make enumerating datasets consistent with other objects using in/of on for loops

Author: darnocian

src/Sempare.Template.Evaluate.pas

@@ -503,7 +503,10 @@ procedure TEvaluationTemplateVisitor.Visit(const AStmt: IForInStmt);
 
     while not LDataSetEOFProperty.GetValue(LObj).AsBoolean and ((LLimit = -1) or (LLoops < LLimit)) do
     begin
-      FStackFrames.peek[LVariableName] := LIdx;
+      if AStmt.ForOp = foIn then
+        FStackFrames.peek[LVariableName] := LIdx - 1
+      else
+        FStackFrames.peek[LVariableName] := LLoopExpr;
       if HandleLoop then
         break;
       LDataSetNextMethod.Invoke(LObj, []);

tests/Sempare.Template.TestFor.pas

@@ -147,19 +147,38 @@ procedure TTestTemplateFor.TestDataSet;
 var
   ds: TDataSet;
 begin
+  // traditional
   ds := CreateMockUsersTable();
   try
     Assert.AreEqual('joe pete jane ', //
       Template.Eval('<% for i in _ %><% _[''name''] %> <%end%>', ds));
   finally
     ds.Free;
   end;
+  // index in
+  ds := CreateMockUsersTable();
+  try
+    Assert.AreEqual('0 1 2 ', //
+      Template.Eval('<% for i in _ %><% i %> <%end%>', ds));
+  finally
+    ds.Free;
+  end;
+  // index of
+  ds := CreateMockUsersTable();
+  try
+    Assert.AreEqual('joe pete jane ', //
+      Template.Eval('<% for i of _ %><% i[''name''] %> <%end%>', ds));
+  finally
+    ds.Free;
+  end;
+
 end;
 
 procedure TTestTemplateFor.TestDataSetWithEvent;
 var
   ds: TDataSet;
 begin
+  // traditional
   ds := CreateMockUsersTable();
   try
     Assert.AreEqual('<ul><li>joe</li><li>pete</li><li>jane</li></ul>', //
@@ -175,6 +194,40 @@ procedure TTestTemplateFor.TestDataSetWithEvent;
   finally
     ds.Free;
   end;
+
+  // using index in
+  ds := CreateMockUsersTable();
+  try
+    Assert.AreEqual('<ul><li>0</li><li>1</li><li>2</li></ul>', //
+      Template.Eval('<% for i in _ %><li><% i %></li><% onbegin%><ul><%onend%></ul><%end%>', ds));
+
+    ds.Delete();
+    ds.Delete();
+    ds.Delete();
+
+    Assert.AreEqual('<h1>No values</h1>', //
+      Template.Eval('<% for i in _ %><li><% i %></li><% onbegin%><ul><%onend%></ul><% onempty%><h1>No values</h1><%end%>', ds));
+
+  finally
+    ds.Free;
+  end;
+
+  // using index of
+  ds := CreateMockUsersTable();
+  try
+    Assert.AreEqual('<ul><li>joe</li><li>pete</li><li>jane</li></ul>', //
+      Template.Eval('<% for i of _ %><li><% i[''name''] %></li><% onbegin%><ul><%onend%></ul><%end%>', ds));
+
+    ds.Delete();
+    ds.Delete();
+    ds.Delete();
+
+    Assert.AreEqual('<h1>No values</h1>', //
+      Template.Eval('<% for i in _ %><li><% [''name''] %></li><% onbegin%><ul><%onend%></ul><% onempty%><h1>No values</h1><%end%>', ds));
+
+  finally
+    ds.Free;
+  end;
 end;
 
 procedure TTestTemplateFor.TestDataSetCount;