/// <summary>
/// Analyzes the specified <paramref name="lambda"/> for selection and updates
/// <paramref name="resource"/>.
/// </summary>
/// <param name="lambda">Lambda expression to analyze.</param>
/// <param name="resource">Resource expression to update.</param>
/// <param name="context">Context of expression to analyze.</param>
private static void AnalyzeResourceExpression(LambdaExpression lambda, ResourceExpression resource, DataServiceContext context)
{
SelectExpandPathBuilder pb = new SelectExpandPathBuilder();
ProjectionAnalyzer.Analyze(lambda, pb, context);
resource.Projection = new ProjectionQueryOptionExpression(lambda.Body.Type, lambda, pb.ProjectionPaths.ToList());
resource.ExpandPaths = pb.ExpandPaths.Union(resource.ExpandPaths, StringComparer.Ordinal).ToList();
resource.RaiseUriVersion(pb.UriVersion);
}
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 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 VisitMethodCall(MethodCallExpression m)
{
if ((m.Object != null && IsDisallowedExpressionForMethodCall(m.Object, this.context.Model)) ||
m.Arguments.Any(a => IsDisallowedExpressionForMethodCall(a, this.context.Model)))
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjection(this.type, m.ToString()));
}
CheckChainedSequence(m, this.type);
if (ProjectionAnalyzer.IsMethodCallAllowedEntitySequence(m))
{
// allow IEnum.Select and IEnum.ToList even if entity type.
return(base.VisitMethodCall(m));
}
if ((m.Object != null ? ClientTypeUtil.TypeOrElementTypeIsEntity(m.Object.Type) : false) ||
m.Arguments.Any(a => ClientTypeUtil.TypeOrElementTypeIsEntity(a.Type)))
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjection(this.type, m.ToString()));
}
return(base.VisitMethodCall(m));
}
internal override Expression VisitMemberInit(MemberInitExpression init)
{
ProjectionAnalyzer.Analyze(init, this.builder, this.context);
return(init);
}
internal override Expression VisitLambda(LambdaExpression lambda)
{
ProjectionAnalyzer.Analyze(lambda, this.builder, this.context);
return(lambda);
}
/// <summary>
/// CODE: x
/// ORIGINAL: Convert(x, t) where t is assignable from typeof(x)
/// ORIGINAL: x as t, where t is assignable from typeof(x)
/// ORIGINAL: and typeof(x) or t are not known primitives unless typeof(x) == t
/// ORIGINAL: and x is not a collection of entity types
/// ORIGINAL: and x is not a enum type
/// NORMALIZED: x
/// </summary>
internal override Expression VisitUnary(UnaryExpression u)
{
UnaryExpression visited = (UnaryExpression)base.VisitUnary(u);
Expression result = visited;
// Note that typically we would record a potential rewrite
// after extracting the conversion, but we avoid doing this
// because it breaks undoing the rewrite by making the non-local
// change circular, ie:
// unary [operand = a]
// becomes
// a <- unary [operand = a]
// So the undoing visits a, then the original unary, then the
// operand and again the unary, the operand, etc.
this.RecordRewrite(u, result);
// Convert(x, t) or x as t, where t is assignable from typeof(x)
if ((visited.NodeType == ExpressionType.Convert || visited.NodeType == ExpressionType.TypeAs) && visited.Type.IsAssignableFrom(visited.Operand.Type))
{
// typeof(x) or t are not known primitives unless typeof(x) == t
if (!PrimitiveType.IsKnownNullableType(visited.Operand.Type) && !PrimitiveType.IsKnownNullableType(visited.Type) || visited.Operand.Type == visited.Type)
{
// x is not a collection of entity types
if (!(ClientTypeUtil.TypeOrElementTypeIsEntity(visited.Operand.Type) && ProjectionAnalyzer.IsCollectionProducingExpression(visited.Operand)))
{
// x is not an enum type
if (!visited.Operand.Type.IsEnum)
{
result = visited.Operand;
}
}
}
}
return(result);
}
