Missing? has_and_belongs_to_many with a has_one relationship----the tool/helper

Rails
1

In a dual boot computer the hardware has_and_belongs_to_many OS’s,
each os has only 1 set of hardware–how ever this is not has_many,
belongs_to as the OS does not belong to the hardware, it serves only
as the conduit.

I see no way to express this in rails–its a reverse has_many,
belongs_to, and is really just a semantics difference—but putting
belongs to where it doesnt belong makes things ugly because you put
labels on things that dont make sense.

any help? did i just no find the awnser or does this really not exist?

2

I’m not sure to understand exactly what you mean, but i’m afraid there
isn’t other way to express what you described.
It sound logical to say that a given Os instance could be linked to
only one set of hardware. And of course a given set of hardware can
“see” many Os running (sometime in the mean time!!). So it looks like
a has_many-belongs_to association.

But you can imagine a Conduit object that can be used as a join table:

class Harware < ActiveRecord
:has_many :conduits
:has_many :os, througt => :conduits
end

class Os < ActiveRecord
:has_one :conduit
:has_one :hardware, :througt => :conduit
end

class Conduit < ActiveRecord
:belongs_to :conduit
:belongs_to :os
end

I’m not sure it works exactly like that, but hope it helps

Mathieu BODIN