Markup to emit for a node instead of the one its schema describes;
return null to leave the node alone.
This is how a document gets out carrying what the editor drew rather
than only what it holds, syntax highlighting is a decoration layer and a
diagram preview is an element the renderer appends, so neither is in the
model and neither would otherwise survive being serialized from it.
The string is emitted verbatim, not escaped. It is markup the host
produced, on the same footing as the diagram renderer's own output;
never hand this anything that arrived with a document.
Markup to emit for a node instead of the one its schema describes; return null to leave the node alone.
This is how a document gets out carrying what the editor drew rather than only what it holds, syntax highlighting is a decoration layer and a diagram preview is an element the renderer appends, so neither is in the model and neither would otherwise survive being serialized from it.
The string is emitted verbatim, not escaped. It is markup the host produced, on the same footing as the diagram renderer's own output; never hand this anything that arrived with a document.