Unable to create an empty list

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1

I’ve tried two methods, per Gummie’s suggestions and neither work.

In this workflow:
https://www.gumloop.com/pipeline?workbook_id=cf8Nai1HMG6F8NXcX5oLx3

I would like the failure path of the error shield to create an empty list to the filter node. Without an empty list, the filter node fails on the first run because the spreadsheet reader has no rows other than the header row.

Option 1
Gummie suggested that I create a Duplicate node, specify the list size to zero and enter any string into Input1. This does not work because Input1 accepts only an input from a prior node; there is no way to enter a string.

Option 2
Then Gummie suggested that I use a Create List node with zero entries. Same issue. There is no way to specify strings for the lists—they must be inputs from prior nodes.

Also, there appears to be a bug with the UI. When I attempt to Run, it says there is an issue with the Dup node, highlights it in red and zooms in on it. It does not, however, actually tell me what the error is. The run does not get far enough for there to be an error in the log. Thus, I’m guessing what is actually wrong.

Any suggestions?

Cheers,
André

2

Hey @AangelHD! If you’re reporting an issue with a flow or an error in a run, please include the run link and make sure it’s shareable so we can take a look.

  1. Find your run link on the history page. Format: https://www.gumloop.com/pipeline?run_id={{your_run_id}}&workbook_id={{workbook_id}}

  2. Make it shareable by clicking “Share” → ‘Anyone with the link can view’ in the top-left corner of the flow screen.
    GIF guide

  3. Provide details about the issue—more context helps us troubleshoot faster.

You can find your run history here: https://www.gumloop.com/history

3

Hey @AangelHD – You can create an empty string using the Find and Replace node—for example: this pipeline.

That said, I don’t think this will work well for your case—mainly because the Join Paths node doesn’t support list inputs. It can’t reliably pick a path when there are multiple items in a single input. In my example, I set the number of rows to 1 so the output type is Text. We could work around the list limitation using a subflow, but that feels like overkill here.

Can you share more context on what you’re trying to do? Specifically, why would the sheet have empty rows to begin with, and how would you ideally want to handle them?

Right now, the solution we’re working toward seems too complex to set up.

4

Hi, Wasay.

Thanks for the method to create an empty string. Unfortunately, it’s not intuitive but I’ll remember that it’s possible. Perhaps there should be a “String” node for when hard-coded strings (which could be empty) are needed?

Well, there are four issues I raised:

  1. The filter node should allow empty lists. If it did, this whole problem goes away. When starting a process, it’s very common to start with an empty file (save the column title row).
  2. Gummie gave me wrong direction with the Duplicate node. There is no way to provide a string despite it directing me to do that.
  3. Gummie gave me wrong direction with the Create List node. Again, there is no way to create an empty list.
  4. The UI does not tell me what the error is despite giving me a red box around the node.

The goal is to start with a blank sheet of product names and build it up, page-by-page. When the flow starts with the first page there will be no product names.

So:

  1. Where can I report bugs?
  2. The easiest way around this is to add a dummy product name in row 2 of that spreadsheet then delete it later. I will do that unless you can think of a way to make this flow work.

Cheers,
André

5

Hey Andre,

Really appreciate the feedback and all of this makes a lot of sense. I’ll divide them in separate tickets for us to handle, everything you listed down should be possible.

As for Gummie, we’ve been head down focusing on making it 10x more powerful so it doesn’t hallucinate in certain cases like this. You’ll see an improved version really soon.

The easiest way around this is to add a dummy product name in row 2 of that spreadsheet then delete it later.

Yes I think that would be the easiest option for now.