Best way to have default user settings in Ruby on Rails?

Question

I'm currently working on a RoR application where users are able to register and have a list of (lets say 20) image-formats. These image-formats have their own model. The admin of the website is able to add or remove formats. The users should be able to activate certain formats or deactivate.

I was thinking of just adding the 20 formats to the database for each user, but that wouldn't be flexible if the admin chooses to delete or add one. Their should be a more maintainable way?

Answer 1

Your explanation isn't very detailed. Especially I'm missing the "default" settings from the question.

First thing (easy one): The Admin can create an entry for each format he wants to allow on the website. So there should be exactly one such entry in the table

Users can select from these formats several (up to a limit?) Why do they need to specially choose them? Can't they just use everything the admin allows? What would happen to uploaded images if the admin deletes a format?

Anyway, best would be a has_and_belongs_to_many relationship between the User and ImageFormat. Or another Model (UserImageFormat) that builds this bridge if any additional data is necessary.

For the case, that the Admin removes some formats, you can handle this in several ways. Either you add an "active" flag to the format record and then check for this each time you use the model or you actually just delete this record (in this case, make sure your associations are set with : dependent => :destroy so all the records that connect users to formats get destroyed too. (Write tests to ensure this)

Maybe you can find some gems or plugins that help with that. This article may give you some more help. Maybe some of the authentication plugins can add access control. But I think your need (user can in some way influence what he can use/access) could be too special, since most gems for this kind of work will more likely address an admin centered access control.