Render partial from ApplicationController

Question

I'm trying to implement an action which will be invoked when user submits a new comment via ajax. When the comment is saved single comment partial must return. But it seems that render doesn't work as expected from ApplicationController. It displays an error that the view is not found, but it is in place (100%). When I'm adding :partial parameter it works, but doesn't pass any variables (and I need them!). Here's the controller code:

class ApplicationController < ActionController::Base
 protect_from_forgery
 def comment
 comment = Comment.new({
 story_id: params[:story_id],
 content: params[:content]
 })
 if comment.save
 render 'shared/comments/comment', comment: comment
 else
 render nothing: true, status: 400
 end
 end
end

• Nícolas Iensen: I'm wondering why aren't you using a CommentsController?
• Dima Knivets: Since this action will be used by several other controllers, it make sense for me to define it in global controller. And I think it's overkill to use separate controller for one action.
• Nícolas Iensen: I have to disagree with you, since this action handles the resource Comment it should be placed in the CommentsController, even if you have a comment form in a non CommentsController view. Also, there is no problem to create a controller for just one action.
• Marcelo De Polli: I have to agree with @nicolasiensen. Your action looks like a good candidate for a create action inside a CommentsController, in keeping with REST practices.
• Dima Knivets: Okay, thanks, I'll think about that.

Answer 1

Try using this syntax:

render :partial => 'shared/comments/comment', :locals => { :comment => comment }

• Dima Knivets: Thanks! Yeah, this works, but I've read in documentation that in new versions of Rails, you can just pass your variables without locals array and it works for me in other places, but not here. Why?
• Mischa: @DimaKnivets, according to Rails Guides, you should use object: comment in that case, not comment: comment.
• Marcelo De Polli: Yes, in this case since the variable has the same name as the partial, you can use object: comment. But I don't see any mention of this being a preferred option in the docs.