custom-nodes/js/javascript_hooks

[giscus[bot]]

custom-nodes/js/javascript_hooks

https://docs.comfy.org/custom-nodes/js/javascript_hooks

[geroldmeisinger]

To get a value passed to the node after execution use the following:

mynode.py

    def execute(self, inp0):
        result = inp0.reverse()
        return { "ui": { "input": inp0 }, "result": result }

mynode.js

	async nodeCreated(node)
	{
		if (node.comfyClass === "MyNode")
		{
			node.onExecuted = function (ui)
			{
			    console.log(ui.input)
			}
		}
	}

note that if you use OUTPUT_IS_LIST = (True,) you might want to put the ui message into a unit list, otherwise it's interpreted as an array (i.e. an array of characters for strings).

mynode.py

	RETURN_NAMES   	= ("out0",)
	RETURN_TYPES   	= ("STRING",)
	OUTPUT_IS_LIST 	= (True,)

    def execute(self, inp0):
        result = [v.reverse() for v in inp0]
        return { "ui": { "input": [inp0] }, "result": ] }

[geroldmeisinger]

This article is about hooks in Javascript context. If you are here because you're looking for hooks in Python context, note the following:

• Custom nodes are meant to be called by Comfy's prompt execution when needed, not as separate standalone sub-processes in the background
• Comfy does provide messages, but these are also meant to be handled by the client/frontend. You can send custom message from within your nodes though.
• There is a websocket example under script_examples/websockets_api_example_ws_images.py which does listen to server events, but the script itself is an external standalone process, is not executed from Comfy.
• If instead you want to call Python code from Javascript look into Routes.
• If instead you want to call Javascript code from Python look here: https://github.com/chrisgoringe/Comfy-Custom-Node-How-To/wiki/Passing-control-to-javascript

As far as I see it, it is not possible to provide background services with custom nodes, using only the official interfaces. Of course you can always hack something up.