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);
return(Expression.Call(typeof(Enumerable), methodName, new[] { node.Method.ReturnType.GetGenericArguments()[0] }, subProjector));
}
default:
throw new InvalidOperationException(
$"Projection does not support MapContext method '{node.Method.Name}', only 'Map' and 'MapToList' are supported."
);
}
}
private IncludePath GetIncludePath(IEnumerable <string> path)
{
IncludePath include = null;
var includes = _includes;
foreach (var member in path)
{
include = includes.FirstOrDefault(i => i.Member == member);
if (include == null)
{
return(null);
}
includes = include.Children;
}
return(include);
}
private bool TryGetIncludePath(Expression memberExp, out IncludePath includePath)
{
includePath = null;
var path = Helper.GetMemberPath(memberExp);
var includes = _includes;
foreach (var member in path)
{
includePath = includes.FirstOrDefault(i => i.Member == member);
if (includePath == null)
{
return(false);
}
includes = includePath.Children;
}
return(true);
}
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));
}
