Question

I have a very simple sign_in page for a devise user. Upon submitting incorrect data, the log shows a ‘401 Unauthorized’ and redirects me back to the sign_in page. I couldn’t figure out a way to show error messages to the user.

I looked at devise::sessions_controller#create which is as follows,

 # POST /resource/sign_in
  def create
    resource = warden.authenticate!(auth_options)
    set_flash_message(:notice, :signed_in) if is_navigational_format?
    sign_in(resource_name, resource)
    respond_with resource, :location => after_sign_in_path_for(resource)
  end

  def auth_options
    { :scope => resource_name, :recall => "#{controller_path}#new" }
  end  

The flow gets interrupted at warden.authenticate in case of a failed authentication and the user get redirected to the ‘new’ which is the sign_in page.

I just need to show the user a invalid_credentials tooltip/flash_message. So I did it by modifying :recall => "#{controller_path}#handle_create_fail" (look at auth_options) which calls handle_create_fails when authentication fails, inside which I setup the error messages.

I am not sure if I overlooked something that devise already provides.

How can I handle this better?

Answer 1

‘devise’ stores error messages in rails ‘flash’, using flash[:notice] for success messages and flash[:alert] for problems.

Here’s this from the devise documentation:

Remember that Devise uses flash messages to let users know if sign in
was successful or failed. Devise expects your application to call
“flash[:notice]” and “flash[:alert]” as appropriate.

This means that in your view file (or more generally in your application layout file) you should include something similar to these lines:

<%= content_tag(:div, flash[:error], :id => "flash_error") if flash[:error] %>
<%= content_tag(:div, flash[:notice], :id => "flash_notice") if flash[:notice] %>
<%= content_tag(:div, flash[:alert], :id => "flash_alert") if flash[:alert] %>

Here are some similar questions/answers:

Rails – Devise – Error messages when signing in?

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