Loop to poll a windows directory

[raelldata]

Has anyone managed to get a loop to continuously poll a windows directory for new files and trigger an analysis? I’m thinking that might be a way to implement near real-time analysis.

[ScottF]

Hi @raelldata -

Does this component do what you need?

Wait for File in folder (new filehandling) – gab1one

[mlauber71]

@raelldata I once built this thing that would check at certain intervals if a file has changed (store the most recent information) and if there is a change it would do something:

Start a Workflow, e. g. a database query, after a certain time

@USCHUKN1ME I tried to build a system you might be able to expand and use. The idea is to have a workflow that would iterate a number of times (v_number_of_intervals) with a set interval (of seconds) between (v_seconds_interval) them. The workflow looks for a trigger_file.csv if this file has changed from the last time the loop has run a component would be executed. If the file has not changed nothing would happen. Admittedly not the most elegant way but you could build a small automatic execu…

You could of course adapt the condition (something has to change within the file).

If you want to construct an infinite loop you could think about entering a breaking point you could set from outside knime like a Stopp.txt file. As long as it is not there the loop continues. This could be a more elegant solution than just forcefully stopping the knime program.