Deep clone with expression. New trees and expression trees

Question

I have two generated interfaces IPerson and IAddress .

However, I have defined property interfaces that inherit from these base interfaces

Interfaces

 public interface IPerson_Name : IPerson { String Name{get;set;}} public interface IPerson_Addresses : IPerson { ICollection<IAddress> Addresses{ get; set; } IAddress NewAddress(); } public interface IAddress_Line1 : IAddress { String Line1 { get; set; } } 

Then I have two implementations of each of the basic interfaces

Implementation

 public class Person : IPerson { public String Name { get; set; } public ICollection<Address> Addresses { get; set; } } public class PersonPoco : IPerson_Name, IPerson_Addresses { public string Name { get; set; } public ICollection<IAddress> Addresses { get; set; } public IAddress NewAddress() { return new AddressPoco(); } } public class Address : IAddress { public String Line1 { get; set; } } public class AddressPoco : IAddress_Line1 { public String Line1 { get; set; } } 

I am trying to build expression trees for conversion between PersonPoco and Person, as well as any other IPerson

I am creating a CopyTo function as such.

Copy Extenstion

 public static class IPersonExt { public static IQueryable<TDest> CopyTo<TSrc,TDest>(this IQueryable<TSrc> persons) where TSrc : IPerson, new() where TDest: IPerson, new() { var innerLambda = (LambdaExpression)CopyTo(typeof (TSrc), typeof (TDest)); var copyExpr = Expression.Lambda<Func<TSrc, TDest>>(innerLambda.Body, innerLambda.Parameters); return persons.Select(copyExpr); } internal static LambdaExpression CopyTo(Type tSrc, Type tDest) { var dest = Activator.CreateInstance(tDest); var personparam = Expression.Parameter(tSrc); var destNewExpr = Expression.New(tDest); var memberbindings = new List<MemberBinding>(); IPerson_Name destName; IPerson_Name srcName; if ((tDest.IsInstanceOfType(typeof(IPerson_Name)) || tDest.IsInstanceOfType(typeof(Person))) && (tSrc.IsInstanceOfType(typeof(IPerson_Name)) || tSrc.IsInstanceOfType(typeof(Person)))) { memberbindings.Add(Expression.Bind(tDest.GetProperty("Name"), Expression.Property(personparam, "Name"))); } var toEntityParameterExpression = Expression.MemberInit(destNewExpr, memberbindings); return Expression.Lambda( toEntityParameterExpression, personparam ); } } 

My intention is to save compiled output for each implementation to implement IPerson and IAddress conversions.

If you want to know more about my intentions, see this question.

Edit

I got a basic setting for copying to the new version. It still works for basic properties. I updated the code above

Answer 1

EDIT: Apparently, linq for entities cannot understand the method calls in these expressions. therefore it will not help.

Here is the gist

An interface that implements the following interface will be able to copy the properties of its common interfaces.

 public interface IEntity { } public interface IEntityObject : IEntity { } public interface IEntityCollection : IEntity { } public interface IEntityProperty : IEntity { } 

Then for each property of the object you need to create an interface

 public interface IThing:IEntity{} public interface IThing_Property: IThing, IEntityProperty { int SimpleProperty{get;set;} } public interface IThing_ComplexProperty: IThing, IEntityObject{} public interface IThing_ComplexProperty<T> : IEntity_ComplexProperty where T:class, IEntity,new() { T SomeProperty{get;set;} } public interface IThing_CollectionProperty: IThing, IEntityCollection{} public interface IThing_CollectionProperty<T> :IEntity_CollectionProperty where T:class, IEntity,new() { IEnumerable<T> SomeCollectionProperty{get;set;} } 

Now if you do

 IQueryable<SomeThingImpl> x; IQueryable<SomeOtherThingImpl> y = x.CopyTo<SomeThingImpl,SomeOtherThingImpl>() 

I will not be called before listing.

In addition, if generics types share any IEntity interfaces, they will also be copied.

