Improve UDF handling in delegation strategy

src/libraries/Microsoft.PowerFx.Core/Functions/Delegation/DelegationStrategies/DelegationValidationStrategy.cs

@@ -1,12 +1,14 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
+using System.Collections.Generic;
 using System.Globalization;
 using System.Security.Authentication.ExtendedProtection;
 using Microsoft.PowerFx.Core.Binding;
 using Microsoft.PowerFx.Core.Binding.BindInfo;
 using Microsoft.PowerFx.Core.Entities;
 using Microsoft.PowerFx.Core.Errors;
+using Microsoft.PowerFx.Core.Functions.Delegation.DelegationMetadata;
 using Microsoft.PowerFx.Core.Localization;
 using Microsoft.PowerFx.Core.Logging.Trackers;
 using Microsoft.PowerFx.Core.Texl.Builtins;
@@ -18,17 +20,17 @@ namespace Microsoft.PowerFx.Core.Functions.Delegation.DelegationStrategies
 {
     internal interface ICallNodeDelegatableNodeValidationStrategy
     {
-        bool IsValidCallNode(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null);
+        bool IsValidCallNode(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null, bool nodeInheritsRowScope = false);
     }
 
     internal interface IDottedNameNodeDelegatableNodeValidationStrategy
     {
-        bool IsValidDottedNameNode(DottedNameNode node, TexlBinding binding, OperationCapabilityMetadata metadata, IOpDelegationStrategy opDelStrategy);
+        bool IsValidDottedNameNode(DottedNameNode node, TexlBinding binding, OperationCapabilityMetadata metadata, IOpDelegationStrategy opDelStrategy, bool nodeInheritsRowScope = false);
     }
 
     internal interface IFirstNameNodeDelegatableNodeValidationStrategy
     {
-        bool IsValidFirstNameNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy);
+        bool IsValidFirstNameNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy, bool nodeInheritsRowScope = false);
     }
 
     internal class DelegationValidationStrategy
@@ -175,13 +177,13 @@ private OperationCapabilityMetadata GetScopedOperationCapabilityMetadata(IDelega
             return delegationMetadata.FilterDelegationMetadata;
         }
 
-        public bool IsValidDottedNameNode(DottedNameNode node, TexlBinding binding, OperationCapabilityMetadata metadata, IOpDelegationStrategy opDelStrategy)
+        public bool IsValidDottedNameNode(DottedNameNode node, TexlBinding binding, OperationCapabilityMetadata metadata, IOpDelegationStrategy opDelStrategy, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(binding);
             Contracts.AssertValueOrNull(opDelStrategy);
 
-            var isRowScoped = binding.IsRowScope(node);
+            var isRowScoped = binding.IsRowScope(node) || nodeInheritsRowScope;
             if (!isRowScoped)
             {
                 return IsValidNonRowScopedDottedNameNode(node, binding, metadata, opDelStrategy);
@@ -262,13 +264,13 @@ public bool IsValidDottedNameNode(DottedNameNode node, TexlBinding binding, Oper
             return opDelStrategy?.IsOpSupportedByColumn(entityCapabilityMetadata, node, entityColumnPath, binding) ?? true;
         }
 
-        public bool IsValidFirstNameNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy)
+        public bool IsValidFirstNameNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(binding);
             Contracts.AssertValueOrNull(opDelStrategy);
 
-            var isRowScoped = binding.IsRowScope(node);
+            var isRowScoped = binding.IsRowScope(node) || nodeInheritsRowScope;
             var isValid = IsValidAsyncOrImpureNode(node, binding);
             if (isValid && !isRowScoped)
             {
@@ -312,12 +314,12 @@ private IDelegationMetadata GetCapabilityMetadata(FirstNameInfo info)
         }
 
         // Verifies if provided column node supports delegation.
-        protected bool IsDelegatableColumnNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy, DelegationCapability capability)
+        protected bool IsDelegatableColumnNode(FirstNameNode node, TexlBinding binding, IOpDelegationStrategy opDelStrategy, DelegationCapability capability, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(binding);
             Contracts.AssertValueOrNull(opDelStrategy);
-            Contracts.Assert(binding.IsRowScope(node));
+            Contracts.Assert(binding.IsRowScope(node) || nodeInheritsRowScope);
 
             var firstNameInfo = binding.GetInfo(node.AsFirstName());
             if (firstNameInfo == null)
@@ -359,7 +361,7 @@ protected bool IsDelegatableColumnNode(FirstNameNode node, TexlBinding binding,
             return true;
         }
 
