Question

My rails app serves as API for my android app.
I’m wondering when the request encounters any problem, is there a way to detect which error it is on the server side and return with a specific code?

For example, in my users_controller.rb,

if @user.save
  respond_with(@user)
else  
  render json: {errors: @user.errors.full_messages}
end

The output looks like:

{"errors":["Username can't be blank","Password is too short (minimum is 6 characters)","Email has already been taken"]}

How can I check whether it is because of an error of email or an error of password in the controller? Thanks!

Answer 1

• go to rails console
• type: u = User.new
• type: u.valid?
• type: u.errors

Examine the result. You should be able to figure it out.

Alternatively read the documentation: http://api.rubyonrails.org/classes/ActiveModel/Errors.html

Hint: errors is just an OrderedHash object with some additional convenience methods, like full_messages. It has all the information that you are looking for, just not in full_messages.