langiumLangiumDocuments.getOrCreateDocument return all properties except one properties

[zrwsmd]

my requirement ast root node is Ld like below second screenshot,when i call langiumLangiumDocuments.getOrCreateDocument(URI.parse(rootUri)) method,it return all properties(coils,ldnodes,locks) like below first screenshot except 'diagram',i want to know why(note:currently ,the corresponding file is an empty file)

[planger]

I think, this is because the document is empty. If the document is empty, I assume, the array properties in value are initialized with empty arrays [], but the object properties, such as diagram remain undefined until an actual value is set.

[zrwsmd]

i guess so,but how could it not be undefined?my requirement is when i drag a node(e.g:workflow tasknode)and save it ,corresponding file have text content,but when i create a node like below screenshot,at moment this.state.diagramRoot is still undefined,how could i assign it

[planger]

I'm afraid, this is hard for me to debug without stepping through the actual code.