In order to provide styles for the iframe, we need to pass those
styles/script through the editor settings. The post and site editors use
get_block_editor_settings for that.
We currently build editor settings ourselves so I used the same function
_wp_get_iframed_editor_assets which is used internally in the get_block_editor_settings.
We also grab the assets early in the initialization phase, because _wp_get_iframed_editor_assets
reads from global $wp_styles and $wp_scripts and fetching the scripts later may include unwanted scripts.
[MAILPOET-6079]
When we create a new email in the new editor we ensure there is
also an associated NewsletterEntity.
This commit improves this functionality by replacing custom code with
NewsletterSaveController, which ensures that the sender name and address are set.
[MAILPOET-5646]
I envision the StylesController as the source of information about
styles settings in both the editor and renderer.
We will add email styles settings and these will be accessed in PHP via this service.
[MAILPOET-5540]
This changes how the editor is initialized. The integration initialization class
doesn't get the engine class anymore, but integration is initialized via
mailpoet_email_editor_initialized action triggered from the engine.
This allows multiple integrations to hook into the engine.
[MAILPOET-5540]