This feature adds the ability to customize the HTML part of all emails using a custom HTML template and optionally some CSS to style it. The CSS will be parsed and converted into inline styles because CSS is poorly supported by email clients. When writing the custom HTML and CSS, be aware of what email clients support. Keep customizations very simple.
Customizations can be added and edited in Admin > Customize > Email Style.
Since the summary email is already heavily styled, there is a setting to disable custom styles for summary emails called "apply custom styles to digest" found in Admin > Settings > Email.
As part of this work, RTL locales are now rendered correctly for all emails.
This feature introduces the concept of themes. Themes are an evolution
of site customizations.
Themes introduce two very big conceptual changes:
- A theme may include other "child themes", children can include grand
children and so on.
- A theme may specify a color scheme
The change does away with the idea of "enabled" color schemes.
It also adds a bunch of big niceties like
- You can source a theme from a git repo
- History for themes is much improved
- You can only have a single enabled theme. Themes can be selected by
users, if you opt for it.
On a technical level this change comes with a whole bunch of goodies
- All CSS is now compiled using a custom pipeline that uses libsass
see /lib/stylesheet
- There is a single pipeline for css compilation (in the past we used
one for customizations and another one for the rest of the app
- The stylesheet pipeline is now divorced of sprockets, there is no
reliance on sprockets for CSS bundling
- CSS is generated with source maps everywhere (including themes) this
makes debugging much easier
- Our "live reloader" is smarter and avoid a flash of unstyled content
we run a file watcher in "puma" in dev so you no longer need to run
rake autospec to watch for CSS changes
