Hello? Bueller? Anyone?
I am building a similar WDC that uses a login procedure prior to data import as well.
It sounds like the issue you're having may not be related to the login if you're able to get things working correctly in the Simulator. I had this experience as well but was able to troubleshoot through some of it.
I'd suggest checking for the following:
1) Ensure that you're passing any needed data correctly using tableau.connectionData
2) Ensure that your column names contain only letters, numbers, or underscores (this is a big issue)
3) Ensure that your data is in an array/JSON in data.appendRows() (not sure this is a big deal, but can't hurt to cover your bases).
I'd also strongly suggest trying the built-in desktop debugger (PC only). It helped me troubleshoot quite a bit.
Hope this helps,
Thanks for the response. I've used these tools, but to no avail. The issue continues to be that while the simulator does not do this, the Tableau desktop software reloads the WDC page after it gets the initial schema. Because it's doing this and dropping the URL parameters in the process, it's being intercepted by the source application and stagnating at the login page. Looks to be a bug with how Tableau reloads the page, taking only the base URL and not the entire thing.
I've worked around it by instead creating my own login page, which then uses REST API calls to the source application to login and proceed. This isn't nearly as graceful, and means I'm maintaining the same login page in two places, but at least it's functional.