XafFilter

Custom column-filter UI for DevExpress XAF (Blazor Server) — five drop-in filter menus that replace the default DevExpress filter dropdown on a per-column-type basis, plus a fully tested demo app to prove they work.

The eventual deliverable is a reusable filter / query-builder library that drops into any XAF application; this repo is the proving ground.

Stack	.NET 10, DevExpress XAF 25.2.5 (Blazor Server), EF Core 10, SQL Server LocalDB
Tests	55 xUnit (criteria builders + demo seeder, sub-second) + 9 Playwright (Blazor + filter UI, ~80s)
Build configurations	Debug, Release, EasyTest (auto-creates a separate XafFilterEasyTest DB — used by the Playwright fixture)

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What's in the box

Five custom column-filter menus, automatically wired by column member type:

Filter	Targets	UI
DateRangeFilterMenu	DateTime, DateOnly	Two DxDateEdit (From / To)
NumericRangeFilterMenu	All numeric types (int, decimal, double, ...)	Two DxSpinEdit with N0 / N2 format
WildcardStringFilterMenu	string	Single DxTextBox accepting _ and %
EnumMultiSelectFilterMenu	enum types	DxListBox with one checkbox per enum value
BoolTriStateFilterMenu	bool	DxRadioGroup with All / Yes / No

Plus a [DisableCustomFilter] opt-out attribute for fields where the type-based heuristic picks the wrong filter (ID columns, legacy import keys, etc.).

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Screenshots

A guided tour through the demo app's Ticket ListView.

Seeded support-ticket list

Ticket is the demo BO; Customer and Agent are referenced from it. The seeder uses Bogus with a deterministic Randomizer.Seed = new Random(42), so each row count produces the same data every run.

Generate Demo Data (popup parameters object)

The Generate Demo Data toolbar action is a PopupWindowShowAction on the Ticket ListView. It collects a row count + date range + clear-first flag via a [DomainComponent] non-persistent BO, then runs the seeder in a fresh IObjectSpace and refreshes the view.

DateRange filter — Created At column

Click any column's funnel icon to open the filter menu. For DateTime / DateOnly columns the menu becomes a From/To date-range picker.

NumericRange filter — Priority column

Numeric columns get a From/To DxSpinEdit pair. Integer columns use N0 format, floating-point types use N2.

WildcardString filter — Subject column

String columns get a single text input that accepts SQL LIKE wildcards (_ for one char, % for many).

Enum multi-select — Status column

Enum columns render a DxListBox with a checkbox per value. Empty or all-selected = no filter.

Bool tri-state — Is Resolved column

bool columns get a three-way radio: All clears the filter; Yes and No filter to true / false.

Opt-out — Legacy Import Id column

Ticket.LegacyImportId is decorated with [DisableCustomFilter], so the default DevExpress filter menu (Select All + checkbox list) appears instead of the custom NumericRangeFilterMenu.

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How it works — the 5-step contract

Every custom filter follows the same lifecycle:

1. Controller.OnActivated subscribes to View.ControlsCreated.
2. Controller.View_ControlsCreated iterates editor.GridDataColumnModels on the DxGridListEditor, skips columns whose MemberType doesn't match this filter or whose property is marked [DisableCustomFilter], then sets FilterMenuButtonDisplayMode = Always and assigns a FilterMenuTemplate that renders the Razor component.
3. Razor.OnParametersSet calls a CriteriaBuilders.ReadXxx helper to recover the current inputs from FilterContext.FilterCriteria.
4. Razor.OnInputChanged calls CriteriaBuilders.BuildXxx and writes the result back to FilterContext.FilterCriteria. The grid re-filters on every input change — the popup's Apply button stays disabled because there are no pending criteria; the popup closes via Cancel or click-outside.
5. Controller.OnDeactivated unsubscribes ControlsCreated.

All criteria construction lives in XafFilter.Module/Filters/CriteriaBuilders.cs — pure helpers, no Blazor dependency, fully unit-testable.

The Razor components and their controllers are in XafFilter.Blazor.Server/Filters/ — paired by name (DateRangeFilterMenu.razor + DateRangeFilterMenuController.cs).

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Repository layout

XafFilter/
├── XafFilter.slnx                          ← solution file (new XML format)
├── XafFilter/
│   ├── XafFilter.Module/                   ← business objects, criteria builders
│   │   ├── BusinessObjects/Demo/           ← Customer, Agent, Ticket, GenerateDemoDataParameters
│   │   ├── Controllers/                    ← GenerateDemoDataController (platform-agnostic)
│   │   ├── DemoData/DemoDataSeeder.cs      ← Bogus-powered deterministic seeder
│   │   ├── Filters/
│   │   │   ├── CriteriaBuilders.cs         ← Build/Read pair per filter type
│   │   │   └── DisableCustomFilterAttribute.cs
│   │   └── Module.cs, XafFilterDbContext.cs
│   ├── XafFilter.Blazor.Server/            ← host
│   │   ├── Filters/
│   │   │   ├── Components/*.razor          ← five filter Razor components
│   │   │   └── Controllers/*.cs            ← five Blazor-side controllers
│   │   ├── Startup.cs, Program.cs, BlazorApplication.cs
│   │   └── appsettings.json                ← LocalDB connection + EasyTest connection
│   ├── XafFilter.Module.Tests/             ← xUnit — criteria builders, seeder
│   └── XafFilter.Blazor.Server.Tests/      ← Playwright — smoke + filter UI + theme
└── docs/
    ├── superpowers/plans/                  ← implementation plan that drove this work
    └── screenshots/                        ← README screenshots