-        public virtual bool IsValidCallNode(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null)
+        public virtual bool IsValidCallNode(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null, bool nodeInheritsRowScope = false)
         {
             // Functions may have their specific CallNodeDelegationStrategies (i.e. AsType, User)
             // so, if available, we need to ensure we use their specific delegation strategy.
@@ -370,13 +372,13 @@ public virtual bool IsValidCallNode(CallNode node, TexlBinding binding, Operatio
             if (function != null && function != Function)
             {
                 // We need to keep track of the tracking function for delegation tracking telemetry to be consistent.
-                return function.GetCallNodeDelegationStrategy().IsValidCallNode(node, binding, metadata, trackingFunction ?? Function);
+                return function.GetCallNodeDelegationStrategy().IsValidCallNode(node, binding, metadata, trackingFunction ?? Function, nodeInheritsRowScope: nodeInheritsRowScope);
             }
 
-            return IsValidCallNodeInternal(node, binding, metadata, trackingFunction ?? Function);
+            return IsValidCallNodeInternal(node, binding, metadata, trackingFunction ?? Function, nodeInheritsRowScope: nodeInheritsRowScope);
         }
 
-        protected bool IsValidCallNodeInternal(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null)
+        protected bool IsValidCallNodeInternal(CallNode node, TexlBinding binding, OperationCapabilityMetadata metadata, TexlFunction trackingFunction = null, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(binding);
@@ -393,7 +395,7 @@ protected bool IsValidCallNodeInternal(CallNode node, TexlBinding binding, Opera
             }
 
             // If the node is not row scoped and it's valid then it can be delegated.
-            var isRowScoped = binding.IsRowScope(node);
+            var isRowScoped = binding.IsRowScope(node) || nodeInheritsRowScope;
             if (!isRowScoped)
             {
                 return true;
@@ -405,9 +407,16 @@ protected bool IsValidCallNodeInternal(CallNode node, TexlBinding binding, Opera
                 SuggestDelegationHint(node, binding, warning, new object[] { callInfo?.Function.Name });
             }
 
-            if (callInfo?.Function != null && ((TexlFunction)callInfo.Function).IsRowScopedServerDelegatable(node, binding, metadata))
+            if (callInfo?.Function != null && ((TexlFunction)callInfo.Function).IsRowScopedServerDelegatable(node, binding, metadata, nodeInheritsRowScope: nodeInheritsRowScope))
             {
                 return true;
+            }
+
+            if (callInfo?.Function is UserDefinedFunction udf &&
+                ((FilterFunction)trackingFunction).IsValidDelegatableFilterPredicateNode(udf.Binding.Top, udf.Binding, metadata as FilterOpMetadata, nodeInheritsRowScope: isRowScoped))
+            {
+                udf.SetSupportRowScopedServerDelegation(true);
+                return true;
             }
 
             var telemetryMessage = string.Format(CultureInfo.InvariantCulture, "Kind:{0}, isRowScoped:{1}", node.Kind, isRowScoped);

src/libraries/Microsoft.PowerFx.Core/Functions/Delegation/DelegationStrategies/IOpDelegationStrategy.cs

@@ -13,6 +13,6 @@ internal interface IOpDelegationStrategy
 
         bool IsOpSupportedByTable(OperationCapabilityMetadata metadata, TexlNode node, TexlBinding binder);
 
-        bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding);
+        bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, bool nodeInheritsRowScope = false);
     }
 }

src/libraries/Microsoft.PowerFx.Core/Functions/Delegation/DelegationStrategies/InOpDelegationStrategy.cs

@@ -25,7 +25,7 @@ public InOpDelegationStrategy(BinaryOpNode node, TexlFunction function)
             _binaryOpNode = node;
         }
 
-        public override bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding)
+        public override bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(metadata);
@@ -52,7 +52,7 @@ public override bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadat
                 return false;
             }
 
-            var isRowScopedOrLambda = IsRowScopedOrLambda(binding, node, info, columnName, metadata);
+            var isRowScopedOrLambda = IsRowScopedOrLambda(binding, node, info, columnName, metadata) || nodeInheritsRowScope;
             if (!isRowScopedOrLambda)
             {
                 return false;

src/libraries/Microsoft.PowerFx.Core/Functions/Delegation/DelegationStrategies/OpDelegationStrategy.cs

