Rails - May 2008 - Work out what are the included associations?

I have a person model:

Person
  has_many :phone_numbers
  has_one :address
  has_many :email_addresses

When I do the query:
people = Person.find(52, :include => [:address], :limit => 10)

How can I work out which associations we''re included.

i.e. in this case:
which_relationships_were_included(people) #=> [''address'']

The reason I want to do this is so that I can automatically marshall
data in a specific format into javascript.
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Alex Moore wrote:
> I have a person model:
> 
> Person
>   has_many :phone_numbers
>   has_one :address
>   has_many :email_addresses
> 
> When I do the query:
> people = Person.find(52, :include => [:address], :limit => 10)
> 
> How can I work out which associations we''re included.
> 
> i.e. in this case:
> which_relationships_were_included(people) #=>
[''address'']
> 
> The reason I want to do this is so that I can automatically marshall
> data in a specific format into javascript.
I think the best way is to look at what happens when you load an 
association.

person = Person.find(:first)
person.instance_variables == ["@attributes"]
person.address
person.instance_variables == ["@address", "@attributes"]

person = Person.find(:first, :include => :address)
person.instance_variables == ["@address", "@attributes"]

I know that worked with Rails 1.1.6
let me know if it doesnt in Rails 2

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Matthew Rudy Jacobs wrote:
> I think the best way is to look at what happens when you load an 
> association.
> 
> person = Person.find(:first)
> person.instance_variables == ["@attributes"]
> person.address
> person.instance_variables == ["@address",
"@attributes"]
> 
> person = Person.find(:first, :include => :address)
> person.instance_variables == ["@address",
"@attributes"]
> 
> I know that worked with Rails 1.1.6
> let me know if it doesnt in Rails 
Matthew: Works perfectly in rails 2.0, thankyou for the solution!
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I spoke to soon ...

So I can get a list of all the defined associations using:

assoc = model_instance.class.reflections.values.map {|r| ''@'' +
r.name.to_s} & model_instance.instance_variables

assoc.map {|a| a[1..-1]}.map {|a| 
model_instance.class.reflections[a.to_sym].class_name}

But the issue is when i have
people = Person.find(:all, :include => [:address,:suburb], :limit => 10)
give_me_a_list_of_all_the_included_attributes_including_those_in_relationships(people)

I can''t simply inspect people[0] and look at those relationships, 
because if people[0] doesn''t have an address defined and people[1] does
the left join means that I won''t see the suburb defined.

I thought an easy solution would be to hack up ActiveRecord::Base.find 
so that if an :include is passed, it stores that in each and every 
instance of the model.  That way I can just inspect the hash and easily 
work out what was included.

The only other option I can think, is having my method 
give_me_a_list_of_all_the_included_attributes_including_those_in_relationships 
take another parameter which specifies the includes which in the long 
run is not as easy for the end user.
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i think you can do person.address.loaded?

On May 2, 5:08 pm, Matthew Rudy Jacobs <rails-mailing-l...@andreas-
s.net> wrote:
> Alex Moore wrote:
> > I have a person model:
>
> > Person
> >   has_many :phone_numbers
> >   has_one :address
> >   has_many :email_addresses
>
> > When I do the query:
> > people = Person.find(52, :include => [:address], :limit => 10)
>
> > How can I work out which associations we''re included.
>
> > i.e. in this case:
> > which_relationships_were_included(people) #=>
[''address'']
>
> > The reason I want to do this is so that I can automatically marshall
> > data in a specific format into javascript.
>
> I think the best way is to look at what happens when you load an
> association.
>
> person = Person.find(:first)
> person.instance_variables == ["@attributes"]
> person.address
> person.instance_variables == ["@address",
"@attributes"]
>
> person = Person.find(:first, :include => :address)
> person.instance_variables == ["@address",
"@attributes"]
>
> I know that worked with Rails 1.1.6
> let me know if it doesnt in Rails 2
>
> --
> Posted viahttp://www.ruby-forum.com/.
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colin wrote:
> i think you can do person.address.loaded?
> 
> On May 2, 5:08�pm, Matthew Rudy Jacobs <rails-mailing-l...@andreas-
good spot Colin!

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Matthew Rudy Jacobs wrote:
> colin wrote:
>> i think you can do person.address.loaded?
>> 
>> On May 2, 5:08�pm, Matthew Rudy Jacobs <rails-mailing-l...@andreas-
> 
> good spot Colin!
Cheers Guys!
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