/ Ruby on Rails
/
method

error_message_on

error_message_on(object, method, prepend_text = "", append_text = "", css_class = "formError")
public

Returns a string containing the error message attached to the method on the object, if one exists. This error message is wrapped in a DIV tag, which can be specialized to include both a prepend_text and append_text to properly introduce the error and a css_class to style it accordingly. Examples (post has an error message "can’t be empty" on the title attribute): 

  <%= error_message_on "post", "title" %> =>
    <div class="formError">can't be empty</div>

  <%= error_message_on "post", "title", "Title simply ", " (or it won't work)", "inputError" %> =>
    <div class="inputError">Title simply can't be empty (or it won't work)</div>

1Note

Overriding the default div class="fieldWithErrors"

hosiawak ยท Aug 12, 20089 thanks

By default fields that are invalid are wrapped in:

<div class="fieldWithErrors">
<input type="text" name="blah">
</div>

To override and wrap in spans instead of divs place the following in your environment.rb:

ActionView::Base.field_error_proc = Proc.new { |html_tag, instance| "<span class=\\"fieldWithErrors\\">#{html_tag}</span>" }

or to not use wrapping at all:

ActionView::Base.field_error_proc = Proc.new { |html_tag, instance| "#{html_tag}" }