ProseMirror's document model is a tree structure where positions are
calculated by traversing nodes, accounting for structural elements
(opening/closing tags of nodes like paragraphs, lists, etc.). A position
in ProseMirror is not "character index N". Structual boundaries like
"start of paragraph" also get their own index. A document with two
paragraphs "ab" and "cd" has positions:
0 1 2 3 4 5 6 7 8
<p> a b </p><p> c d </p>
So when I serialize a ProseMirror document to plain text for external
processing:
01 234
"ab\ncd"
I need to save this mapping information so when the external system
says "there's something interesting at characters [3,4]", I can map that
back to ProseMirror positions to do something useful: highlighting,
applying marks, or making selections.
fix: measure site visits
Use port 15000 for the default development port.
If you ever cloned the repo on Mac, ran the demo, and saw the models list
would never load, or saw 403 errors in browser console. Check the Server
headers. Good chances are the request went to AirPlay service which is also
listening on port 5000.
