I’m trying to find a way to execute knime automatically as it sees that the input file has changed.
Is there any way to trigger that?
Because I’m conneting knime to power bi and I would like it to be refreshed automatically.
You could call your workflow from a second “controller” workflow, which consists of a loop containing a
Wait... Node, which said for a file to be updated, then a
call remote workflow or
call local workflow node too actually run your “real” workflow
Is there any example of this nodes?
There is a built-in scheduling functionality on KNIME Server, if you have regular scheduled updates of data. This have an easy-to-use and flexible user interface and there is a walk-through in this presentation (up until 9:23). It also allows you keep track of executted jobs for inspection in the case of unexpected results.
Related to you last question, the nodes to call other workflows are Call Workflow (Table Based) and Call Local Workflow (Row Based). The first sends the whole table an input to the other workflow, i.e. execution of the workflow happens once. The second calls the other workflow for each row in the input table, i.e. multiple workflow executions. There are examples linked on the hub, but you can look at this one or this one for the two nodes respectively. You’ll have to implement additionally the looping option with some waiting interval, as suggested by @s.roughley.
You can use the Wait… node with the option ‘Wait for file …’ and ‘Modification’ enabled.