Ability to remove available subscription levels & update level labels

[therajumandapati]

1. Is it possible to remove subscription levels such as New Topics Email and All Emails using hooks? I unfortunately was not able to find an easy way to do that globally as these levels seem to be hardcoded in many places.
2. Is it possible to update the subscription level labels using hooks (ex: New Topics Email to New Topics)?

I see you guys are working on a v4, not sure if either of these are planned in that release. Looking forward to hearing from you.

[therajumandapati]

Hi, I added this PR to help identify the options available on the Group Email Options tab. Please let me know if you that will work.

[boonebgorges]

Thank you for the PR - I have merged it.

I guess your strategy here is to hide these items with CSS. That seems OK to me, and I definitely have no problem adding the selectors to the markup.

That said, a more general solution would be to allow the subscription levels to be filterable. The subscription logic throughout the plugin is really difficult to abstract, and I think it would be very difficult to put a filter in place that allows plugins to add subscription levels. On the other hand, I can imagine a filter that allows you to remove subscription levels. This way, you'd be removing them globally, rather than using a CSS hack. If you think this is useful or promising in some way, perhaps you could work up a PR for it, or maybe I could look at it myself in the future.

[therajumandapati]

@boonebgorges Agreed that adding a filter to remove subscription levels is best compared to this CSS hack. Our goal is accomplished with #199. Thanks for the merge.