@@ -80,7 +80,7 @@ public virtual bool IsOpSupportedByTable(OperationCapabilityMetadata metadata, T
         }
 
         // Verifies if given kind of node is supported by function delegation.
-        private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, IOpDelegationStrategy opDelStrategy, bool isRHSNode)
+        private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, IOpDelegationStrategy opDelStrategy, bool isRHSNode, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(metadata);
@@ -112,7 +112,7 @@ private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata
             }
 
             // Non row-scope, non async, pure nodes should always be valid because we can calculate value in runtime before delegation.
-            if (!binding.IsRowScope(node) && !binding.IsAsync(node) && binding.IsPure(node))
+            if (!binding.IsRowScope(node) && !binding.IsAsync(node) && binding.IsPure(node) && !nodeInheritsRowScope)
             {
                 return true;
             }
@@ -138,7 +138,7 @@ private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata
                         }
 
                         var cNodeValStrategy = _function.GetCallNodeDelegationStrategy();
-                        return cNodeValStrategy.IsValidCallNode(node.AsCall(), binding, metadata);
+                        return cNodeValStrategy.IsValidCallNode(node.AsCall(), binding, metadata, nodeInheritsRowScope: nodeInheritsRowScope);
                     }
 
                 case NodeKind.FirstName:
@@ -156,7 +156,7 @@ private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata
 
                         var unaryopNode = node.AsUnaryOpLit();
                         var unaryOpNodeDelegationStrategy = _function.GetOpDelegationStrategy(unaryopNode.Op);
-                        return unaryOpNodeDelegationStrategy.IsSupportedOpNode(unaryopNode, metadata, binding);
+                        return unaryOpNodeDelegationStrategy.IsSupportedOpNode(unaryopNode, metadata, binding, nodeInheritsRowScope: nodeInheritsRowScope);
                     }
 
                 case NodeKind.BinaryOp:
@@ -172,7 +172,7 @@ private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata
                         var binaryOpDelStrategy = (opDelStrategy as BinaryOpDelegationStrategy).VerifyValue();
                         Contracts.Assert(binaryOpNode.Op == binaryOpDelStrategy.Op);
 
-                        if (!opDelStrategy.IsSupportedOpNode(node, metadata, binding))
+                        if (!opDelStrategy.IsSupportedOpNode(node, metadata, binding, nodeInheritsRowScope: nodeInheritsRowScope))
                         {
                             SuggestDelegationHint(binaryOpNode, binding);
                             return false;
@@ -263,7 +263,7 @@ private bool DoCoercionCheck(BinaryOpNode binaryOpNode, OperationCapabilityMetad
             return true;
         }
 
-        public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding)
+        public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(metadata);
@@ -298,13 +298,13 @@ public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata
                 return false;
             }
 
-            if (!IsSupportedNode(binaryOpNode.Left, metadata, binding, opDelStrategy, false))
+            if (!IsSupportedNode(binaryOpNode.Left, metadata, binding, opDelStrategy, false, nodeInheritsRowScope))
             {
                 SuggestDelegationHint(node, binding);
                 return false;
             }
 
-            if (!IsSupportedNode(binaryOpNode.Right, metadata, binding, opDelStrategy, true))
+            if (!IsSupportedNode(binaryOpNode.Right, metadata, binding, opDelStrategy, true, nodeInheritsRowScope))
             {
                 SuggestDelegationHint(node, binding);
                 return false;

src/libraries/Microsoft.PowerFx.Core/Functions/Delegation/DelegationStrategies/UnaryOpDelegationStrategy.cs

@@ -69,14 +69,14 @@ public virtual bool IsOpSupportedByTable(OperationCapabilityMetadata metadata, T
             return true;
         }
 
-        private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, IOpDelegationStrategy opDelStrategy)
+        private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, IOpDelegationStrategy opDelStrategy, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(metadata);
             Contracts.AssertValue(binding);
             Contracts.AssertValue(opDelStrategy);
 
-            if (!binding.IsRowScope(node))
+            if (!binding.IsRowScope(node) && nodeInheritsRowScope)
             {
                 return true;
             }
@@ -150,7 +150,7 @@ private bool IsSupportedNode(TexlNode node, OperationCapabilityMetadata metadata
             return false;
         }
 
-        public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding)
+        public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata metadata, TexlBinding binding, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(node);
             Contracts.AssertValue(metadata);
@@ -179,7 +179,7 @@ public virtual bool IsSupportedOpNode(TexlNode node, OperationCapabilityMetadata
                 return false;
             }
 
