Background Tasks, Real-Time Updates & Sync

Production Architecture Deep DiveModule 7The lesson guide, the walkthrough video, the knowledge check and the hands-on lab this sample was built from are on learnwisej.com — free, with an AI tutor in every lesson.

Open the course

A 600-row CSV of tickets (with four deliberately bad rows) is imported on a background task started with Application.StartTask, progress and a log panel are pushed to the browser with Application.Update(this, () => …) at a bounded rate, ⏹ Cancel stops the run cooperatively between two rows and lets you resume, and every field the two threads share is guarded by one lock. The screen never freezes — ↻ Refresh list works while the import runs.

Nothing here is deployed anywhere; it is a plain Wisej.NET 4 project that runs on your machine.

The source of this sample

iceteagroup/LearnWisej-SamplesProduction Architecture Deep Dive/Module 7

Browse this folder on GitHub

Or clone it: git clone https://github.com/iceteagroup/LearnWisej-Samples.git — then open TicketOps.slnx in Visual Studio and press F5.

Run it

cd "LearnWisej-Samples/Production Architecture Deep Dive\Module 7\TicketOps"
dotnet run -f net10.0 --urls http://localhost:5107

Then open http://localhost:5107. (Visual Studio: open TicketOps.slnx, press F5 — the port is in Properties/launchSettings.json.)

Requirements: .NET 10 SDK, the Wisej-4 4.1.0 NuGet package.

To see the polling fallback, set "enableWebSocket": false in Default.json and restart: the pushes arrive about a second late, carried by Application.StartPolling(1000) / EndPolling().

What to try in the Ticket Import window

Action	Path	What you should see
▶ Start import	success + progress	the bar and n of 600 rows · imported · skipped advance; the import log gets Row 60 imported — 10% lines and four ⚠ Row … skipped — … lines (58 title, 214 due date, 287 assignee, 412 duplicate id). Ends with ✔ Import complete — 596 imported · 4 skipped. and 602 tickets in the repository
↻ Refresh list (during the run)	UI stays responsive	the count grows, the import log gets ✔ List refreshed — 237 tickets; the bar never stops
⏹ Cancel (during the run)	cancellation	amber banner Import cancelled. The rows already imported were kept; resume to continue.; Start now reads ▶ Resume import (row 349); click it to finish the file

If the data store fails mid-import, the run stops cleanly before the failing row, the details go to the log, the user sees The import stopped because the data store is unavailable. Recover it, then resume. and Start offers ▶ Resume import (row n). A second start while a run is active is refused under the lock.

Where things live

TicketOps/
├─ Views/ImportPage               the screen: launcher, progress marshaling, cancellation, BeginPush/EndPush
├─ Controls/StatusBanner          reusable "● state" + banner UserControl (display only)
├─ Services/                      IImportService / ImportService (the import logic, no Wisej types), ITicketService / TicketService
├─ Domain/                        Ticket, TicketImportRules (pure functions), ImportModels, OperationResult
├─ Data/
│  ├─ ITicketRepository.cs        persistence contract (InsertAsync is an atomic check-and-add)
│  ├─ InMemoryTicketRepository.cs lock-guarded fake store
│  └─ sample-tickets.csv          600 rows, ids 7001–7600, bad rows 58 / 214 / 287 / 412 (copied to the output folder)
├─ Infrastructure/                ILog / ActivityLog (server console), ImportFileLocator, AppComposition
├─ Resources/Strings.cs           safe user-facing messages (ImportCancelled, ImportInterrupted, …)
├─ docs/                          BackgroundTaskNotes.md · ImportRunbook.md
├─ Program.cs                     Wisej.NET session entry point → AppComposition
└─ Startup.cs                     Kestrel host (app.UseWisej())