Question: how do I do eager loading?

[rstacruz]

I'd like to be able to do this:

PublicActivity::Activity.all.includes(trackable: [:photos, :author])

But this isn't exactly possible like so, because trackable is polymorphic. I'll get errors like so:

Association named 'photos' was not found on Article; perhaps you misspelled it?
Association named 'author' was not found on Album; perhaps you misspelled it?

[pokonski]

This isn't the right place to ask about it, as it's totally unrelated to PublicActivity. Try Rails discussion groups or google for solutions, it's a common problem.

quick googling suggests:
http://blog.animascodelabs.com/2014/10/30/preloading-polymorphic-relationships-in-rails/
http://makandracards.com/makandra/28347-eager-loading-polymorphic-associations

[rutger1140]

I was looking for the same but couldn't quite figure it out (even after searching). Adding just .includes(:trackable) fixes the n+1 issue which I will use for now. @rstacruz did you find a proper fix for this?

[rstacruz]

.includes(:trackable) is correct, but I never found a way to eager load
second level associations like .includes(trackable: [:owner]).

On Monday, February 22, 2016, Rutger Laurman notifications@github.com
wrote:

I was looking for the same but couldn't quite figure it out (even after
searching). Adding just .includes(:trackable) fixes the n+1 issue which I
will use for now. @rstacruz https://github.com/rstacruz did you find a
proper fix for this?

—
Reply to this email directly or view it on GitHub
#251 (comment)
.

[jjf21]

Did anyone solve this problem ? include second level associations is not working for me neither ?
Thanks

[jjf21]

Just came back on this topic after while, if someone needs help, here is something that worked for me:

PublicActivity::Activity
   .includes(:trackable)
   .preload(trackable: [
       users: {avatar_attachment: :blob},
       ...
   ])

Good luck !