Empty CSV File With Header Row

[Schevus]

I have a need to write an “empty” CSV file that includes only the header row information in the case that there’s no data to populate the file. Does anyone know a good way to do this? Anything to do with the CSV formatter and the header row options doesn’t seem to be working out. It’s always writing a row of data with blanks for each element separated by the delimiter. Appreciate any thoughts, thanks.

[tstack]

Schevus:

I have a need to write an “empty” CSV file that includes only the header row information in the case that there’s no data to populate the file.

I don’t think it’s possible to configure the CSV Formatter to do this at the moment. You might need to do something like the following to detect when there is no data:

Performing an Action when there is no data Designing Pipelines

A common integration pattern is to do something when no data is received. For example, we might read a file, parse it, and find that no records meet some filter criteria. As a result, we might send an email, or insert a ticket into a ticket management system like ServiceNOW. However, in SnapLogic, this can be somewhat more difficult than it seems initially because of the streaming architecture. In fact, many snaps will not execute without input documents - rather hard to accomplish when there i…

So, on the ‘No Data’ branch, you can have a Mapper that defines the headers and a CSVFormatter that writes the document to the file. Not great, I wish I had a better answer.

[Schevus]

Thanks tstack. That’s what we ended up implementing. Agreed, it is not great, especially for a document with dozens of header columns.

[ronmwhite]

For others whom happen to search for this as I just did. The router approach is still required as far as I can tell for the “No Data” condition, but, an easier way to write a header only file is to parse your JSON and use a Constant with a File Writer. For example, the following will get a list of Keys from your JSON (headers) as an array, turn it into a string, then, remove the opening and closing brackets.

JSON.stringify(Object.keys($)).replace(“[”,“”).replace(“]”,“”)

You can drop that into a Constant Snap and write to file. Works well for this case.

[mtran21]

Can you share a screenshot of your pipeline that handle this? from the router.
I am in the same situation. I need to write an empty with header CSV file if there is no input data.
Thanks