validates :presence vs validates_presence_of using rails 3

Question

I have a couple of simple models that are associated like so:

MODELS

class Task < ActiveRecord::Base
  belongs_to :user
  validates :name, :presence => true, :message => 'Name cannot be blank, Task not saved'
end

class User < ActiveRecord::Base
  has_many :tasks
end

VIEW has a call in it like so: user.tasks <-- then I loop through the tasks

The Issue:

In the task model --

when I use:

validates :name, :presence => true ,  :message => 'Name cannot be blank, Task not saved'

I get a 500 error:

ActionView::Template::Error (uninitialized constant User::Task):
NameError in View file

when I use:

validates_presence_of :name

Everything works.

I thought the both validates methods above where the same...is the issue have to do with associations and how validation tie into associated models. I have a hunch that something is going on with the way things are associated, but it is just a hunch.

Any help will be appreciated. Thank very much.

Answer 1

When you use the newer validates :name format, you can put multiple validations in one line rather than having to have multiple lines for each type of validation. Because of this, when Rails hits your :message parameter, it thinks it's a validation method rather than a message associated with :presence. Try this instead:

validates :name, :presence => {:message => 'Name cannot be blank, Task not saved'}

Also, depending on how you display your errors, this error may actually show up as 'Name Name cannot be....'; if so, you'll want to set the message to just 'cannot be blank, Task not saved'.