Rails - Jan 2010 - Validates presence of special conditions not working

Here is the validation being used which is not working..

validates_presence_of :name => :controller_name, :if => :redirect?,
:message => "must have the same name as the controller."

The model has a string field for name.
The model has a boolean field for redirect.
The model has a string field for controller_name.

What I want to do is ensure that if the redirect box is checked for
true, that the name field matches the controller_name field precisely.

I''m not sure if validates_presence_of will do it.  I may have to create
a custom validation but am unsure how to proceed.

Much appreciation in advance...

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

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

On Jan 8, 2:59 pm, Alpha Blue
<li...-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:
> What I want to do is ensure that if the redirect box is checked for
> true, that the name field matches the controller_name field precisely.
>
> I''m not sure if validates_presence_of will do it.  I may have to
create
> a custom validation but am unsure how to proceed.
>
validates_presence_of doesn''t do that.

Custom validations aren''t scary. Adding a class method like

def validates_foo(*attr_names)
  options = attr_names.extract_options!
  validates_each(attr_names, options) do |record, attr_name, value|
    record.errors.add(attr_name, options[:message]) if ...
    end
  end
end

lets you do

validates_foo :attr1, :attr2

You get stuff like :if and :unless for free

Fred

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

Thanks for the explanation Fred.

I tried doing this but it''s not working properly:

def self.validates_is_exact(*attr_names)
  options = attr_names.extract_options!
  validates_each(*(attr_names << options)) do |record, attr_name, value|
    if record.send( options[:compare_field] ) == value
      record.errors.add(attr_name, options[:message])
    end
  end
  true
end

validates_is_exact  :name, :compare_field => :controller_name, :if => 
:redirect?, :message => "must have the same name as the
controller."

And ran a test in the console:

e = Page.new
e.name = "testname"
e.redirect = true
e.controller_name = "testname"
e.valid?
>>  e.valid?
=> false

Any idea what I might be doing wrong here?

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

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

I was reading the errors wrong.  It''s working properly.

Thanks Fred for the advice.
-- 
Posted via http://www.ruby-forum.com/.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

Here is the finished validation, corrected:

def self.validates_is_exact(*attr_names)
  options = attr_names.extract_options!
  validates_each(*(attr_names << options)) do |record, attr_name, value|
    if record.send( options[:compare_field] ) != value
      record.errors.add(attr_name, options[:message])
    end
  end
  true
end

validates_is_exact :name, :compare_field => :controller_name, :if => 
:redirect?, :message => "must have the same name as the
controller."

Basically, it compares the :name field value with the :compare_field 
field.value and if they are the same, validation is successful.  If they 
are different, it throws my custom message.

Thanks again Fred.  It was much easier than I anticipated.
-- 
Posted via http://www.ruby-forum.com/.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.