Rails - Oct 2005 - Reflective/Dynamic Access to AR Table Models

Hi all,

The short of my question is: Given a string in that represents the  
table name, how do I reflectively/dynamically get access to the AR  
Model class that represent it? (ie: from ''people'' get the
class
Person that extends ActiveRecord::Base)??

I''ve integrated the datavision report writer in with my rails app.  
I''m trying to use rails to gather the parameters needed to run the  
report and in the case of associations I want to give the user a drop  
down to select the parameter value.

so I have "people.name" as the parameter in my report file..

The first part is the hard bit.. How do I say "What is the AR model  
that represents the table ''people''?" ??

If I had that, it would be simple to do the rest.. ModelClass.find 
(:all).collect { |item| [ item.send( field ), item.id ] }

Failing this I could switch to "Person.name" for the parameter.. but  
even then.. How do I grab the class based on the string
''Person''??
eval ''Person'' would work but doesn''t feel right :(

Thanks in advance!

table_name, field_name = ''people.name''.split(/\./)

ActiveRecord::Base.const_get(
	table_name.classify
).find(:all).collect{|item|
	[item.send(field_name), item.id]
}


On Fri, 2005-10-14 at 15:33 -0400, Luke Galea wrote:
> Hi all,
> 
> The short of my question is: Given a string in that represents the  
> table name, how do I reflectively/dynamically get access to the AR  
> Model class that represent it? (ie: from ''people'' get the
class
> Person that extends ActiveRecord::Base)??
> 
> I''ve integrated the datavision report writer in with my rails app.
> I''m trying to use rails to gather the parameters needed to run the
> report and in the case of associations I want to give the user a drop  
> down to select the parameter value.
> 
> so I have "people.name" as the parameter in my report file..
> 
> The first part is the hard bit.. How do I say "What is the AR model  
> that represents the table ''people''?" ??
> 
> If I had that, it would be simple to do the rest.. ModelClass.find 
> (:all).collect { |item| [ item.send( field ), item.id ] }
> 
> Failing this I could switch to "Person.name" for the parameter..
but
> even then.. How do I grab the class based on the string
''Person''??
> eval ''Person'' would work but doesn''t feel right
:(
> 
> Thanks in advance!
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