bcquality/community/knowledge/performance/job-queue-handlers-must-not-require-ui.md

1.5 KiB

bc-version domain keywords technologies countries application-area
all
performance
job-queue
background-session
guiallowed
confirm
runmodal
client-callback
al
w1
all

Job queue handlers must not require user interaction

Contributions welcome — open a PR to refine or extend this article.

Description

A job queue handler runs in a background session with no client UI. Calls that require a client callback, such as Confirm, Page.RunModal, Report.RunModal, upload, or download, can stop the job with a non-retriable callback error. Message is suppressed and logged by the server, so it cannot communicate a result to the user who scheduled the job.

Best Practice

Make a dedicated job queue entry point non-interactive. Validate parameters and data in AL, persist business-visible status when needed, and let failures propagate to the job queue log. If one procedure genuinely serves both foreground and background callers, isolate optional UI-only behavior behind GuiAllowed; do not use the guard to silently skip a decision that the operation requires.

See sample: job-queue-handlers-must-not-require-ui.good.al.

Anti Pattern

Calling Confirm, Page.Run, Page.RunModal, Report.Run, Report.RunModal, Hyperlink, File.Upload, or File.Download from a codeunit run by the job queue. Another signal is using Message as the only success or failure notification: no user is attached to receive it.

See sample: job-queue-handlers-must-not-require-ui.bad.al.