nodeCategoryProperty function expects to have the signature -
(a: ObjectData, b?: string) => string, which, IMO, should be (a: ObjectData, b?: string) => string | void, as this function should not return anything if it is being used as a setter.
If the second argument is supplied, the function should modify the node data object so that it has that new category name.
https://gojs.net/latest/api/symbols/Model.html#nodeCategoryProperty
For the function I have defined -
const categoryPropertyFunction = (partData: ObjectData, category?: string): string =>
{
if (category) partData.type = category;
else return partData.type;
};
I am getting TypeScript error:
TS2366: Function lacks ending return statement and return type does not include 'undefined'.
Here is an example of storing the category name as a property of the "d" property on the data object:
const model = . . .;
model.nodeCategoryProperty = function (obj: go.ObjectData, str?: string): string {
if (arguments.length > 1) obj.d.category = str;
return obj.d.category;
};
Note the use of function instead of using an arrow function, so that one can check the number of arguments.
The same kind of implementation can be used for the other "...Property" functional properties of the Model classes.