Rails Polymorphic Association - Join elements with similar relationships -

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i have system displays training resources skills , (basically) groups of skills on site. user can express interest in either skill or skill grouping stored in polymorphic table interests.

i'd display training each skill or skill group interest on user home page, in view, want iterate through interests have training (not skills or skill groups have training).

both skill.rb , skill_group.rb models define training resources relationship.

_interests.html.erb

# iterate through interests <% @user.interests.each |interest| %>    <% interest_element = interest.interest_element %>   <% if interest_element.training_resources.size > 0 %>     # more rendering code here...   <% end %>  <% end %>

interest.rb

class interest < activerecord::base   belongs_to :user   belongs_to :interest_element, :polymorphic => true end

ideally, i'd iterate through limited set of interests this:

@user.interests.joins(:interest_element => :training_resources).each |interest|

but can not eagerly load polymorphic association :interest_element error

is there way can type of join?

try @user.interests.includes(:interest_elements) works in rails 4.


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