Custom node types or additional metadata?

[JeffersonBledsoe]

The current node types cover alot of cases, but currently seem to be text/ file focused. How would you use JSON Canvas to build something like an audio editor such as PureData or Max/ MSP?

[nichtich]

Thanks for references, I did not know about these visual audio editors before. This looks similar to visual programming languages such as Scratch and Yahoo Pipes. I thinks it makes sense to broaden this issue to these kinds of tools where nodes on a canvas are connected via edges as well but both nodes and edges can have specific properties.

Another related model is labeled property graphs where each node and edge can have types (aka labels) and properties (arbitrary key-values).

The easiest way to support additional properties would be to introduce a properties field with a JSON object. Open questions are whether fields such as x ,and y have special meaning in properties and which kind of values should be allowed (single scalars, uniform arrays, any JSON structure).

[JeffersonBledsoe]

I thinks it makes sense to broaden this issue

Couldn't agree more! Personally, having a fairly fixed definition of positioning and grouping of nodes in a canvas (such as with the x and y fields) is the biggest strength to the spec and so they should continue to be treated as special cases. In my head, the custom properties field is an escape hatch for developers to add whatever additional information they need, and so any fields inside it shouldn't be treated as special and the fields that do specific things defined by the specification should be surfaced outside of the properties field.

[voxpelli]

Would be great to add some extensibility to JSON Canvas where someone independently of the core spec could define a new type.

A common mechanism for that would be to use something like example.com/the/new/type or com.example.type.new.the as the format for people who want to completely independently add a new type and possibly have an official registry of types where third parties can register their types, but the latter makes little sense to define before any third party types exists

[jessmartin]

We provide this exact extensibility mechanism in OCIF, a new format for infinite canvas tools. I'd be curious to hear your feedback on it.

We were inspired by JSON Canvas's simplicity but wanted to create something extensible. We don't yet have an OCIF <> JSON Canvas converter, but we're working on it.