-            return IsSupportedNode(unaryOpNode.Child, metadata, binding, opDelStrategy);
+            return IsSupportedNode(unaryOpNode.Child, metadata, binding, opDelStrategy, nodeInheritsRowScope);
         }
     }
 }

src/libraries/Microsoft.PowerFx.Core/Functions/TexlFunction.cs

@@ -945,12 +945,12 @@ public virtual bool SupportsPaging(CallNode callNode, TexlBinding binding)
 
         // Returns true if function is row scoped and supports delegation.
         // Needs to be overriden by functions (For example, IsBlank) which are not server delegatable themselves but can become one when scoped inside a delegatable function.
-        public virtual bool IsRowScopedServerDelegatable(CallNode callNode, TexlBinding binding, OperationCapabilityMetadata metadata)
+        public virtual bool IsRowScopedServerDelegatable(CallNode callNode, TexlBinding binding, OperationCapabilityMetadata metadata, bool nodeInheritsRowScope = false)
         {
             Contracts.AssertValue(callNode);
             Contracts.AssertValue(binding);
 
-            if (!binding.IsRowScope(callNode))
+            if (!binding.IsRowScope(callNode) && !nodeInheritsRowScope)
             {
                 return false;
             }

src/libraries/Microsoft.PowerFx.Core/Functions/UserDefinedFunction.cs

@@ -12,6 +12,7 @@
 using Microsoft.PowerFx.Core.Binding.BindInfo;
 using Microsoft.PowerFx.Core.Entities;
 using Microsoft.PowerFx.Core.Errors;
+using Microsoft.PowerFx.Core.Functions.Delegation;
 using Microsoft.PowerFx.Core.Functions.FunctionArgValidators;
 using Microsoft.PowerFx.Core.Glue;
 using Microsoft.PowerFx.Core.IR;
@@ -44,7 +45,9 @@ internal class UserDefinedFunction : TexlFunction, IExternalPageableSymbol, IExt
 
         public bool IsPageable => _binding.IsPageable(_binding.Top);
 
-        public bool IsDelegatable => _binding.IsDelegatable(_binding.Top);
+        public bool IsDelegatable => _binding.IsDelegatable(_binding.Top);
+
+        public bool SupportsRowScopedServerDelegation;
 
         public override bool IsServerDelegatable(CallNode callNode, TexlBinding binding)
         {
@@ -53,7 +56,12 @@ public override bool IsServerDelegatable(CallNode callNode, TexlBinding binding)
             Contracts.Assert(binding.GetInfo(callNode).Function is UserDefinedFunction udf && udf.Binding != null);
 
             return base.IsServerDelegatable(callNode, binding) || IsDelegatable;
-        }
+        }
+
+        public override bool IsRowScopedServerDelegatable(CallNode callNode, TexlBinding binding, OperationCapabilityMetadata metadata, bool nodeInheritsRowScope = false)
+        {
+            return SupportsRowScopedServerDelegation;
+        }
 
         public override bool SupportsParamCoercion => true;
 
@@ -92,7 +100,8 @@ public UserDefinedFunction(string functionName, DType returnType, TexlNode body,
             this._args = args;
             this._isImperative = isImperative;
 
-            this.UdfBody = body;
+            this.UdfBody = body;
+            this.SupportsRowScopedServerDelegation = false;
         }
 
         /// <summary>
@@ -370,8 +379,13 @@ internal static bool IsRestrictedType(FormulaType ft)
             }
 
             return false;
-        }
-
+        }
+
+        internal void SetSupportRowScopedServerDelegation(bool value)
+        {
+            SupportsRowScopedServerDelegation = value;
+        }
+
         /// <summary>
         /// NameResolver that combines global named resolver and params for user defined function.
         /// </summary>

src/libraries/Microsoft.PowerFx.Core/Texl/Builtins/AsType.cs

@@ -106,7 +106,7 @@ private static bool IsExternalSource(object externalDataSource)
                 tDsInfo is IExternalTabularDataSource; 
         }
 
-        public override bool IsRowScopedServerDelegatable(CallNode callNode, TexlBinding binding, OperationCapabilityMetadata metadata)
+        public override bool IsRowScopedServerDelegatable(CallNode callNode, TexlBinding binding, OperationCapabilityMetadata metadata, bool nodeInheritsRowScope = false)
         {
             return metadata.IsDelegationSupportedByTable(DelegationCapability.AsType);
         }