Dynamic attributes!

rubyonrails-talk
1

I want to create a general model 'Product' that I will be able to store several attributes in it.

For example the attributes

:id :name :description

are pretty stantard. So each product will have this attributes.

However, I wanted to know if it is possible to create dynamic attributes. In the case of a cell phone device I might want to store the IMEI of the phone, this attribute is useless if the product is a laptop.

Is there any whey to create dynamic attributes ?

2

You may look into Single table inheritance to see if that'll suit your needs. Otherwise you could look into something like mongomapper and mongodb.

3

Matt W. wrote:

You may look into Single table inheritance to see if that'll suit your needs.

STI won't do the trick here. Multiple-table inheritance might.

Or you could have a separate Attribute model, or (ugly) put all the "extra" attributes into a serialized Hash.

But really, you should probably have several different tables, not the undifferentiated Product.

Otherwise you could look into something like mongomapper and mongodb.

Or CouchDB.

Best,

4

If you wanna search across this dynamic attributes, you might take a look at acts_as_solr_reloaded, it has support for dynamic attributes:

http://github.com/dcrec1/acts_as_solr_reloaded

you just need to run a migration:

script/generate dynamic_attributes_migration

and then define your model like this:

acts_as_solr :dynamic_attributes => true

This will anotate your model like:

has_many :dynamic_attributes

where DynamicAttribute is a class with name and value properties, like:

DynamicAttribute.new :name => 'imei', :value => '123456-12-123456-1'

Then you can search like this:

Product.search "imei:'123456-12-123456-1'"

More info here:

http://www.diegocarrion.com/2010/01/18/thinkingsphinx-exits-enters-actsassolrreloaded/

cheers