Polymorphic Associations

rubyonrails-talk
1

I have Titles and People, and I want a single Image class that can apply to either. I'm reading the Rails API on Polymorphic Associations, and I'm getting confused by the example. Can anyone explain how to do this:

Title   has_many :images

Person   has_many :images

Image   belongs_to [either :image or :title]

Thanks very much in advance,

Walter

2

Image class belongs_to :image_interface, polymorphic => true

Other classes has_many :images, :as => :image_interface

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3

In my opinion, this API is borked. See my other message for usage but I reckon the :as should be replaced with :using or something else

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4

Thanks very much. Good point, too.

Walter

5

Yeah because what you're doing is programming / adhering to an interface. This wording is the source of a huge amount of confusion for many programmers.

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6

Quite often you'll see examples trying to bake the nature of "interface" into the interface name. Things such as "attachable" or "imageable" and the like, but what this is really trying to do is say "this model can adhere to the interface named attachable". Naming the interface something strangely related to the model that provides the interface such as "attachable" is IMHO trying to "name around" a problem which needs to be more clearly labelled or re-engineered.

In my opinion the idea of interface needs to be built into ruby and rails a bit better.

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