Add support for value substitution in string based queries

.editorconfig

@@ -12,7 +12,7 @@ indent_style = space
 tab_width = 4
 
 # New line preferences
-end_of_line = crlf
+end_of_line = lf
 insert_final_newline = false
 
 #### .NET Coding Conventions ####

CHANGELOG.md

@@ -24,6 +24,7 @@
   var obj = new MyObject();
   obj.Denominations.Add("quarter", 0.25d);
   ```
+* Added support for value substitution in string based queries. This enables expressions following [this syntax](https://github.com/realm/realm-js/blob/master/docs/tutorials/query-language.md): `realm.All<T>().Filter("field1 = $0 && field2 = $1", 123, "some-string-value")`. (Issue [#1822](https://github.com/realm/realm-dotnet/issues/1822))
 
 ### Compatibility
 * Realm Studio: 10.0.0 or later.

Realm/Realm/DatabaseTypes/RealmCollectionBase.cs

@@ -158,9 +158,9 @@ public T this[int index]
             }
         }
 
-        internal RealmResults<T> GetFilteredResults(string query)
+        internal RealmResults<T> GetFilteredResults(string query, RealmValue[] arguments)
         {
-            var handle = Handle.Value.GetFilteredResults(query);
+            var handle = Handle.Value.GetFilteredResults(query, arguments);
             return new RealmResults<T>(Realm, handle, Metadata);
         }
 

Realm/Realm/Extensions/CollectionExtensions.cs

@@ -197,6 +197,7 @@ public static IDisposable SubscribeForNotifications<T>(this IDictionary<string,
         /// A Queryable collection, obtained by calling <see cref="Realm.All{T}"/>.
         /// </param>
         /// <param name="predicate">The predicate that will be applied.</param>
+        /// <param name="arguments">Values used for substitution in the predicate. Note that all primitive types are accepted as they are implicitly converted to RealmValue.</param>
         /// <returns>A queryable observable collection of objects that match the predicate.</returns>
         /// <remarks>
         /// This method can be used in combination with LINQ filtering, but it is strongly recommended
@@ -210,16 +211,18 @@ public static IDisposable SubscribeForNotifications<T>(this IDictionary<string,
         /// var results1 = realm.All&lt;Foo&gt;("Bar.IntValue > 0");
         /// var results2 = realm.All&lt;Foo&gt;("Bar.IntValue > 0 SORT(Bar.IntValue ASC Bar.StringValue DESC)");
         /// var results3 = realm.All&lt;Foo&gt;("Bar.IntValue > 0 SORT(Bar.IntValue ASC Bar.StringValue DESC) DISTINCT(Bar.IntValue)");
+        /// var results4 = realm.All&lt;Foo&gt;("Bar.IntValue > $0 || (Bar.String == $1 &amp;&amp; Bar.Bool == $2)" 5, "small", true");
         /// </code>
         /// </example>
         /// <seealso href="https://github.com/realm/realm-js/blob/master/docs/tutorials/query-language.md">
         /// Examples of the NSPredicate syntax
         /// </seealso>
         /// <seealso href="https://academy.realm.io/posts/nspredicate-cheatsheet/">NSPredicate Cheatsheet</seealso>
-        public static IQueryable<T> Filter<T>(this IQueryable<T> query, string predicate)
+        public static IQueryable<T> Filter<T>(this IQueryable<T> query, string predicate, params RealmValue[] arguments)
         {
+            Argument.NotNull(arguments, nameof(arguments));
             var realmResults = Argument.EnsureType<RealmResults<T>>(query, $"{nameof(query)} must be a query obtained by calling Realm.All.", nameof(query));
-            return realmResults.GetFilteredResults(predicate);
+            return realmResults.GetFilteredResults(predicate, arguments);
         }
 
         [EditorBrowsable(EditorBrowsableState.Never)]

Realm/Realm/Handles/CollectionHandleBase.cs

@@ -49,7 +49,7 @@ public ResultsHandle Snapshot()
             throw new NotSupportedException("Snapshotting this collection is not supported.");
         }
 
-        public abstract ResultsHandle GetFilteredResults(string query);
+        public abstract ResultsHandle GetFilteredResults(string query, RealmValue[] arguments);
 
