Update Watch to also support dynamic results

Author: LucDeCaf

PowerSync/PowerSync.Common/CHANGELOG.md

@@ -1,5 +1,14 @@
 # PowerSync.Common Changelog
 
+## 0.0.8-alpha.1
+- Replaced the old JSON-based method of extracting type information from queries with using Dapper internally for queries, improving memory usage and execution time for querying.
+- Added non-generic overloads for `GetAll()`, `GetOptional()`, `Get()`, `Watch()` which return `dynamic`:
+
+```csharp
+dynamic asset = db.Get("SELECT id, description, make FROM assets");
+Console.WriteLine($"Asset ID: {asset.id}");
+```
+
 ## 0.0.7-alpha.1
 - Added fallback to check the application's root directory for the PowerSync extension - fixing compatibility with WPF/WAP, .NET Framework <= 4.8, and other platforms that flatten DLLs into the base folder.
 - Added `ExecuteBatch()` implementation.

PowerSync/PowerSync.Common/Client/PowerSyncDatabase.cs

@@ -672,6 +672,24 @@ public async Task<T> WriteTransaction<T>(Func<ITransaction, Task<T>> fn, DBLockO
     /// Source tables are automatically detected using <c>EXPLAIN QUERY PLAN</c>.
     /// </summary>
     public Task Watch<T>(string query, object?[]? parameters, WatchHandler<T> handler, SQLWatchOptions? options = null)
+        => WatchInternal(query, parameters, handler, options, GetAll<T>);
+
+    /// <summary>
+    /// Executes a read query every time the source tables are modified.
+    /// <para />
+    /// Use <see cref="SQLWatchOptions.ThrottleMs"/> to specify the minimum interval between queries.
+    /// Source tables are automatically detected using <c>EXPLAIN QUERY PLAN</c>.
+    /// </summary>
+    public Task Watch(string query, object?[]? parameters, WatchHandler<dynamic> handler, SQLWatchOptions? options = null)
+        => WatchInternal(query, parameters, handler, options, GetAll);
+
+    private Task WatchInternal<T>(
+        string query,
+        object?[]? parameters,
+        WatchHandler<T> handler,
+        SQLWatchOptions? options,
+        Func<string, object?[]?, Task<T[]>> getter
+    )
     {
         var tcs = new TaskCompletionSource<bool>();
         Task.Run(async () =>
@@ -688,7 +706,7 @@ public Task Watch<T>(string query, object?[]? parameters, WatchHandler<T> handle
                     {
                         try
                         {
-                            var result = await GetAll<T>(query, parameters);
+                            var result = await getter(query, parameters);
                             handler.OnResult(result);
                         }
                         catch (Exception ex)

PowerSync/PowerSync.Maui/CHANGELOG.md

@@ -1,5 +1,8 @@
 # PowerSync.Maui Changelog
 
+## 0.0.6-alpha.1
+- Upstream PowerSync.Common version bump (See Powersync.Common changelog 0.0.8-alpha.1 for more information)
+
 ## 0.0.5-alpha.1
 - Upstream PowerSync.Common version bump (See Powersync.Common changelog 0.0.7-alpha.1 for more information)
 
@@ -20,4 +23,4 @@
 
 ### Platform Runtime Support Added
 * MAUI iOS
-* MAUI Android
+* MAUI Android

Tests/PowerSync/PowerSync.Common.Tests/Client/PowerSyncDatabaseTests.cs

@@ -524,4 +524,48 @@ await db.Execute(
         Assert.Equal(description, dynamicAsset.description);
         Assert.Equal(make, dynamicAsset.make);
     }
+
+    [Fact(Timeout = 2000)]
+    public async Task DynamicWatchTest()
+    {
+        string id = Guid.NewGuid().ToString();
+        string description = "new description";
+        string make = "some make";
+
+        var watched = new TaskCompletionSource<bool>();
+        var cts = new CancellationTokenSource();
+
+        await db.Watch("select id, description, make from assets", null, new WatchHandler<dynamic>
+        {
+            OnResult = (assets) =>
+            {
+                // Only care about results after Execute is called
+                if (assets.Length == 0) return;
+
+                Assert.Single(assets);
+                dynamic dynamicAsset = assets[0];
+                Assert.Equal(id, dynamicAsset.id);
+                Assert.Equal(description, dynamicAsset.description);
+                Assert.Equal(make, dynamicAsset.make);
+
+                watched.SetResult(true);
+                cts.Cancel();
+            },
+            OnError = (ex) => throw ex,
+        },
+        new SQLWatchOptions
+        {
+            Signal = cts.Token
+        });
+
+        await db.WriteTransaction(async tx =>
+        {
+            await tx.Execute(
+                "insert into assets (id, description, make) values (?, ?, ?)",
+                [id, description, make]
+            );
+        });
+
+        await watched.Task;
+    }
 }