* Initial setup work with error
* Dropdown working with error fixed
* Removed repition
* Home page billboard dropdowns added
* Created common file for dropdown
* Complete display ad dropdown usage
* Minor indentation fix
* Minor UI updates
* Minor test update
* Dropdown for billboard optimisation
* Added anchor tags
* Display ad unified code
* Design changes
* Design changes
* Changes to display ad click tracking
* Style changes
* Design change to admin display ad
* Nit fix
* Nit fix
* Updated test
* Make user_id optional for DisplayAdEvent
* Track when DisplayAd is visible to user
* Tidy up a bit
* Deleting a user account should nullify related DisplayAdEvents
* Update tests with new association details
Prior to this commit, we had a couple of references to magic strings
regarding DisplayAdEvent objects. This commit seeks to consolidate that
behavior.
In a handful of cases we had javascript variables, but as these JS files
are `erb` templates, we can inject the constant as well. This reduces
repetition of knowledge.
* Favoring delete_all on user relationships
Prior to this commit, several of the user's "has_many" were marked as
`depenedent: :destroy`.
In the case of :destroy, ActiveRecord instantiates each object and then
runs destroy. Whereas in the case of :delete, ActiveRecord issues a SQL
command to delete the related files.
It is often "safer" to use :destroy, as it guarantees that you'll
instantiate the record and run it's callbacks. But sometimes you have
to go with the speed of SQL.
And while not directly related to #15424 it is representative of our
callback ecosystem creating some unexpected computational loads.
Related to #15442 and #15424
* Noting models that user no longer cascade destroys
