Rich text field must be able to handle images from both regular img links and from Magnolia assets. CKEditor does provide handling of regular img links and the goal of this concept is to describe how to implement references to assets app. Pattern used here follows the one used in links with external and Magnolia pages.
Add asset button to rich text field toolbar next to image button.
This button would launch choose asset dialog:
After choosing selected image will be embedded to rich text field content.
Otherwise the behaviour is analogous to linking. Double clicking and context menus will behave like normal CK workflow replacing CKEditor's image dialog with Magnolia asset dialog depending on context.
As a reference to CKEditor's image dialog looks like this:
Data storing should be compatible with M4.5. Will need to investigate how data is stored and if it's necessary not to do so.
New plugin has to be created to CKEditor to handle new button and content. Common functionality with linking needs to be shared.