feat: Blazor WASM counter sample + fix BLite.Wasm TFM for project references by Copilot · Pull Request #64 · EntglDb/BLite

Copilot · 2026-04-17T08:25:12Z

Addresses Issue 5 from WASM_SUPPORT.md: adds an end-to-end Blazor WebAssembly sample demonstrating BLite persistence in the browser via a counter app.

Sample — `samples/BLite.BlazorWasm/`

Minimal Blazor WASM app with a counter that survives page reloads:

Services/CounterStore.cs — singleton that calls BLiteWasm.CreateAsync("blite-counter-demo"), auto-selects storage backend (OPFS → IndexedDB → in-memory), and upserts a single counter document on every mutation
Pages/Counter.razor — increment / decrement / reset UI; displays active backend, last-saved timestamp, and persistence notice
Pages/Home.razor — landing page with quick-start snippet
wwwroot/blite-indexeddb.mjs / blite-opfs.mjs — JS interop modules (copied from BLite.Wasm/wwwroot) required by [JSImport] at runtime

// CounterStore.cs (core pattern)
Backend = BLiteWasm.DetectBestBackend();
_engine = await BLiteWasm.CreateAsync("blite-counter-demo", Backend);

var doc = _engine.CreateDocument(["name", "value", "updated_at"],
    b => b.AddString("name", "main")
         .AddInt32("value", Value)
         .AddInt64("updated_at", now.ToUnixTimeMilliseconds()));

_documentId = await _engine.InsertAsync("counters", doc);   // first run
await _engine.UpdateAsync("counters", _documentId.Value, doc); // subsequent

dotnet run --project samples/BLite.BlazorWasm/BLite.BlazorWasm.csproj
# open https://localhost:5001/counter

BLite.Wasm TFM fix

net10.0-browser → net10.0 — Blazor WASM projects target net10.0 (not -browser), so the old TFM produced a NU1201 restore error on project references. A new BrowserPlatform.cs adds [assembly: SupportedOSPlatform("browser")] to preserve the browser-only constraint that the old TFM provided implicitly.

Docs

WASM_SUPPORT.md — Issue 5 marked [Done]; running instructions added.

Agent-Logs-Url: https://github.com/EntglDb/BLite/sessions/335a7711-1dce-4bd1-840f-6a52bdd7b267 Co-authored-by: mrdevrobot <12503462+mrdevrobot@users.noreply.github.com>

Copilot

Pull request overview

Adds a new end-to-end Blazor WebAssembly sample to demonstrate BLite persistence in-browser, and adjusts BLite.Wasm to use a project-reference-friendly TFM while preserving browser-only API annotation.

Changes:

Add samples/BLite.BlazorWasm/: a minimal Blazor WASM “persistent counter” app that uses BLiteWasm with OPFS → IndexedDB → in-memory fallback.
Change BLite.Wasm TFM from net10.0-browser to net10.0, adding an assembly-level [SupportedOSPlatform("browser")] to keep the browser-only constraint.
Update WASM_SUPPORT.md and include the new sample project in BLite.slnx.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/BLite.Wasm/BrowserPlatform.cs	Marks the assembly as browser-only via `SupportedOSPlatform("browser")`.
src/BLite.Wasm/BLite.Wasm.csproj	Switches TFM to `net10.0` to avoid project-reference restore issues.
samples/BLite.BlazorWasm/wwwroot/index.html	Adds the Blazor WASM host page for the sample.
samples/BLite.BlazorWasm/wwwroot/css/app.css	Adds sample styling (loading/error UI + layout).
samples/BLite.BlazorWasm/wwwroot/blite-opfs.mjs	Provides OPFS JS module required by `BLite.Wasm` `[JSImport]`.
samples/BLite.BlazorWasm/wwwroot/blite-indexeddb.mjs	Provides IndexedDB (+ WAL) JS module required by `BLite.Wasm` `[JSImport]`.
samples/BLite.BlazorWasm/_Imports.razor	Sets up common Razor imports for the sample.
samples/BLite.BlazorWasm/Services/CounterStore.cs	Implements the persisted counter service backed by BLite browser storage.
samples/BLite.BlazorWasm/Program.cs	Wires up the Blazor WASM app and registers `CounterStore`.
samples/BLite.BlazorWasm/Pages/NotFound.razor	Adds a not-found page for the router.
samples/BLite.BlazorWasm/Pages/Home.razor	Adds landing page describing the demo + quick-start snippet.
samples/BLite.BlazorWasm/Pages/Counter.razor	Adds the persistent counter UI and status display.
samples/BLite.BlazorWasm/Layout/NavMenu.razor.css	Adds nav menu styling.
samples/BLite.BlazorWasm/Layout/NavMenu.razor	Adds navigation links (Home/Counter).
samples/BLite.BlazorWasm/Layout/MainLayout.razor.css	Adds main layout styling.
samples/BLite.BlazorWasm/Layout/MainLayout.razor	Adds main layout structure and GitHub link.
samples/BLite.BlazorWasm/BrowserPlatform.cs	Marks the sample assembly as browser-only via `SupportedOSPlatform("browser")`.
samples/BLite.BlazorWasm/BLite.BlazorWasm.csproj	Introduces the sample project + references `BLite.Wasm` and ensures JS modules are present.
samples/BLite.BlazorWasm/App.razor	Adds the app router and default layout wiring.
WASM_SUPPORT.md	Marks Issue 5 as done and documents how to run the sample.
BLite.slnx	Adds the new sample project to the solution.

