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Jeroen Houben

2006-Sep-07 14:52 UTC

how do you assign associated models?

Hi,

Just thinking out loud here:

When using a belongs_to (or any association type for that matter) how do 
you assign the associated object?

Example:

Employee belongs to a Company

do you do this:

e = Employee.new
e.company_id = 12

or

e = Employee.new
e.company = Company.find(12)

I find the latter more reliable when using validates_presence_of or when 
doing some custom validation that involves querying the Company. In fact 
I would like to make it the only way to assign association. I guess I 
could protect company_id from being set outside its class.

Jeroen

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Daniel Waite

2006-Sep-07 20:14 UTC

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Re: how do you assign associated models?

Jeroen Houben wrote:> When using a belongs_to (or any association type for that matter) how do 
> you assign the associated object?
> 
> Example:
> 
> Employee belongs to a Company
> 
> do you do this:
> 
> e = Employee.new
> e.company_id = 12
> 
> or
> 
> e = Employee.new
> e.company = Company.find(12)
Definitely the second. You''re correct in finding it more reliable. But 
also, it''s a practice belonging to a larger principle: code to an 
interface, not an implementation.

By accessing e.company_id you''re violating its encapsulation barrier. 
(In other words, you''re poking around in its internals, when you should
ask the object in question to do it for you.)

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Rails - Sep 2006 - how do you assign associated models?

how do you assign associated models?

Re: how do you assign associated models?