The primary theme framework for Exponent CMS is Twitter Bootstrap, currently at version 3 (actually 3.3.7). The next Bootstrap release, version 4 should be available in the near future and is currently in the beta 2 stage. It would be good to integrate support for the Bootstrap 4 framework, but there are several obstacles:
- Bootstrap 4 requires SASS/SCSS stylesheet compilation, where previous versions were based on LESS...and there is only one PHP based SCSS compiler available which chokes on some of our needed stylesheets. However, we've developed a 'hack' to compile them on the fly.
- Bootstrap 4 also leans toward needing 'autoprefixer' support to add additional 'browser-specific' styles into the compiled stylesheets. There is currently no PHP based autoprefixer (except for some which require node.js be running on the server). This may not be an issue since most modern browsers are supposed to be moving away from vendor specific style properties.
- Bootstrap 4 is a much greater departure (change) from the previous version (3) than in the past (e.g., v2 to v3). While not insurmountable, it will require updating a lot of Exponent code to produce compatible output for auto-generated form controls and menus, etc...
Now having said that, preliminary support for Bootstrap 4 (beta 2) is already being integrated into Exponent, which in turn also requires a new theme. Though the initial integration at this point is limited to functional navbars/menus and chrome, it is usable (if you can get past some of the odd styling on the page). It is expected this initial integration will be included in the next release of Exponent.
Once Bootstrap 4 is released as final AND we have fully integrated it with a functional theme, it will be released...most likely as Exponent v3. The roadmap to Exponent v3 will also throw off the shackles created by a need to support obsolete browsers and ancient PHP versions, both of which should not be used if security is of any importance. You can expect to see the next release of Exponent (either v2.4.1patch7, v2.4.2, or v3.0.0) around the end of the year.
Exponent CMS Developer