Question

In the show action, there is logic that requires me to define:

@object.nested_object.new (or @object.nested_object.build or @object.nested_object.create)

However, when it’s time to show a list of the nested_objects using something like:

@object.nested_objects.each do |nested_objects|
  #display
end

There is an extra line item for the temporary nested object created with @object.nested_object.new.

Is there a way to forcefully remove that temporary object before I display the list of the actual nested_objects?

Or is there another way of accomplishing the following:

-creating a temporary nested_object for logic tests
-showing a list of nested_objects

I’ve tried stuff like:

temp_nested_object = @object.nested_object.new
temp_nested_object.delete

but wasn’t successful.

Thanks for your time!

UPDATE:
I’m trying to accomplish this:

<% if can? :create, @project.tasks.build %>

From here:
https://github.com/ryanb/cancan/wiki/Nested-Resources
I’ve tried to find other ways of accomplishing this:
https://github.com/ryanb/cancan/issues/608
but seems like I need to workaround it in the view.

Answer 1

First you should not create a temporary object.

if you follow the previous advice, simply do:

@object.nested_objects.select(&:persisted?).each do |nested_objects|
  #display
end

This will filter objects from your db (no need to delete a temporary object, it will disappear at the end of the request).