public void Bind()
{
Expression <Func <IEnumerable <object>, int> > e1 = x => 0;
var method = ExpressionMethodBinder.Bind(typeof(Source), "Test2", null, new Expression[] { Expression.Constant(e1), Expression.Constant(1) });
Assert.NotNull(method);
}
public void SelectManyBind()
{
PetOwner[] petOwners =
{ new PetOwner {
Name = "Higa",
Pets = new List <string> {
"Scruffy", "Sam"
}
},
new PetOwner {
Name = "Ashkenazi",
Pets = new List <string> {
"Walker", "Sugar"
}
},
new PetOwner {
Name = "Price",
Pets = new List <string> {
"Scratches", "Diesel"
}
},
new PetOwner {
Name = "Hines",
Pets = new List <string> {
"Dusty"
}
} };
Expression <Func <PetOwner, List <string> > > e2 = petOwner => petOwner.Pets;
Expression <Func <PetOwner, string, string> > e3 = (petOwner, petName) => petName + petOwner;
var method = ExpressionMethodBinder.Bind(typeof(Enumerable), "SelectMany", null, new Expression[]
{
Expression.Constant(petOwners), e2, e3
});
Assert.NotNull(method);
}
private Expression VisitMethodCall(ODataMethodCallExpression node)
{
var functionName = node.MethodName.ToLowerInvariant();
switch (functionName)
{
case "contains":
{
var right = Visit(node.Arguments[0]);
var left = Visit(node.Arguments[1]);
return(Expression.Call(right, MethodProvider.ContainsMethod, new[] { left }));
}
case "endswith":
{
var right = Visit(node.Arguments[1]);
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.EndsWithMethod, new[] { right }));
}
case "startswith":
{
var right = Visit(node.Arguments[1]);
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.StartsWithMethod, new[] { right }));
}
case "length":
{
var left = Visit(node.Arguments[0]);
return(Expression.Property(left, MethodProvider.LengthProperty));
}
case "indexof":
{
var right = Visit(node.Arguments[1]);
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.IndexOfMethod, new[] { right }));
}
case "substring":
{
if (node.Arguments.Length == 3)
{
return(Expression.Call(Visit(node.Arguments[0]), MethodProvider.SubstringMethodWithTwoArg, new[] { Visit(node.Arguments[1]), Visit(node.Arguments[2]) }));
}
if (node.Arguments.Length == 2)
{
return(Expression.Call(Visit(node.Arguments[0]), MethodProvider.SubstringMethodWithOneArg, new[] { Visit(node.Arguments[1]) }));
}
throw new NotSupportedException(); //Нет перегрузки для данного метода
}
case "tolower":
{
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.ToLowerMethod));
}
case "toupper":
{
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.ToUpperMethod));
}
case "trim":
{
var left = Visit(node.Arguments[0]);
return(Expression.Call(left, MethodProvider.TrimMethod));
}
case "hour":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.HourProperty));
}
case "minute":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.MinuteProperty));
}
case "second":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.SecondProperty));
}
case "day":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.DayProperty));
}
case "month":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.MonthProperty));
}
case "year":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Property(left, MethodProvider.YearProperty));
}
case "round":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Call(left.Type == typeof(double) ? MethodProvider.DoubleRoundMethod : MethodProvider.DecimalRoundMethod, new[] { left }));
}
case "floor":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Call(left.Type == typeof(double) ? MethodProvider.DoubleFloorMethod : MethodProvider.DecimalFloorMethod, new[] { left }));
}
case "ceiling":
{
var left = Visit(node.Arguments[0]);
if (left.Type.IsNullableType())
{
left = Expression.Property(left, "Value");
}
return(Expression.Call(left.Type == typeof(double) ? MethodProvider.DoubleCeilingMethod : MethodProvider.DecimalCeilingMethod, new[] { left }));
}
case "concat":
{
var right = Visit(node.Arguments[1]);
var left = Visit(node.Arguments[0]);
return(Expression.Add(left, right, MethodProvider.ConcatMethod));
}
case "replace":
{
return(Expression.Call(Visit(node.Arguments[0]), MethodProvider.ReplaceMethod, new[] { Visit(node.Arguments[1]), Visit(node.Arguments[2]) }));
}
case "sum":
case "average":
{
var context = Visit(node.Context);
var genericArguments = context.Type.GetTypeGenericArguments();
var arguments = node.Arguments.Select(argument => argument.NodeType == ExpressionType.Lambda ? VisitLambda((ODataLambdaExpression)argument, genericArguments[0]) : Visit(argument)).ToList();
