I'm currently migrating from Seagull.BarTender.Print to the newer Seagull.Services.PrintScheduler API.

Previously, I was using a single shared Engine() instance to:

• Open the label format
• Retrieve document data sources via LabelFormatDocument.SubStrings
• Export thumbnails/images

This worked well, but the documentation mentions that Seagull.BarTender.Print is legacy/superseded, so I started testing the Print Scheduler API instead.

My current goal is:

1. Generate a thumbnail/preview image of the label
2. Retrieve the document data sources (for example ScreenData, named data sources, prompts, etc.)

I tried using QueryDocumentAction with the following request parameters:

action.RequestParameters.Add("DataEntryFields");
action.RequestParameters.Add("NamedDataSourceFields");
action.RequestParameters.Add("QueryPromptFields");
action.RequestParameters.Add("GlobalDataFields");

However, all of these return null.

My questions are:

• Is there a way to retrieve all document data sources (including ScreenData) using the Print Scheduler API?
• Are these request parameters only supported for specific document types/features?
• What is the recommended approach for efficiently generating thumbnails while also retrieving document metadata/data sources?
• Is continuing to use a shared Engine() + LabelFormatDocument still the recommended approach for document inspection scenarios?

Any guidance or best practices would be appreciated.