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Copilot · 2026-04-17T08:31:06Z

+    public async Task InitializeAsync()
+    {
+        if (IsInitialized)
+            return;
+
+        try
+        {
+            // Detect the backend before creating the engine so we can display it.
+            Backend = BLiteWasm.DetectBestBackend();
+            _engine = await BLiteWasm.CreateAsync("blite-counter-demo", Backend);
+
+            // Try to restore the previously saved counter value.
+            await foreach (var doc in _engine.FindAllAsync(CollectionName))
+            {
+                if (doc.TryGetString("name", out var name) && name == CounterName)
+                {
+                    doc.TryGetInt32("value", out var saved);
+                    Value = saved;
+
+                    if (doc.TryGetId(out var id))
+                        _documentId = id;
+
+                    if (doc.TryGetValue("updated_at", out var tsVal) && tsVal.IsInt64)
+                        LastSaved = DateTimeOffset.FromUnixTimeMilliseconds(tsVal.AsInt64);
+
+                    break;
+                }
+            }
+
+            IsInitialized = true;
+        }
+        catch (Exception ex)
+        {
+            Error = $"BLite initialisation failed: {ex.Message}";
+        }


InitializeAsync() sets Error on failure but never clears it on a subsequent successful initialization. Because IsInitialized stays false after a failure, retries are possible, but the UI will keep showing the old error unless Error is reset on success (or at the start of initialization).

Copilot · 2026-04-17T08:31:06Z

+            _engine = await BLiteWasm.CreateAsync("blite-counter-demo", Backend);
+
+            // Try to restore the previously saved counter value.
+            await foreach (var doc in _engine.FindAllAsync(CollectionName))


This async method dereferences the nullable field _engine after await points (e.g., await foreach), which will typically produce nullable warnings and makes the code harder to reason about. Consider using a local non-null engine variable (capture the result of CreateAsync into a local, then assign the field) and use that local for the rest of the method.

Suggested change

_engine = await BLiteWasm.CreateAsync("blite-counter-demo", Backend);

// Try to restore the previously saved counter value.

await foreach (var doc in _engine.FindAllAsync(CollectionName))

var engine = await BLiteWasm.CreateAsync("blite-counter-demo", Backend);

_engine = engine;

// Try to restore the previously saved counter value.

await foreach (var doc in engine.FindAllAsync(CollectionName))

Copilot · 2026-04-17T08:31:07Z

+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>BLite WASM Demo</title>
+    <base href="/" />
+    <link rel="preload" id="webassembly" />


<link rel="preload" id="webassembly" /> is missing the required attributes (at least href and as). As written it won't preload anything and may trigger HTML validation / browser console warnings; either remove it or specify the actual resource and as type you intend to preload.

Suggested change

<link rel="preload" id="webassembly" />

feat: add samples/BLite.BlazorWasm counter demo + fix BLite.Wasm TFM

742ab37

Agent-Logs-Url: https://github.com/EntglDb/BLite/sessions/335a7711-1dce-4bd1-840f-6a52bdd7b267 Co-authored-by: mrdevrobot <12503462+mrdevrobot@users.noreply.github.com>

Copilot AI assigned Copilot and mrdevrobot Apr 17, 2026

Copilot created this pull request from a session on behalf of mrdevrobot April 17, 2026 08:25 View session

mrdevrobot marked this pull request as ready for review April 17, 2026 08:25

Copilot AI review requested due to automatic review settings April 17, 2026 08:25

mrdevrobot merged commit 0c4c404 into main Apr 17, 2026

Copilot started reviewing on behalf of mrdevrobot April 17, 2026 08:26 View session

Copilot AI reviewed Apr 17, 2026

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dependabot Bot mentioned this pull request Apr 24, 2026

deps: Bump BLite from 4.3.1 to 4.4.1 MPCoreDeveloper/SharpCoreDB#217

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feat: Blazor WASM counter sample + fix BLite.Wasm TFM for project references#64

feat: Blazor WASM counter sample + fix BLite.Wasm TFM for project references#64
mrdevrobot merged 1 commit intomainfrom
copilot/add-sample-counter-wasm

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Copilot AI commented Apr 17, 2026

Sample — samples/BLite.BlazorWasm/

BLite.Wasm TFM fix

Docs

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Sample — `samples/BLite.BlazorWasm/`