arguments.Insert(0, context);
var type = context.Type.IsIQueryable() ? typeof(Queryable) : typeof(Enumerable);
return(Expression.Call(type, functionName, arguments.Count == 1 ? Type.EmptyTypes : genericArguments, arguments.ToArray()));
}
case "min":
case "max":
case "selectmany":
{
var context = Visit(node.Context);
var genericArguments = context.Type.GetGenericArguments();
var arguments = node.Arguments.Select(argument => argument.NodeType == ExpressionType.Lambda ? VisitLambda((ODataLambdaExpression)argument, genericArguments[0]) : Visit(argument)).ToList();
arguments.Insert(0, context);
var type = context.Type.IsIQueryable() ? typeof(Queryable) : typeof(Enumerable);
var expr = ExpressionMethodBinder.Bind(type, functionName, null, arguments.ToArray());
return(expr);
}
case "groupby":
case "orderby":
case "orderbydescending":
case "thenby":
case "thenbydescending":
case "select":
{
var context = Visit(node.Context);
var genericArguments = context.Type.GetTypeGenericArguments().ToList();
var lambda = (LambdaExpression)VisitLambda((ODataLambdaExpression)node.Arguments[0], genericArguments[0]);
genericArguments.Add(lambda.ReturnType);
var type = context.Type.IsIQueryable() ? typeof(Queryable) : typeof(Enumerable);
return(Expression.Call(type, functionName, genericArguments.ToArray(), new[] { context, lambda }));
}
case "any":
case "all":
case "first":
case "where":
case "take":
case "skip":
case "distinct":
case "last":
case "lastordefault":
case "single":
case "singleordefault":
case "defaultifempty":
case "count":
case "longcount":
case "firstordefault":
{
var context = Visit(node.Context);
var genericArguments = context.Type.GetTypeGenericArguments();
var arguments = node.Arguments.Select(argument => argument.NodeType == ExpressionType.Lambda ? VisitLambda((ODataLambdaExpression)argument, genericArguments[0]) : Visit(argument)).ToList();
arguments.Insert(0, context);
var type = context.Type.IsIQueryable() ? typeof(Queryable) : typeof(Enumerable);
return(Expression.Call(type, functionName, genericArguments, arguments.ToArray()));
}
case "isof":
{
//ParameterExpression parameter = null;
Expression genericParameter = null;
object typeName = null;
if (node.Arguments.Length == 1)
{
genericParameter = _parameters.Select(x => x.Value).FirstOrDefault();
typeName = ((ConstantExpression)Visit(node.Arguments[0])).Value;
}
if (node.Arguments.Length == 2)
{
var arguments = node.Arguments.Select(Visit).ToArray();
genericParameter = arguments[0];
typeName = ((ConstantExpression)arguments[1]).Value;
}
if (genericParameter != null)
{
var type = typeName is Type ? (Type)typeName : null;
if (type == null && KnownAssembly != null)
{
type = KnownAssembly.GetType((string)typeName);
}
return(Expression.TypeIs(genericParameter, type));
}
throw new NotSupportedException(node.DebugView());
}
case "cast":
{
if (node.Arguments.Length == 1)
{
var parameter = _parameters.Select(x => x.Value).FirstOrDefault();
if (parameter != null)
{
var type = (Type)((ConstantExpression)Visit(node.Arguments[0])).Value;
return(Expression.TypeAs(parameter, type));
}
}
if (node.Arguments.Length == 2)
{
var arguments = node.Arguments.Select(Visit).ToArray();
return(Expression.TypeAs(arguments[0], (Type)((ConstantExpression)arguments[1]).Value));
}
throw new NotSupportedException(node.DebugView());
}
case "substringof":
{
var right = Visit(node.Arguments[1]);
var left = Visit(node.Arguments[0]);
return(Expression.Call(right, MethodProvider.ContainsMethod, new[] { left }));
}
default:
{
if (node.Context != null)
{
var context = Visit(node.Context);
var arguments = node.Arguments.Select(Visit).ToList();
var expr = ExpressionMethodBinder.Bind(context.Type, functionName, context, arguments.ToArray());
if (expr == null)
{
throw new Exception(String.Format("Can't find a method: {0}", node.DebugView()));
}
return(expr);
}
if (MethodProvider.UserFunctions.ContainsKey(node.MethodName))
{
var arguments = node.Arguments.Select(Visit).ToArray();
var methodExpression = ExpressionMethodBinder.Bind(
MethodProvider.UserFunctions[node.MethodName], node.MethodName, null, arguments);
if (methodExpression == null)
{
throw new Exception(String.Format("Can't find a method: {0}", node.DebugView()));
}
return(methodExpression);
}
throw new NotSupportedException(String.Format("Can't find a method: {0}", node.DebugView()));
}
}
}