List drop items behaves differently in custom node


I am wanting to use the ‘List.DropItems’ node within a custom node but it is behaving different to how it would outside of the custom node. I am using ‘-1’ as the amount to remove the last item. Outside of the custom node it works fine. Inside the custom node, something is happening to the lacing and/or list structure because it removes the wrong elements. Any ideas as to why this would be happening?


A screenshot of your graph would be nice…

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Here you go

The custom node’s input definition is very important. Each node placed inside will be affected if you defined an input as accepting a singleton, a list, or a list of lists, instead of the default var:[]…[]

I haven’t actually defined any input type. Does this mean var: is automatically assigned and i need to change it to var since it is a list of lists?


It should. You can hover your mouse over the input port and check. Alternatively, you could right-click the node and select Help for a detailed view.

But if that’s the case, then I’m not sure why the drop item node acts any different. I suspect the issue might be in the “IF” node prior to it. It’s notorious for messing up the list structure when its inputs are of varying length and depth.

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This feels likely…

It’s not the IF node I’ve double checked. The dropping last item is happening after it. Its driving me nuts. I’ve never seen this happen before.

I can’t replicate this. Have you tried recreating the custom node?


Yes IF is dropping last, I had to apply IF to last item in both list and then add the recaptured items to end of the IF list that was dropping last item.