Port Mail Editor to Drupal 8

Thanks for jumping in, Miguel.kode!

Please be aware of Mail Editor's "special relationship" with Subscriptions. ME is useful in its own right, but it's also open for extensive customization by modules like Subscriptions, and this capability needs to be carried over into D8.

Have you been able to make any progress, Miguel.kode?

Fantastic, welcome!

I'm sorry, I'm on the road with little connectivity until the end of next week. I'll try to take a look ASAP before that, but I can't promise.

Thank you very much for working on it!

I found out that I've already branched 8.x-1.x from 7.x-1.x, but the latter got a few more commits, and I've committed #2735109: Some spaces disappear from long mail subjects (at least when using Mimemail). Now, I'm waiting for the testbot to complete. Then I'll tag 7.x-1.2, merge the missing commits to 8.x-1.x.

#18 doesn't apply to yesterday's 8.x-1.x—I assume you've diffed it against 7.x-1.x—but I'll just copy over the zip file and adjust the change log. There's nothing you need to do.

The testbot hasn't budged yet, I'll continue tomorrow.

Do you by any chance know whether the bug mentioned in #2735109: Some spaces disappear from long mail subjects (at least when using Mimemail) is also in your D8 port?

Thank you, that's a good start.

Here are some changes that I've made, and some comments:

1. +++ b/CHANGELOG.txt
   @@ -1,91 +1,3 @@
   -CHANGELOG.txt for Mail Editor for Drupal 7
   

   I prefer to keep the change log across major versions.

2. +++ b/mail_edit.module
   @@ -1,226 +1,39 @@
   +    case 'mail_edit.list':
   

   This needs to be 'help.page.mail_edit'.

3. I've added a dummy test so that I can enable the testbot.

4. Interestingly, admin/config/people/accounts is not working correctly in multi-language mode. I've done some experimenting by adding German. Core always displays and saves the English text, even when I switch to German. Your implementation OTOH initially displays the German text, but after editing and saving, you'll display the unchanged German original in German and the edited German version in English. Also, the subjects and text bodies are not exactly in sync.
5. I think we will need to make the distinction between Add and Edit again (as well as provide a Purge action), because having to open each template to check whether they are all customized is a pain. Likewise, seeing all the languages on the same page, rather than having to switch the language, helps to keep things in order, and it would be what we can offer on top of Core for the user emails.
6. What does the character count buy us?
7. The admin/config/system/mail-edit/% page is missing a page title.

I'm still checking it in as a work-in-progress, so that we have a base to build on.

Do you have a contrib that uses Mail Editor?

Hmm, can I not make the snapshot release visible on the front page anymore?

Thank you for publishing the snapshot!

I had specifically avoided adding an extra data storage layer because I felt the system should focus on editing the original emails. That way if someone edits the message in the original location there won't be any difference in what they see.

Yes, that makes sense for the user templates, there seems to be storage for each active language, but somehow neither Core nor Mail Editor manage to get the right slot (or even the same slot) for every operation...

However, for third party modules (like Subscriptions), that rely completely on Mail Editor, we'll need storage. Right now, Mail Editor doesn't offer much more than Core does.

Why the character count? I don't think I want to keep that...

The idea for 3rd party modules was to leverage existing configuration objects and to just work out a (better?) API to handle them? Then we'd be defining an API for other modules to take advantage of.

Yes, exactly. Client modules just define mailkeys and default text, and Mail Editor does the rest. It provides conditions and loops for working with tokens, and the client module can provide additional tokens to be used in the templates.

The Subscriptions module added a second template field (for formatting comments to go with nodes) and a preview mode. Preview cannot be provided by Mail Editor alone, because the client module has to supply the data to go with the template, but Mail Editor could help.