rails 4 / Bootstrap 4 Beta

def errors_for(object)
    if object.errors.any?
        content_tag(:div, class: "card border-danger") do
            concat(content_tag(:div, class: "card-header bg-danger text-white") do
                concat "#{pluralize(object.errors.count, "error")} prohibited this #{object.class.name.downcase} from being saved:"
            end)
            concat(content_tag(:div, class: "card-body") do
                concat(content_tag(:ul, class: 'mb-0') do
                    object.errors.full_messages.each do |msg|
                        concat content_tag(:li, msg)
                    end
                end)
            end)
        end
    end
end

Rails 4 / Bootstrap 4 Beta List Group Variation

def errors_for(object)
    if object.errors.any?
        content_tag(:div, class: "card border-danger") do
            concat(content_tag(:div, class: "card-header bg-danger text-white") do
                concat "#{pluralize(object.errors.count, "error")} prohibited this #{object.class.name.downcase} from being saved:"
            end)
            concat(content_tag(:ul, class: 'mb-0 list-group list-group-flush') do
                object.errors.full_messages.each do |msg|
                    concat content_tag(:li, msg, class: 'list-group-item')
                end
            end)
        end
    end
end

I dropped it in application_helper and call it in my form views

<%= errors_for(@user) %>

Maybe someone will stumble upon this and find it useful.

Answer 3

I have implemented Rabbott's view helper in Rails 5 and Bootstrap 4:

def errors_for(object)
    if object.errors.any?
      content_tag(:div, class: 'card text-white bg-danger mb-3') do
        concat(content_tag(:div, class: 'card-header') do
          concat(content_tag(:h4) do
            concat "#{pluralize(object.errors.count, 'error')} prohibited this #{object.class.name.downcase} from being saved:"
          end)
        end)
        concat(content_tag(:div, class: 'card-body') do
          concat(content_tag(:ul) do
            object.errors.full_messages.each do |msg|
              concat content_tag(:li, msg)
            end
          end)
        end)
      end
    end
  end

And it looks like this:

Answer 4

Take a look at how Michael Hartl does it in railstutorial.

And thats the used css:

#error_explanation {
  color: #f00;
  ul {
    list-style: none;
    margin: 0 0 18px 0;
  }
}

.field_with_errors {
  @extend .control-group;
  @extend .error;
 }

He describes everything here.

If you also want the little star at the beginning of every line you have to include it in your form:

     <div id="error_explanation">
        <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>
        <ul>
          <% @user.errors.full_messages.each do |msg| %>
            <li> * <%= msg %></li>    <--- insert here
          <% end %>
        </ul>
     </div>
      ...

Answer 5

Another variation with SCSS only

#error_explanation{
  background: #f23551;
  color: #fff;
  border-radius: 4px;
  margin-bottom: 20px;
  h2{
    padding: 20px;
    margin: 0;
    font-size: 20px;
  }
  ul{
    background: #fff;
    color: #e5324a;
    border: 1px solid #F23551;
    margin: 0;
    list-style: none;
    padding: 14px 0;
    li{
      padding: 4px 20px;
      &:before {
        content: '×';
        font-weight: bold;
        font-size: 20px;
        margin-right: 10px;
      }
    }
  }
}

Answer 6

Just in case someone stumbles here and is using Bootstrap 4 alpha with rails 5 and bootstrap_form_for gem. I use:

<div class="form-group">
  <%= f.alert_message "Please fix the errors below." %>
</div>

which looks really nice.