Retrieving past values of a file variable from history

Hello everyone

I am checking how to handle properly process variables, specially how to provide audit capabilities to users to check what happened within a process.

The REST API allows to get update events with “/engine-rest/history/detail”

I can even retrieve what updates events affected a single variable with /engine-rest/history/detail?variableInstanceId=ca198047-f25a-11ec-9c7d-0242ac110003"

If one wants to extract the past values of a single variable in order to be presented to the human operators, that’s difficult.

When the variable is a primitive type (e.g. Bool), the previous call retrieves all past values. However, when the variable is file type, it just returns the filename, not the file content.

Calls to data retrieval return only the last value of the variable of the file “engine-rest/history/variable-instance/ca198047-f25a-11ec-9c7d-0242ac110003/data”

That REST GET call would return whatever the last value whatever the variable type, anyway, but simple variable types can be handled with the history/detail trick. For files, I don’t know how to achieve the same effect.

So, how can I retrieve past values of a file variable type from history? According to the doc, such values are stored even if they are binary provided the history mode is set to full, which apparently is.

Any help will be appreciated