         public abstract CollectionHandleBase Freeze(SharedRealmHandle frozenRealmHandle);
 

Realm/Realm/Handles/DictionaryHandle.cs

@@ -136,7 +136,7 @@ public override ThreadSafeReferenceHandle GetThreadSafeReference()
             return new ThreadSafeReferenceHandle(result);
         }
 
-        public override ResultsHandle GetFilteredResults(string query)
+        public override ResultsHandle GetFilteredResults(string query, RealmValue[] arguments)
         {
             throw new NotImplementedException("Dictionaries can't be filtered yet.");
         }

Realm/Realm/Handles/ListHandle.cs

@@ -213,7 +213,7 @@ public override ThreadSafeReferenceHandle GetThreadSafeReference()
             return new ThreadSafeReferenceHandle(result);
         }
 
-        public override ResultsHandle GetFilteredResults(string query)
+        public override ResultsHandle GetFilteredResults(string query, RealmValue[] arguments)
         {
             throw new NotImplementedException("Lists can't be filtered yet.");
         }

Realm/Realm/Handles/ResultsHandle.cs

@@ -62,7 +62,10 @@ private static class NativeMethods
             public static extern IntPtr snapshot(ResultsHandle results, out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "results_get_filtered_results", CallingConvention = CallingConvention.Cdecl)]
-            public static extern IntPtr get_filtered_results(ResultsHandle results, [MarshalAs(UnmanagedType.LPWStr)] string query_buf, IntPtr query_len, out NativeException ex);
+            public static extern IntPtr get_filtered_results(ResultsHandle results,
+                [MarshalAs(UnmanagedType.LPWStr)] string query_buf, IntPtr query_len,
+                [MarshalAs(UnmanagedType.LPArray), In] PrimitiveValue[] arguments, IntPtr args_count,
+                out NativeException ex);
 
             [DllImport(InteropConfig.DLL_NAME, EntryPoint = "results_find_object", CallingConvention = CallingConvention.Cdecl)]
             public static extern IntPtr find_object(ResultsHandle results, ObjectHandle objectHandle, out NativeException ex);
@@ -186,9 +189,21 @@ public override ThreadSafeReferenceHandle GetThreadSafeReference()
             return new ThreadSafeReferenceHandle(result);
         }
 
-        public override ResultsHandle GetFilteredResults(string query)
+        public override ResultsHandle GetFilteredResults(string query, RealmValue[] arguments)
         {
-            var ptr = NativeMethods.get_filtered_results(this, query, (IntPtr)query.Length, out var ex);
+            var primitiveValues = new PrimitiveValue[arguments.Length];
+            var handles = new RealmValue.HandlesToCleanup?[arguments.Length];
+            for (var i = 0; i < arguments.Length; i++)
+            {
+                (primitiveValues[i], handles[i]) = arguments[i].ToNative();
+            }
+
+            var ptr = NativeMethods.get_filtered_results(this, query, (IntPtr)query.Length, primitiveValues, (IntPtr)primitiveValues.Length, out var ex);
+            foreach (var handle in handles)
+            {
+                handle?.Dispose();
+            }
+
             ex.ThrowIfNecessary();
             return new ResultsHandle(this, ptr);
         }

Realm/Realm/Handles/SetHandle.cs

@@ -125,7 +125,7 @@ public override ThreadSafeReferenceHandle GetThreadSafeReference()
             return new ThreadSafeReferenceHandle(result);
         }
 
-        public override ResultsHandle GetFilteredResults(string query)
+        public override ResultsHandle GetFilteredResults(string query, RealmValue[] arguments)
         {
             throw new NotImplementedException("Sets can't be filtered yet.");
         }

Realm/Realm/Native/PrimitiveValue.cs

@@ -24,6 +24,7 @@
 
 namespace Realms.Native
 {
+    // This type is marshalled through C++ wrappers' realm_value_t
     [StructLayout(LayoutKind.Explicit)]
     [DebuggerDisplay("PrimitiveValue({Type})")]
     internal unsafe struct PrimitiveValue