add support calling methods on interfaces and deref interface properties

Author: darnocian

src/Sempare.Template.Evaluate.pas

@@ -1112,12 +1112,23 @@ function TEvaluationTemplateVisitor.Invoke(const AExpr: IMethodCallExpr; const A
   LObjType: TRttiType;
   LObject: TValue;
   LMethod: TRttiMethod;
+  LIntf: IInterface;
 begin
   LObjType := FContext.RttiContext.GetType(AObject.TypeInfo);
-  LMethod := LObjType.GetMethod(AExpr.Method);
   LObject := AObject;
-  if AObject.IsType<TValue> then
-    LObject := AObject.AsType<TValue>;
+  if LObject.Kind = tkInterface then
+  begin
+    LIntf := LObject.AsInterface;
+    LObject := TObject(LIntf);
+    LObjType := FContext.RttiContext.GetType(LObject.TypeInfo);
+  end
+  else
+  begin
+    if AObject.IsType<TValue> then
+      LObject := AObject.AsType<TValue>;
+  end;
+  LMethod := LObjType.GetMethod(AExpr.Method);
+
   exit(DoInvoke(AExpr, LMethod, LObject, AArgs, AHasResult));
 end;
 

src/Sempare.Template.Rtti.pas

@@ -915,6 +915,8 @@ function TryDeref(const APosition: IPosition; const AVar, ADeref: TValue; const
   var
     LFunctionPair: TPair<TDerefMatchInterfaceFunction, TDerefFunction>;
     LIntf: IInterface;
+    LProperty: TRttiProperty;
+    LType: TRttiType;
   begin
     LIntf := AObj.AsInterface;
     for LFunctionPair in GDerefInterfaceFunctions do
@@ -925,10 +927,14 @@ function TryDeref(const APosition: IPosition; const AVar, ADeref: TValue; const
           exit(true);
       end;
     end;
+    LType := AContext.RttiContext.GetType(AObj.TypeInfo);
+    LProperty := LType.GetProperty(ADeref.AsString);
+    if assigned(LProperty) then
+      AResult := LProperty.GetValue(AObj.AsType<pointer>);
     exit(ExitEmpty(AResult));
   end;
 
-  function FixTValue(var AValue: TValue; const AResult:boolean=true): boolean;
+  function FixTValue(var AValue: TValue; const AResult: boolean = true): boolean;
   begin
     if (AValue.Kind = tkRecord) and MatchValue(AValue.TypeInfo) then
     begin

tests/Sempare.Template.TestDeref.pas

@@ -54,6 +54,12 @@   TTestTemplateDeref = class
     procedure TestDerefError;
     [Test]
     procedure TestDerefNull;
+
+    [Test]
+    procedure TestIntfProperty;
+
+    [Test]
+    procedure TestIntfMethod;
   end;
 
   TNullable = class
@@ -62,13 +68,30 @@   TNullable = class
     Other: TNullable;
   end;
 
+  ITestData = interface
+    ['{7F66CDA3-3C98-41AF-A762-8B48FEBF8700}']
+    function GetData: string;
+    property Data: string read GetData;
+  end;
+
+  TTestData = class(TInterfacedObject, ITestData)
+    function GetData: string;
+  end;
+
 implementation
 
 uses
+  System.Rtti,
   System.SysUtils,
   Sempare.Template.Context,
   Sempare.Template;
 
+{ TTestData }
+function TTestData.GetData: string;
+begin
+  exit('hello');
+end;
+
 { TTestTemplateDeref }
 
 procedure TTestTemplateDeref.Test<T>(const AValue: T; const AExpect: string; const ATemplate: string);
@@ -129,6 +152,28 @@ procedure TTestTemplateDeref.TestExprDrefef;
   Test(rec, '''before  123 after ''', '''before <% suffix := ''def'' %> <% a.b[''abc'' + suffix] %> after ''');
 end;
 
+procedure TTestTemplateDeref.TestIntfMethod;
+var
+  LIntf: ITestData;
+begin
+  LIntf := TTestData.Create;
+
+  Assert.AreEqual('hello', Template.Eval('<% _.GetData() %>', TValue.From<ITestData>(LIntf)));
+
+end;
+
+procedure TTestTemplateDeref.TestIntfProperty;
+var
+  LIntf: ITestData;
+begin
+  LIntf := TTestData.Create;
+  Assert.WillRaise(
+    procedure
+    begin
+      Assert.AreEqual('hello', Template.Eval('<% _.data %>', TValue.From<ITestData>(LIntf)));
+    end);
+end;
+
 procedure TTestTemplateDeref.TestSimpleDrefef;
 begin
   Assert.IsNotNull(Template.parse('before <% a.b %> after '));