Prepare Revisions
Validate document targets, access, labels, and comparison readiness before alignment or comparison begins.
Preconditions: The host application has two document targets and enough authorization to load both assets through the viewer workflow.
- 1Assign file roles. Treat the older source as background and the newer source as overlay unless the product UI uses different labels.
- 2Validate URL shape. Each target should be absolute, reachable by the viewer runtime, and free of expired or malformed tokens.
- 3Validate access. Confirm the file host allows the viewer origin to retrieve the asset, or route access through the approved backend path.
- 4Validate format support against the product capability list before dispatching a compare or align request.
- 5Validate source intent. Both files should represent the same sheet, page, model view, or physical area.
- 6Capture display labels so the user can clearly see which file is background and which file is overlay during recovery and retry.
- 7Record whether alignment is likely required based on page size, scale, orientation, margins, source system, or scan/export path.
Both document targets are accessible, supported, clearly labeled, and ready for either direct comparison or interactive alignment. The host application should not allow the next step until these checks pass.
Run these checks in the application layer before sending work to the viewer:
- Both URLs are present and use an allowed protocol for the current environment.
- Authentication tokens or signed URLs are valid for the expected session duration.
- The file types are allowed by the current Revision capability documentation.
- The selected pages or sheets represent the same intended drawing area.
- The UI clearly identifies background versus overlay before the operator starts.
- The application has a recovery path for inaccessible, expired, or unsupported files.
If preparation fails, keep the user on the setup step, show which file failed validation, preserve the other valid input, and offer a clear action: refresh authorization, replace the file, choose another sheet, or upload through the supported path.