It would be fun to go the postscript route and have the nodes be specified by some bytecode on some VM that lays the objects out on the canvas while specifying their editable properties.
Then, conforming implementations could render any document just by following the instructions, while editors that actually understand them can provide their own high-level control.
The trick is keeping it editable, which postscript doesn’t do well.
Example: if the language is strong enough to, say, implement force-directed node layout, an editor that doesn’t understand it could still add nodes and they would move around according to the document author’s wishes whereas perhaps the original editor might have more powerful editing capabilities.
Then, conforming implementations could render any document just by following the instructions, while editors that actually understand them can provide their own high-level control.
The trick is keeping it editable, which postscript doesn’t do well.
Example: if the language is strong enough to, say, implement force-directed node layout, an editor that doesn’t understand it could still add nodes and they would move around according to the document author’s wishes whereas perhaps the original editor might have more powerful editing capabilities.