Is there a way to add expressions (variables from other node) inside functions ?
Sorry do not understand what exactly you mean by that. Simply access data from other nodes?
Just like how I can reference output variables from other nodes in a node input by clicking the cog icon and clicking
Add Expression is it possible to do that inside a function node, for instance can I refer an ourput param
url from the
RSS feed read node inside the code of my function node as follow ?
Yes you can. It would however be:
items.json.myVariable = $node["RSS Feed Reader"].parameter["url"]; return items;
You can also check out the documentation. There everything is described: