active_record has_many, :through and active _resource

[bitcoiners]

Hello,
I have many to many relationship between Venue and Catalog

class Venue < ActiveRecord::Base
  has_many :venue_catalogs
  has_many :catalogs, :through => :venue_catalogs
end

class VenueCatalog < ActiveRecord::Base
  belongs_to :venue
  belongs_to :catalog
end

class Catalog < HyperactiveResource
    self.columns = [ :id, :description]
end

when I call url /venues.xml I get
undefined method `quoted_table_name' for Catalog:Class

seems belongs_to HyperActiveResource is not recognizing catalog is not an ActiveRecord.

[taryneast]

Quick answer: HABTM relationships are not yet implemented. Same with the :through attribute.

Longer answer: Active Record makes the assumption that a HABTM object is another Active Record., and expects it to respond to stuff like "quoted table name" - it will, in fact, try to build a select statement using joins to get your catalogs...
which is obviously not what you intend here.

I've not yet implemented HABTM or :through and haven't yet looked at how they are implemented as they're somewhat more complex than the simple relationships.

For now, all I can suggest is not trying to use :through on an Active Resource. Instead fetch the set of catalogs out of your venue_catalogs using a hand-coded method. Possibly something as simple as:

def catalogs
  venue_catalogs.map &:catalog
end

though I clearly haven't tested this code so it may not work - use with common sense ;)

Cheers,
Taryn

[bitcoiners]

thanks for the tip. that worked. but i am puzzled by this line
venue_catalogs.map &:catalog
what does it do?

[bitcoiners]

is an equivalent of venue_catalog.map {|v| v.catalog }?

[taryneast]

Yep - it is just that.
It's a bit of ruby magic that makes a Proc out of the given symbol. Really neat if all you're doing in the map is just a single, known, named method.