Validates_peresence_of

Rails
1

Is there an expert validater that can point me in the right direction?
I’ve looked for extended documentation on ‘validates_presence_of’ but i
can’t seem to find any.

I’m trying to make sure that i don’t enter a nil object in my database,
so i’ve added validate_presence_of to my Record Model.

i.e. -->
class Record < ActiveRecord::Base
validate_presence_of
end

I’m coming up with errors when trying this. Do i need to create a
function to handle the situation when i try leaving a field blank? Does
any one know of a good place to find detailed info on the validates
methods (Please don’t point me to the api, which has nothing worth while
there.

Thanks,
Yng

2

Yngwie wrote:

Is there an expert validater that can point me in the right direction?
I’ve looked for extended documentation on ‘validates_presence_of’ but i
can’t seem to find any.

I’m trying to make sure that i don’t enter a nil object in my database,
so i’ve added validate_presence_of to my Record Model.

i.e. -->
class Record < ActiveRecord::Base
validate_presence_of
end

I’m coming up with errors when trying this. Do i need to create a
function to handle the situation when i try leaving a field blank? Does
any one know of a good place to find detailed info on the validates
methods (Please don’t point me to the api, which has nothing worth while
there.

Thanks,
Yng

A little more info w/ details ==>
I have an edit .rhtml page which has the user enter ‘record’ data
fields. When I go to update these fields, i’m directed to the Update
controller which looks like

def update
@record.Record.find(params[‘id’])
if( @record.update_attributes(params[‘record’])
redirect_to :action => ‘view’
else
redirect_to :action => ‘edit’
end
end

So when i leave a field, that i’m validataing presence of, blank the
record doesn’t save and it goes directly to the else statement
(redirect_to :action => ‘edit’) How do I get the page to reload and
prompt the user to fill in the blank fields?

Thanks in advance,
Yng

3

Yngwie wrote:

Is there an expert validater that can point me in the right direction?
I’ve looked for extended documentation on ‘validates_presence_of’ but i
can’t seem to find any.

I’m trying to make sure that i don’t enter a nil object in my database,
so i’ve added validate_presence_of to my Record Model.

i.e. -->
class Record < ActiveRecord::Base
validate_presence_of
end

I’m coming up with errors when trying this. Do i need to create a
function to handle the situation when i try leaving a field blank? Does
any one know of a good place to find detailed info on the validates
methods (Please don’t point me to the api, which has nothing worth while
there.

Thanks,
Yng

A little more info ==>
I have an edit .rhtml page which has the user enter ‘record’ data
fields. When I go to update these fields, i’m directed to the Update
controller which looks like

def update
@record.Record.find(params[‘id’])
if( @record.update_attributes(params[‘record’])
redirect_to :action => ‘view’
else
redirect_to :action => ‘edit’
end
end

So when i leave a field, that i’m validataing presence of, blank the
record doesn’t save and it goes directly to the else statement
(redirect_to :action => ‘edit’) How do I get the page to reload and
prompt the user to fill in the blank fields?

Thanks in advance,
Yng

4

“Yngwie” [email protected] wrote in message
news:[email protected]…

Hi yng

I’m not sure what you mean by “nothing worthwhile” in the api docs. At
least
for validations, the documentation is very good:
http://api.rubyonrails.com/classes/ActiveRecord/Validations/ClassMethods.html

i.e. →
class Record < ActiveRecord::Base
validate_presence_of
end

it should be validates_presence_of, (you’re missing an s on ‘validate’)
and
you need to specify which attributes you are trying to validate.

Here’s an example from the api docs:

class Person < ActiveRecord::Base
validates_presence_of :first_name
end

hth
alan

5

you need to specify which attributes you are trying to validate.

Here’s an example from the api docs:

class Person < ActiveRecord::Base
validates_presence_of :first_name
end

hth
alan

Hey Alan,
thanks for the timely response,

I misspelled validates on this blog, but it’s was correctly spelled in
my record model. When i said the api wasn’t worthwhile, i meant that
the simple example they have doesn’t do me any good. I try to follow
the model, and ‘validates_presence_of’ just doesn’t allow me to save the
record. I need the user to be prompted to enter in a valid field. any
insight?

Thxs,
Yngwie

6

You may be asking how to display the validation errors to the user.
In that case, you want to use error_messages_for <http://
api.rubyonrails.com/classes/ActionView/Helpers/
ActiveRecordHelper.html#M000460> in the view.

The easiest way to learn this is to use “/script/generate scaffold
Test” and look at the code generated. It has nice examples of using
validations and displaying errors to users.

        - dan

–
Dan K. mailto:[email protected]
http://www.dankohn.com/ tel:+1-415-233-1000