With version 5.0, WordPress introduced a new post editing experience called Gutenberg . Instead of a rich text writing flow, the new editor prioritizes blocks to design and create content.
Advanced Custom Fields (ACF), WordPress' most popular custom field solution, launched their own wrapper to create custom blocks using PHP with version 5.8. Here at Fabrikat , we were so blown away by the possibilities of this solution that we decided to build an internal framework that makes composing ACF blocks easier and quicker. The result is Blockstudio. (BS)
What has initially started as a pure ACF PHP solution, is now completely agnostic. This means that you can choose between using ACF or Metabox (MB) Blocks as your field framework and use PHP and Twig (using Timber ) for templating.
Under the hood
On top of that, creating a unified way to declare blocks can help with the transition to and between different block frameworks. BS templates are structured in a way, that allow you to use the same templates and syntax for either ACF or MB blocks.
Why PHP blocks
You might wonder at this stage, why bother with Advanced Custom Fields or Metabox for block creation when you could just use WordPress core? While we have been toying with React based blocks for a bit, constructing new elements with ACF or MB has one big advantage over the "WordPress way":
Since the single file component approach is so central to BS, using ACF or MB blocks is the best option out there right now. Of course, we will keep our ears open to new developments and extend BS to use new APIs where we see fit!