Rails - Apr 2006 - validation nightmare

Please help, I am really at a loss at how validation is supposed to work 
in rails.

Model contains

acts_as_tree

I want to force my NEW objects to have a parent
I do NOT want existing object to have a parent

so I only want to have parent_id on create, NOT on update.

I am trying this:

    def validate_on_create
      validates_presence_of :parent_id, :message => "You must specify a 
parent for this keyword."
    end


and I get:

undefined method `validates_presence_of'' for
#<Keyword:0xb774aba0>


The only time it works is if I remove validate_on_create, but then I can 
no longer update existing entries that do not have a parent!


this is driving me mad.

please help.

many thanks

Isabelle

-- 
Posted via http://www.ruby-forum.com/.

Isabelle wrote:
> Please help, I am really at a loss at how validation is supposed to work 
> in rails.
> 
> Model contains
> 
> acts_as_tree
> 
> I want to force my NEW objects to have a parent
> I do NOT want existing object to have a parent
> 
> so I only want to have parent_id on create, NOT on update.
> 
> I am trying this:
> 
>     def validate_on_create
>       validates_presence_of :parent_id, :message => "You must
specify a
> parent for this keyword."
>     end
> 
> 
> and I get:
> 
> undefined method `validates_presence_of'' for
#<Keyword:0xb774aba0>
> 
> 
> The only time it works is if I remove validate_on_create, but then I can 
> no longer update existing entries that do not have a parent!
> 
> 
> this is driving me mad.
> 
> please help.
> 
> many thanks
> 
> Isabelle
Hi,

maybe try

validates_presence_of :parent_id, :message => "You must specify a parent
for this keyword.", :on => :create

?
--
Agnieszka

-- 
Posted via http://www.ruby-forum.com/.

> validates_presence_of :parent_id, :message => "You must specify a
parent
> for this keyword.", :on => :create

of course!

many thanks.

-- 
Posted via http://www.ruby-forum.com/.

Isabelle wrote:
> 
>> validates_presence_of :parent_id, :message => "You must specify
a parent
>> for this keyword.", :on => :create
> 
> 
> of course!
> 
> many thanks.
replied too early.

your solution does not work if I want to do several verifications on 
create.
It also does not answer why I was getting the error.

So my problem remains.

This should work, but somehow it doesn''t:

def validate_on_create
  validates_presence_of :parent_id, :message => "message."
  # more methods here
end

returns:
undefined method `validates_presence_of'' for
#<Keyword:0xb774aba0>

-- 
Posted via http://www.ruby-forum.com/.

Hi Isabelle,

Isabelle wrote:

Just to check assumptions,  where does the code below live?  The model,
controller, or somewhere else?

Best regards,
Bill
> This should work, but somehow it doesn''t:
>
> def validate_on_create
>   validates_presence_of :parent_id, :message => "message."
>   # more methods here
> end
>
> returns:
> undefined method `validates_presence_of'' for
#<Keyword:0xb774aba0>

Isabelle wrote:
> Isabelle wrote:
>> 
>>> validates_presence_of :parent_id, :message => "You must
specify a parent
>>> for this keyword.", :on => :create
>> 
>> 
>> of course!
>> 
>> many thanks.
> 
> replied too early.
> 
> your solution does not work if I want to do several verifications on 
> create.
> It also does not answer why I was getting the error.
> 
> So my problem remains.
> 
> This should work, but somehow it doesn''t:
> 
> def validate_on_create
>   validates_presence_of :parent_id, :message => "message."
>   # more methods here
> end
> 
> returns:
> undefined method `validates_presence_of'' for
#<Keyword:0xb774aba0>
validates_presence_of is designed to be used on its own, not in a 
method--it''s a class method rather than an instance method.  If you
want
to make your own custom "validate_on_create", then use Ruby to define 
the conditions yourself.

def validate_on_create
  if parent_id.blank?
    errors.add(:parent_id, "cannot be blank.")
  end
  if other_condition == true
    errors.add_to_base("You can test as many conditions as you want in 
this method.")
  end
end

That''s how the custom validation functions work--you test the
conditions
and add to "errors" to flag a condition as invalid.

Alternatively, the way described above doesn''t actually keep you from 
supplying multiple conditions on create:

  validates_presence_of :parent_id, :name, :price, :message => "cannot 
be blank.", :on => :create
  validates_numericality_of :price, :on => :create
  validates_acceptance_of :terms_of_service, :on => :create

...and so on.

Check the Agile Web Development With Rails book for more examples, it''s
an invaluable resource.  The Rails API documentation will have the 
specifics on how to use "errors.add" and
"errors.add_to_base".

Hope this helps,

Jeff Coleman

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Posted via http://www.ruby-forum.com/.

thanks Jeff, now I see how it works.

Isabelle

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