Ability to specify association preloading when populating belongs_to association selection.

[MrJoy]

I use a custom display_name method for a model (TransformersToyline). It makes use of a certain association (TransformersVendor) in synthesizing the final value. When I'm editing an item that belongs_to TransformersToyline, the select list is populated using display_name, but the includes configuration from TransformersToylineResource is not used. Of course, it would be imprudent to use this in most cases, but having the ability to separately specify the association preloading behavior for the populating-a-dropdown list would be very useful in these cases to avoid N+1 situations.

[adrianthedev]

Is that something you can do with rails associations?

I mean, this is not valid code.

TransformersToyline.find(1).includes(:something).vendor

What you could do to avoid n+1 is to make that field a searchable field.

[MrJoy]

It seems like what's happening under the hood is that it's getting TransformersToyline.all, to populate the <select>, and while iterating it's calling display_name to get the label value, which then references the vendor association.

Thanks for the searchable tip. I was able to toss in a .includes and get rid of the N+1 that way. Although, initially I didn't read the part about needing self.search_query set on the target resource and was very confused by the lack of any results. An error message might be helpful for unobservant folks like myself.

[adrianthedev]

Got it! I surfaced that a bit better. Thanks!