For a more complete implementation, here is a different meaning

Here the classes look like

 public static class CopyToExt { private static readonly ConcurrentDictionary<Type, LambdaExpression> expressions; private static readonly ConcurrentDictionary<Type, Object> funcs; private static readonly ConcurrentDictionary<Type, LambdaExpression> mergeStackExpr; private static ConcurrentDictionary<Type, Object> mergeStackFunc; public static MethodInfo AsQueryableMethod; public static MethodInfo SelectMethod; public static MethodInfo ToListMethod; public static MethodInfo CopyToMethod; public static MethodInfo AddMergeMethod; public static MethodInfo CreateMergeMethod; public static MethodInfo TryCopyMethod; static CopyToExt() { mergeStackExpr = new ConcurrentDictionary<Type, LambdaExpression>(new Dictionary<Type, LambdaExpression>()); foreach (MethodInfo m in typeof(Queryable).GetMethods().Where(m => m.Name == "Select")) foreach (ParameterInfo p in m.GetParameters().Where(p => p.Name.Equals("selector"))) if (p.ParameterType.GetGenericArguments().Any(x => x.GetGenericArguments().Count() == 2)) SelectMethod = (MethodInfo)p.Member; foreach (MethodInfo m in typeof(Enumerable).GetMethods().Where(m => m.Name == "ToList")) foreach (ParameterInfo p in m.GetParameters().Where(p => p.Name.Equals("source"))) if (p.ParameterType.GetGenericArguments().Count() == 1) ToListMethod = (MethodInfo)p.Member; foreach (MethodInfo m in typeof(Queryable).GetMethods().Where(m => m.Name == "AsQueryable")) foreach (ParameterInfo p in m.GetParameters().Where(p => p.Name.Equals("source"))) if (p.ParameterType.GetGenericArguments().Count() == 1) AsQueryableMethod = (MethodInfo)p.Member; CreateMergeMethod = typeof(CopyToExt).GetMethods().First(m => m.Name == "CreateMergeStack"); AddMergeMethod = typeof(MergeStack).GetMethods().First(m => m.Name == "AddReturnOrCreateAddReturn"); TryCopyMethod = typeof(MergeStack).GetMethods().First(m => m.Name == "TryCopy"); } public static IQueryable<TDest> CopyTo<TSrc, TDest>(this IQueryable<TSrc> queryable) where TSrc : class, IEntity where TDest : class, IEntity { var copyExpr = CreateTryCopy<TSrc, TDest>(); var ms = CreateMergeStack<TSrc>(); return queryable.Select(ms).Select(copyExpr); } public static IEnumerable<TDest> CopyTo<TSrc, TDest>(this IEnumerable<TSrc> queryable) where TSrc : class, IEntity where TDest : class, IEntity { return queryable.AsQueryable().CopyTo<TSrc, TDest>().AsEnumerable(); } public static Expression<Func<TSrc, Stackholder<TSrc>>> CreateMergeStack<TSrc>() { return mergeStackExpr.GetOrAdd(typeof(TSrc), (type) => { var shtype = typeof(Stackholder<TSrc>); var parm = Expression.Parameter(typeof(TSrc)); var destNewExpr = Expression.New(shtype); var methodcall = Expression.Call(null, CopyToExt.AddMergeMethod); var memInit = Expression.MemberInit(destNewExpr, Expression.Bind(shtype.GetField("Src"), parm), Expression.Bind(shtype.GetField("Ms"), methodcall)); return Expression.Lambda<Func<TSrc, Stackholder<TSrc>>>(memInit, parm); }) as Expression<Func<TSrc, Stackholder<TSrc>>>; } public static Expression<Func<Stackholder<TSrc>, TDest>> CreateTryCopy<TSrc, TDest>() { var shtype = typeof(Stackholder<TSrc>); var parentParam = Expression.Parameter(shtype); var SrcExpr = Expression.PropertyOrField(parentParam, "Src"); var MSExpr = Expression.PropertyOrField(parentParam, "Ms"); var tcMethod = Expression.Call(MSExpr, TryCopyMethod.MakeGenericMethod(new Type[] { typeof(TSrc), typeof(TDest) }), SrcExpr); return Expression.Lambda<Func<Stackholder<TSrc>, TDest>>(tcMethod, parentParam); } internal static bool Impliments(this Type type, Type inheritedType) { return (type.IsSubclassOf(inheritedType) || type.GetInterface(inheritedType.FullName) != null); } internal static bool Impliments<T>(this Type type, Type inheritedType = null) { return type.Impliments(typeof(T)); } private static ConcurrentDictionary<Type, Object> AssignDict = new ConcurrentDictionary<Type, Object>(new Dictionary<Type, Object>()); internal static Func<TSrc, TDest, MergeStack, TDest> Assign<TSrc, TDest>() { return (Func<TSrc, TDest, MergeStack, TDest>) AssignDict.GetOrAdd(typeof (Func<TSrc, TDest>), (indexType) => { var tSrc = typeof (TSrc); var tDest = typeof (TDest); var srcEntityInterfaces = tSrc.GetInterfaces().Where(x => x.Impliments<IEntity>()); var destEntityInterfaces = tDest.GetInterfaces().Where(x => x.Impliments<IEntity>()); var srcParam = Expression.Parameter(tSrc); var destParam = Expression.Parameter(tDest); var MSExpr = Expression.Parameter(typeof (MergeStack)); var common = destEntityInterfaces.Intersect(srcEntityInterfaces); var memberbindings = common.Where(x => x.Impliments<IEntityProperty>()) .Select(type => type.GetProperties().First()) .Select( prop => Expression.Assign(Expression.Property(destParam, prop.Name), Expression.Property(srcParam, prop.Name))) .Cast<Expression>().ToList(); foreach (var type in common.Where(x => x.Impliments<IEntityObject>())) { var destSubType = destEntityInterfaces.First(x => x.Impliments(type)) .GetGenericArguments() .First(); var srcSubType = srcEntityInterfaces.First(x => x.Impliments(type)) .GetGenericArguments() .First(); var dProp = destEntityInterfaces.First(x => x.Impliments(type)).GetProperties().First(); var sProp = srcEntityInterfaces.First(x => x.Impliments(type)).GetProperties().First(); var tcParam = Expression.Parameter(srcSubType); var tcMethod = Expression.Call(MSExpr, TryCopyMethod.MakeGenericMethod(new Type[] {srcSubType, destSubType}), tcParam); LambdaExpression mergeLambda = Expression.Lambda(tcMethod, tcParam); MemberExpression memberExpression = Expression.Property(srcParam, sProp.Name); InvocationExpression invocationExpression = Expression.Invoke(mergeLambda, Expression.Property(srcParam, sProp.Name)); var check = Expression.Condition( Expression.MakeBinary(ExpressionType.NotEqual, memberExpression, Expression.Constant(null, sProp.PropertyType)), invocationExpression, Expression.Constant(null, invocationExpression.Type)); BinaryExpression binaryExpression = Expression.Assign(Expression.Property(destParam, dProp.Name), check); memberbindings.Add(binaryExpression); } foreach (var type in common.Where(x => x.Impliments<IEntityCollection>())) { var destSubType = destEntityInterfaces.First(x => x.Impliments(type)) .GetGenericArguments() .First(); var srcSubType = srcEntityInterfaces.First(x => x.Impliments(type)) .GetGenericArguments() .First(); var dProp = destEntityInterfaces.First(x => x.Impliments(type)).GetProperties().First(); var sProp = srcEntityInterfaces.First(x => x.Impliments(type)).GetProperties().First(); var tcParam = Expression.Parameter(srcSubType); var tcMethod = Expression.Call(MSExpr, TryCopyMethod.MakeGenericMethod(new Type[] {srcSubType, destSubType}), tcParam); LambdaExpression mergeLambda = Expression.Lambda(tcMethod, tcParam); var memberExpression = Expression.Property(srcParam, sProp.Name); var selectExpr = Expression.Call(null, AsQueryableMethod.MakeGenericMethod(new Type[] {srcSubType}), new Expression[] {memberExpression}); selectExpr = Expression.Call(null, CopyToExt.SelectMethod.MakeGenericMethod(new Type[] {srcSubType, destSubType}), new Expression[] {selectExpr, mergeLambda}); selectExpr = Expression.Call(null, CopyToExt.ToListMethod.MakeGenericMethod(new Type[] {destSubType}), new Expression[] {selectExpr}); var check = Expression.Condition( Expression.MakeBinary(ExpressionType.NotEqual, memberExpression, Expression.Constant(null, sProp.PropertyType)), selectExpr, Expression.Constant(null, selectExpr.Type)); memberbindings.Add(Expression.Assign(Expression.Property(destParam, dProp.Name), check)); } memberbindings.Add(destParam); return Expression.Lambda<Func<TSrc, TDest, MergeStack, TDest>>(Expression.Block(memberbindings), new ParameterExpression[] {srcParam, destParam, MSExpr}).Compile(); }); } } public class Stackholder<TSrc> { public MergeStack Ms; public TSrc Src; } public class MergeStack { private static ConcurrentDictionary<Thread, MergeStack> StackDict = new ConcurrentDictionary<Thread, MergeStack>(new Dictionary<Thread, MergeStack>()); private readonly Dictionary<Type, Dictionary<Object, Object>> _mergeObjDict = new Dictionary<Type, Dictionary<object, object>>(); public static MergeStack AddReturnOrCreateAddReturn() { return StackDict.GetOrAdd(Thread.CurrentThread, (x) => new MergeStack() { }); } public TDest TryCopy<TSrc, TDest>(TSrc Src) where TSrc : class, IEntity where TDest : class, IEntity, new() { if (Src == null) return null; var objToIndex = new TDest(); Dictionary<object, object> objToObj; if (!_mergeObjDict.ContainsKey(objToIndex.GetType())) { objToObj = new Dictionary<object, object>(); _mergeObjDict.Add(objToIndex.GetType(), objToObj); } else { objToObj = _mergeObjDict[objToIndex.GetType()]; } if (!objToObj.ContainsKey(Src)) { objToObj.Add(Src, objToIndex); return CopyToExt.Assign<TSrc, TDest>()(Src, objToIndex, this); } return objToObj[Src] as TDest; } } 

Here is a text template file for creating the specified classes from an EF chart