Initially, I tried to place the definition to theme.json (It could set it in styles.block.core/heading or styles.elements.h1...) It was not possible to use theme.json because of the fluid typography feature which, when enabled for a site, causes font sizes to being converted to the fluid definition (clamp(x, y, z)) and which is not usable for an email due to very little client support. We need to make some changes in Gutenberg to be able to disable the feature. Currently, the code for generating font sizes in CSS generated from the theme.json looks directly at the global settings of the site. [MAILPOET-5740]
MailPoet Email Editor
This folder contains the code for the MailPoet Email Editor. We aim to extract the engine as an independent library, so it can be used in other projects. As we are still in an exploration phase we keep it together with the MailPoet codebase.
Development
Bot PHP and JS code are divided into engine
and integrations
subdirectories.
Anything MailPoet specific is in the integrations/MailPoet folder.
For the core stuff that goes to the engine folder, avoid using other MailPoet-specific services and modules. The code in the Engine folder should work only with WP code or other stuff from the engine.