/// <summary> /// If there is a MemberInitExpression 'new Person { ID = p.ID, Friend = new Person { ID = p.Friend.ID }}' /// or a NewExpression 'new { ID = p.ID, Friend = new { ID = p.Friend.ID }}', /// this method validates against the RHS of the member assignment, the expression "p.ID" for example. /// </summary> /// <param name="expressionToAssign">The expression to validate.</param> /// <param name="initType">Type of the MemberInit or the New expression.</param> /// <param name="previousNested">The outer nested initializer of the current initializer we are checking.</param> /// <returns>true if the expression to assign is fine; false otherwise.</returns> private bool CheckCompatibleAssignmentExpression(Expression expressionToAssign, Type initType, ref MemberAssignmentAnalysis previousNested) { MemberAssignmentAnalysis nested = MemberAssignmentAnalysis.Analyze(this.entity, expressionToAssign); if (nested.MultiplePathsFound) { this.multiplePathsFound = true; return(false); } // When we're visiting a nested entity initializer, we're exactly one level above that. Exception incompatibleException = nested.CheckCompatibleAssignments(initType, ref previousNested); if (incompatibleException != null) { this.incompatibleAssignmentsException = incompatibleException; return(false); } if (this.pathFromEntity.Count == 0) { this.pathFromEntity.AddRange(nested.GetExpressionsToTargetEntity()); } return(true); }
/// <summary>Analyzes the specified member-init expression.</summary> /// <param name="mie">Expression to analyze.</param> /// <param name="pb">Path-tracking object to store analysis in.</param> /// <param name="context">Context of expression to analyze.</param> internal static void Analyze(MemberInitExpression mie, SelectExpandPathBuilder pb, DataServiceContext context) { Debug.Assert(mie != null, "mie != null"); var epa = new EntityProjectionAnalyzer(pb, mie.Type, context); MemberAssignmentAnalysis targetEntityPath = null; foreach (MemberBinding mb in mie.Bindings) { MemberAssignment ma = mb as MemberAssignment; epa.Visit(ma.Expression); if (ma != null) { var analysis = MemberAssignmentAnalysis.Analyze(pb.ParamExpressionInScope, ma.Expression); if (analysis.IncompatibleAssignmentsException != null) { throw analysis.IncompatibleAssignmentsException; } // Note that an "empty" assignment on the binding is not checked/handled, // because the funcletizer would have turned that into a constant // in the tree, the visit earlier in this method would have thrown // an exception at finding a constant in an entity projection. // // We do account however for failing to find a reference off the // parameter entry to detect errors like this: new ET() { Ref = e } // Here it looks like the new ET should be the parent of 'e', but // there is nothing in scope that represents that. // // This also explains while error messages might be a bit misleading // in this case (because they reference a constant when the user // hasn't included any). Type targetType = ClientTypeUtil.GetMemberType(ma.Member); Expression[] lastExpressions = analysis.GetExpressionsBeyondTargetEntity(); if (lastExpressions.Length == 0) { throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(targetType, ma.Expression)); } MemberExpression lastExpression = lastExpressions[lastExpressions.Length - 1] as MemberExpression; Debug.Assert( !analysis.MultiplePathsFound, "!analysis.MultiplePathsFound -- the initilizer has been visited, and cannot be empty, and expressions that can combine paths should have thrown exception during initializer analysis"); #if DEBUG Debug.Assert( lastExpression != null, "lastExpression != null -- the initilizer has been visited, and cannot be empty, and the only expressions that are allowed can be formed off the parameter, so this is always correlatd"); #endif analysis.CheckCompatibleAssignments(mie.Type, ref targetEntityPath); // For DataServiceStreamLink, the last expression will be a constant expression. Hence we won't be comparing name checks and entity checks for those type of bindings if (lastExpression != null) { if (lastExpression.Member.Name != ma.Member.Name) { throw new NotSupportedException(Strings.ALinq_PropertyNamesMustMatchInProjections(lastExpression.Member.Name, ma.Member.Name)); } // Unless we're initializing an entity, we should not traverse into the parameter in scope. bool targetIsEntity = ClientTypeUtil.TypeOrElementTypeIsEntity(targetType); bool sourceIsEntity = ClientTypeUtil.TypeOrElementTypeIsEntity(lastExpression.Type); if (sourceIsEntity && !targetIsEntity) { throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjection(targetType, ma.Expression)); } } } } }