validating presence of email address (can't be blank)- Ruby on Rails

Pretty new at all this. I have a simple form for users to enter a couple pieces of information and then input their email address and push the submit button. I want to make it mandatory that they have to fill out their email address in order to pus开发者_JAVA百科h the submit button. If they don't fill out their email address they should get an error message on the email box that says the email can't be blank. I know this is super simple but I need exact help on where to put what code. I've been researching this all night and know that part of the code should go in the application_controller and other should go in the html file where the actual text_field:email is. I'd be grateful if someone could clearly tell me what the necessary steps are for doing this. Thanks!

It should go in your model. Add this:

class Model < ActiveRecord::Base 
 validates_presence_of :email
end 

Check this link for more info: http://guides.rails.info/activerecord_validations_callbacks.html#validates-presence-of

In Rails 2, which I would assume you are using, validations go in the model. Which is located in $Rails_app_directory/app/model/$Classname.rb

In order to add ActiveRecord validations you can use the line

validates_presence_of :email_address

You should also consider using Rails to generate a confirmation field and filtering out ill-formatted email addresses. You could accomplish the former with:

validates_confirmation_of :email_address

with this, all you need to add to your form is a text_field for :email_address_confirmation

and the latter with a regular expression such as:

validates_format_of :email_address, :with => /\A[\w\.%\+\-]+@(?:[A-Z0-9\-]+\.)+(?:[A-Z]{2}|com|org|net|edu|gov|mil|biz|info|mobi|name|aero|jobs|museum)\z/i

From snipplr, place in your model

validates_format_of     :email,
                        :with       => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i,
                        :message    => 'email must be valid'