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Running locally

Prerequisites:

• .NET 10 SDK
• SQL Server LocalDB (the Visual Studio installer's "Data storage and processing" workload, or stand-alone LocalDB installer)
• A trusted ASP.NET Core dev certificate: dotnet dev-certs https --trust

Start the host:

dotnet run --project XafFilter/XafFilter.Blazor.Server

The first run creates the XafFilter LocalDB database via Updater.cs when launched under a debugger (Visual Studio F5). From the CLI without a debugger, use the EasyTest configuration — it always runs the updater and points at the separate XafFilterEasyTest catalog:

dotnet run --project XafFilter/XafFilter.Blazor.Server -c EasyTest

Then open https://localhost:5001 and log in as Admin (blank password). Navigate to Ticket via direct URL (https://localhost:5001/Ticket_ListView) and click Generate Demo Data to seed.

Demo BO nav items are intentionally not in the side menu — the project's focus is the filter UI, not the demo CRUD. URL-route directly to /Ticket_ListView.

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Adding a new business object

Two things must happen or the type silently fails to appear in the XAF model:

1. Add a DbSet<T> to XafFilter.Module/BusinessObjects/XafFilterDbContext.cs.
2. Add AdditionalExportedTypes.Add(typeof(T)); to the XafFilterModule constructor in Module.cs.

And for navigation collections, always use ObservableCollection<T>, not List<T> — XAF's ChangingAndChangedNotificationsWithOriginalValues change-tracking strategy requires INotifyCollectionChanged. List<T> compiles and even unit-tests fine (the in-memory test DbContext uses a different strategy) but throws at CreateObject<T>() runtime in the real app. This bit Customer.Tickets and Agent.AssignedTickets once — see commit c987aea.

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Tests

# Unit tests — criteria Build/Read round-trips + DemoDataSeeder. ~1s.
dotnet test XafFilter/XafFilter.Module.Tests

# Playwright tests — login + filter UI rendering + light-theme. ~80s.
# First run downloads Chromium to ~/.cache/ms-playwright/.
dotnet test XafFilter/XafFilter.Blazor.Server.Tests

# Everything.
dotnet test XafFilter.slnx

How the Playwright fixture works

AppFixture spawns dotnet run -c EasyTest --no-launch-profile --urls=http://localhost:5000 from the test process, with ASPNETCORE_ENVIRONMENT=Development forced. The fixture then polls GET /LoginPage until it returns 200, opens Chromium headless, and exposes a NewLoggedInContextAsync() helper for individual tests.

Reasons for the non-obvious choices:

• HTTP/5000, not HTTPS/5001 — the default Blazor Server SignalR connection over wss:// fails its handshake against the untrusted dev cert in headless Chromium, even with IgnoreHTTPSErrors = true on the browser context. The Blazor circuit never starts, the page stays on the XAF splash logo. HTTP avoids the entire problem.
• ASPNETCORE_ENVIRONMENT=Development explicit — without --launch-profile the host defaults to Production, which makes UseStaticWebAssets() skip the _content manifest, and blazor.server.js 404s.
• -c EasyTest — the DatabaseVersionMismatch handler in BlazorApplication.cs only auto-runs the Updater when the EASYTEST symbol is defined or a debugger is attached.

Refreshing README screenshots

The screenshots in docs/screenshots/ are generated by ReadmeScreenshots.cs. It's [Skip]'d by default — un-skip it, run the test once, then put the skip back.

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Claude Code skills shipped with this repo

This project was implemented with Claude Code and several project-local skills live under .claude/skills/:

• /run-xaf — starts/stops the Blazor host with a port-free check + HTTP health probe.
• /xaf-filter-notes — domain reference for filter / criteria-editor work in XAF, including the 5-step contract documented above and the [DisableCustomFilter] opt-out pattern.

User-global skills also used heavily:

• xaf-efcore-entities — the XAF EF Core authoring rules (virtual properties, ObservableCollection, decimal precision, [Aggregated] cascade, etc.).
• xaf-viewcontroller-patterns — controller lifecycle, BoolList Active / Enabled, PopupWindowShowAction patterns.

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License

MIT © 2026 Martin Brekhof