internal Expression <Func <TIn, MapContext, TOut> > GetProjector()
{
var inObjPrm = Expression.Parameter(_inType);
var mapContextPrm = Expression.Parameter(typeof(MapContext));
var memberBindings = new List <MemberBinding>();
foreach (var outMember in _outMembers)
{
LambdaExpression expression;
if (_expressions.TryGetValue(outMember, out expression))
{
if (expression == null)
{
continue;
}
var prv = new ParameterReplaceVisitor(new Dictionary <ParameterExpression, Expression> {
{ expression.Parameters[0], inObjPrm },
{ expression.Parameters[1], mapContextPrm }
});
memberBindings.Add(Expression.Bind(outMember.MemberInfo, prv.Visit(expression.Body)));
}
else
{
var memberBinding = CreateMemberBinding(outMember, inObjPrm, mapContextPrm);
if (memberBinding != null)
{
memberBindings.Add(memberBinding);
}
}
}
var memberInit = Expression.MemberInit(Expression.New(_outType), memberBindings);
return(Expression.Lambda <Func <TIn, MapContext, TOut> >(memberInit, inObjPrm, mapContextPrm));
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (node.Method.DeclaringType == typeof(MapContext) && node.Method.Name == "Map")
{
var inPrm = node.Arguments[0];
var inType = inPrm.Type;
var outType = node.Method.ReturnType;
if (_includes != null)
{
var path = Helper.GetMemberPath(inPrm as MemberExpression);
if (path.Any() && GetIncludePath(path) == null)
{
return(Expression.Default(outType));
}
}
var mapDefinition = _mapConfiguration.GetMapDefinition(inType, outType);
var projector = mapDefinition.Projector;
var oldInPrm = projector.Parameters[0];
var memberInit = (MemberInitExpression)projector.Body;
var replaceParams = new Dictionary <ParameterExpression, Expression> {
{ oldInPrm, inPrm }
};
var parameterReplaceVisitor = new ParameterReplaceVisitor(replaceParams);
return(base.Visit(parameterReplaceVisitor.Visit(memberInit)));
}
else if (node.Method.DeclaringType == typeof(MapContext) && node.Method.Name == "MapToList")
{
var retType = node.Method.ReturnType;
var inPrm = node.Arguments[0];
var genPrms = node.Method.GetGenericArguments();
var inType = genPrms[0];
var outType = genPrms[1];
IncludePath memberIncludePath = null;
if (_includes != null)
{
memberIncludePath = GetIncludePath(Helper.GetMemberPath(inPrm as MemberExpression));
if (memberIncludePath == null)
{
return(Expression.Default(retType));
}
}
var mapDefinition = _mapConfiguration.GetMapDefinition(inType, outType);
var subValue = new ProjectionVisitor(_mapConfiguration, memberIncludePath?.Children).VisitProjector(mapDefinition.Projector);
var subProjector = Expression.Call(typeof(Enumerable), "Select", new Type[] {
node.Method.GetGenericArguments()[0],
node.Method.GetGenericArguments()[1]
}, node.Arguments[0], subValue);
return(Expression.Call(typeof(Enumerable), "ToList", new Type[] { node.Method.ReturnType.GetGenericArguments()[0] }, subProjector));
}
else if (node.Method.DeclaringType == typeof(Enumerable) && node.Method.Name == "ToList")
{
var retType = node.Method.ReturnType;
var subNode = node.Arguments[0] as MethodCallExpression;
if (subNode != null && subNode.Method.DeclaringType == typeof(Enumerable) && subNode.Method.Name == "Select")
{
var inPrm = subNode.Arguments[0];
IncludePath memberIncludePath = null;
if (_includes != null)
{
memberIncludePath = GetIncludePath(Helper.GetMemberPath(inPrm as MemberExpression));
if (memberIncludePath == null)
{
return(Expression.Default(retType));
}
}
var subValue = new ProjectionVisitor(_mapConfiguration, memberIncludePath?.Children).Visit(subNode.Arguments[1]);
var subProjector = Expression.Call(typeof(Enumerable), "Select", new Type[] {
subNode.Method.GetGenericArguments()[0],
subNode.Method.GetGenericArguments()[1]
}, subNode.Arguments[0], subValue);
return(Expression.Call(typeof(Enumerable), "ToList", new Type[] { node.Method.ReturnType.GetGenericArguments()[0] }, subProjector));
}
}
return(base.VisitMethodCall(node));
}
private Expression VisitMapContextCall(MethodCallExpression node)
{
switch (node.Method.Name)
{
case "Map": {
var inPrm = node.Arguments[0];
var inType = inPrm.Type;
var outType = node.Method.ReturnType;
if (_includes != null && !CheckInclude(inPrm))
{
return(Expression.Default(outType));
}
var mapDefinition = _mapConfiguration.GetMapDefinition(inType, outType);
var projector = mapDefinition.Projector;
var oldInPrm = projector.Parameters[0];
var memberInit = (MemberInitExpression)projector.Body;
var replaceParams = new Dictionary <ParameterExpression, Expression> {
{ oldInPrm, inPrm }
};
var parameterReplaceVisitor = new ParameterReplaceVisitor(replaceParams);
return(Visit(parameterReplaceVisitor.Visit(memberInit)));
}
case "MapToList": {
var retType = node.Method.ReturnType;
var inPrm = node.Arguments[0];
var genPrms = node.Method.GetGenericArguments();
var inType = genPrms[0];
var outType = genPrms[1];
IncludePath memberIncludePath = null;
if (_includes != null && !TryGetIncludePath(inPrm, out memberIncludePath))
{
return(Expression.Default(retType));
}
var mapDefinition = _mapConfiguration.GetMapDefinition(inType, outType);
var subValue = new ProjectionVisitor(_mapConfiguration, memberIncludePath?.Children).VisitProjector(mapDefinition.Projector);
var methodName = node.Method.Name.Substring(3);
var subProjector = Expression.Call(typeof(Enumerable), "Select", new[] {
node.Method.GetGenericArguments()[0],
node.Method.GetGenericArguments()[1]
}, node.Arguments[0], subValue);
#if NET_STANDARD
var typeArg = node.Method.ReturnType.GenericTypeArguments[0];
#else
var typeArg = node.Method.ReturnType.GetGenericArguments()[0];
#endif
return(Expression.Call(typeof(Enumerable), methodName, new[] { typeArg }, subProjector));
}
default:
throw new InvalidOperationException(
$"Projection does not support MapContext method '{node.Method.Name}', only 'Map' and 'MapToList' are supported."
);
}
}