Patron notice templates and editor

Need the ability to define email, sms (text) and/or print templates depending on the institution/organization. For example, some organizations are required to send print notices for a fee/fine notice; whereas, some organizations have a no paper policy. For email, a subject, body (or multiple body parts) and signature are required. For sms, just a body of text is required. For print, they'll need to be able to include a patron name and address (for mailing) and body as well as signature.

It was suggested that contact information (and logo) being defined with location settings instead of in the notice itself. If it changes, then it is edited once, and it'll fix all notices.

Template requirements include:

• Layout
• Fonts, styles (perhaps somewhat limited though so accessibility regulations are considered)
• Tokens or individual fields, such as patron name, fee/fine description and amount
• Loop through multiple values, such as a list of all over items including multiple fields for each object (title and call number)
• Conditional, such as if patron type equals faculty, then... or if patron type equals student, then...

Also, the idea of consolidating notices came up. The use case that came up is over items from multiple library locations. For some institutions, it's simple, one notice with all items overdue with one statement about fee/fine policies and/or contact information. For some, it's more complicated, they might each have their own policies and/or generated fees, so it look something like this:

Library 1
Statement about fee/fine policy and/or contact information
List of items

Library 2
Statement about fee/fine policy and/or contact information
List of items

...

Also see UXPROD-675 for CRUD.

Not sure what templating language will be selected but some early ideas include Mustache. Mustache seems to be popular because of it's simplicity and it's ability to integrate with several languages as described by this comparison chart - (https://en.wikipedia.org/wiki/Comparison_of_web_template_engines). I'd suggest it's biggest drawback is that it won't handle the conditionals outlined above. It will do a simple if exists/not empty test, but that's it.

For what it's worth, a few developers at Cornell have researched the topic of rich-text editors combined with templating languages for an email notification system, and their solution eventually became a combination of Quill (https://quilljs.com/) because it stores the template as JSON (and got them out of some earlier trouble with tags and/or elements being stripped out) and Liquid Droplets (https://github.com/Shopify/liquid/wiki/Introduction-to-Drops) for field tokens and/or code snippets. Or at least I think I'm explaining that correctly! Here's a ticket that goes into some details about their research - https://github.com/cul-it/studentsite/issues/862#issuecomment-349994330.