internal override Expression VisitMemberAccess(MemberExpression m)
{
Debug.Assert(m != null, "m != null");
this.leafExpressionIsMemberAccess = true;
// Only allowed to project entities
if (!ClientTypeUtil.TypeOrElementTypeIsEntity(m.Expression.Type) ||
IsCollectionProducingExpression(m.Expression))
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, m.ToString()));
}
PropertyInfo pi;
Expression boundTarget;
if (ResourceBinder.PatternRules.MatchNonPrivateReadableProperty(m, out pi, out boundTarget))
{
Expression e = base.VisitMemberAccess(m);
Type convertedType;
ResourceBinder.StripTo <Expression>(m.Expression, out convertedType);
this.builder.AppendPropertyToPath(pi, convertedType, this.context);
this.leafExpressionIsMemberAccess = false;
return(e);
}
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, m.ToString()));
}
internal override Expression VisitUnary(UnaryExpression u)
{
Debug.Assert(u != null, "u != null");
// Perfectly assignable conversions are OK. VB.NET compilers
// inserts these to exactly match method signatures, for example.
if (ResourceBinder.PatternRules.MatchConvertToAssignable(u) || (u.NodeType == ExpressionType.TypeAs && this.leafExpressionIsMemberAccess))
{
return(base.VisitUnary(u));
}
if ((u.NodeType == ExpressionType.Convert) || (u.NodeType == ExpressionType.ConvertChecked))
{
Type sourceType = Nullable.GetUnderlyingType(u.Operand.Type) ?? u.Operand.Type;
Type targetType = Nullable.GetUnderlyingType(u.Type) ?? u.Type;
// when projecting known entity types, will allow convert expressions of primitive types.
if (PrimitiveType.IsKnownType(sourceType) && PrimitiveType.IsKnownType(targetType))
{
return(base.Visit(u.Operand));
}
}
// In V3 while we support TypeAs conversions, we only support TypeAs before a MemberAccess and not TypeAs as the last operation
// i.e. we support "Manager = (p as Employee).Manager" (see VisitMemberAccess for detail), but we dont support "Manager = (p as Manager)"
// Note that the server also doesn't support a property path which ends with a type identifier.
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, u.ToString()));
}
internal override Expression VisitMemberInit(MemberInitExpression init)
{
if (!ClientTypeUtil.TypeOrElementTypeIsEntity(init.Type))
{
// MemberInit to a complex type is not supported on entity types.
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, init.ToString()));
}
ProjectionAnalyzer.Analyze(init, this.builder, this.context);
return(init);
}
internal override Expression VisitConditional(ConditionalExpression c)
{
var nullCheck = ResourceBinder.PatternRules.MatchNullCheck(this.builder.ParamExpressionInScope, c);
if (nullCheck.Match)
{
this.Visit(nullCheck.AssignExpression);
return(c);
}
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, c.ToString()));
}
internal override NewExpression VisitNew(NewExpression nex)
{
// Allow creation of DataServiceCollection<T> objects in projections
if (ResourceBinder.PatternRules.MatchNewDataServiceCollectionOfT(nex))
{
// It doesn't matter if the DSC is being tracked or not, that has no direct effect on the projections
// But it does matter if the T in DSC<T> is an entity or not. In here we only allow entity types to be used
// for creation of DSC.
if (ClientTypeUtil.TypeOrElementTypeIsEntity(nex.Type))
{
foreach (Expression e in nex.Arguments)
{
// no need to check the constant values here (DataServiceContext, funcs, etc).
if (e.NodeType != ExpressionType.Constant)
{
base.Visit(e);
}
}
return(nex);
}
}
else if (ResourceBinder.PatternRules.MatchNewCollectionOfT(nex))
{
if (!ClientTypeUtil.TypeOrElementTypeIsEntity(nex.Type))
{
foreach (Expression e in nex.Arguments)
{
// no need to check the constant values here (DataServiceContext, funcs, etc).
if (e.NodeType != ExpressionType.Constant)
{
base.Visit(e);
}
}
return(nex);
}
}
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, nex.ToString()));
}
internal override Expression VisitMethodCall(MethodCallExpression m)
{
// We throw NotSupportedException when IsDisallowedExceptionForMethodCall() is true
// or we have a method call on a non-entity type, for example c.MyCollectionComplexProperty.Select(...)
if ((m.Object != null && (IsDisallowedExpressionForMethodCall(m.Object, this.context.Model) || !ClientTypeUtil.TypeOrElementTypeIsEntity(m.Object.Type))) ||
m.Arguments.Any(a => IsDisallowedExpressionForMethodCall(a, this.context.Model)) ||
(m.Object == null && !ClientTypeUtil.TypeOrElementTypeIsEntity(m.Arguments[0].Type)))
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjection(this.type, m.ToString()));
}
if (ProjectionAnalyzer.IsMethodCallAllowedEntitySequence(m))
{
CheckChainedSequence(m, this.type);
// allow selects for following pattern:
// Orders = c.Orders.Select(o=> new NarrowOrder {...}).ToList();
return(base.VisitMethodCall(m));
}
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, m.ToString()));
}
internal override Expression VisitNewArray(NewArrayExpression na)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, na.ToString()));
}
internal override Expression VisitListInit(ListInitExpression init)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, init.ToString()));
}
internal override Expression VisitInvocation(InvocationExpression iv)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, iv.ToString()));
}
internal override Expression VisitConstant(ConstantExpression c)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, c.ToString()));
}
internal override Expression VisitTypeIs(TypeBinaryExpression b)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, b.ToString()));
}
/// <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));
}
}
}
}
}