Automapper map child object based on parent value - c#

If the header object has a prop set to 1 then it should map field type1 in the child to type in the destination. Otherwise it should use type2.
Bonus points if I can use IValueResolver to use type1 or type1extended if extended is filled.
Here is my minimum viable product/demo
using AutoMapper;
using AutoMapper.Configuration.Conventions;
using System;
using System.Collections.Generic;
namespace ConsoleAppAutoMapper
{
class Program
{
static void Main(string[] args)
{
var source = new SourceParent() {
Header = new SourceHeader() { Currency = 30, FileName = "testfile.txt", Type = 1 },
Rows = new List<SourceRow>() {
new SourceRow() { ID = 1, Amount1 = 100, Amount2 = 200 },
new SourceRow() { ID = 2, Amount1 = 101, Amount2 = 201 },
new SourceRow() { ID = 3, Amount1 = 102, Amount2 = 202 }
} };
var config = new MapperConfiguration(cfg => {
cfg.CreateMap<SourceParent, DestinationParent>();
cfg.CreateMap<SourceRow, DestinationRow>()
.ForMember(x => x.Type, opt => opt.MapFrom(p => p.Type1));
});
var mapper = config.CreateMapper();
var dest = mapper.Map<DestinationParent>(source);
Console.WriteLine(dest.Rows[0].Type == 100); // should be true if SourceHeader.Type = 1 and should be 200 (SourceRow.Type2) if SourceHeader.Type = 2
Console.ReadKey();
}
}
// source
public class SourceParent
{
public SourceHeader Header { get; set; }
public List<SourceRow> Rows { get; set; }
}
public class SourceHeader
{
public string FileName { get; set; }
public int Type { get; set; }
}
public class SourceRow
{
public int ID { get; set; }
public int Amount1 { get; set; }
public int Amount2 { get; set; }
}
//destination
public class DestinationParent
{
public DestinationHeader Header { get; set; }
public List<DestinationRow> Rows { get; set; }
}
public class DestinationHeader
{
public string FileName { get; set; }
}
public class DestinationRow
{
public int ID { get; set; }
public int Type { get; set; }
public int Amount{ get; set; } // if type=1 then source is amount1 otherwise amount2
}
}
edit
I tried to solve it by having an Aftermap on the sourceparent mapping which took the value from the header and put it in a prop from the destinationrow (it is the Type value) and wanted another aftermap on the row to see if I needed prop A or B (type1 or type2) but that aftermap still does not know (it's null) what type it is because it happens before the aftermap of the parent it seems.
public class MapRowType : IMappingAction<SourceParent, DestinationParent>
{
public void Process(SourceParentsource, DestinationParent destination)
{
foreach (var row in destination.Rows)
{
row.Type = source.Header.Type; // so now I have type in the row, but still do not know if I should use Amount1 or Amount2
}
}
}

you can use the resolution context. Declare the mapping:
cfg.CreateMap<SourceRow, DestinationRow>()
.ForMember(x => x.Type,
opt => opt.ResolveUsing((src, dest1, destMember, resContext) => resContext.Items["Type"] as int? == 1? src.Type2: src.Type1));
After pass the value:
var dest = mapper.Map<DestinationParent>(source, opts=> { opts.Items["Type"] = source.Header.Type;});

Related

Automapper Serialize/Deserialize source string to list using resolver

I am trying to map source string to List<T> for member but the value of the mapped member list property is always null.
Here is my code.
//Source model
public class Claims
{
public int Id { get; set; }
public string ClaimType {get; set; }
public string ClaimValue { get; set; } // produce json string [{"Action":"read","Status":"active"}]
}
// Dest model
public class ClaimsDto
{
public int Id { get; set; }
public string ClaimType { get; set; }
public List<ResourceActions> ClaimValues { get; set; }
}
public class ResourceActions
{
public string Action { get; set; }
public string Status { get; set; }
}
CreateMap<ResourceActions, ResourceActions>();
CreateMap<Claims, ClaimsDto>()
.ForMember(dest => dest.ClaimValues,
opt => opt.MapFrom( src=> JsonConvert.DeserializeObject<List<ResourceActions>>(src.ClaimValue)))
.ReverseMap();
Also tried with resolver like this.
.ForMember(dto => dto.ClaimValues, opt => opt.ResolveUsing<CustomResolver,string>(src=>src.ClaimValue ))
The resolver:
public class CustomResolver : IMemberValueResolver<Claims, ClaimsDto, string, List<ResourceActions>>
{
public List<ResourceActions> Resolve(Claims source, ClaimsDto destination, string sourceMember, List<ResourceActions> destinationMember, ResolutionContext context)
{
var data = JsonConvert.DeserializeObject<List<ResourceActions>>(sourceMember);
return context.Mapper.Map<List<ResourceActions>>(data); // not working
return JsonConvert.DeserializeObject<List<ResourceActions>>(sourceMember); // not working
}
}
And the controller
var mapped = _mapper.Map<List<ClaimsDto>>(source); // success without exception but the list property is null.
Other properties are mapped except this string to List<T> property.
I think this profile should solve the issue:
public class MyMapperProfile : Profile
{
public MyMapperProfile()
{
CreateMap<Claims, ClaimsDto>()
.ForMember(dto => dto.ClaimValues, cfg => cfg.MapFrom((claim, _) =>
JsonSerializer.Deserialize<IReadOnlyCollection<ResourceActions>>(claim.ClaimValue)));
}
}
Here is an example:
var config = new MapperConfiguration(cfg => cfg.AddProfile<MyMapperProfile>());
var mapper = config.CreateMapper();
var someClaims = new List<Claims>
{
new Claims { Id = 5, ClaimType = "Foo", ClaimValue = #"[{""Action"":""read"",""Status"":""active""}]" },
new Claims { Id = 7, ClaimType = "Bar", ClaimValue = #"[{""Action"":""create"",""Status"":""disabled""}]" },
};
var result = mapper.Map<List<ClaimsDto>>(someClaims);
foreach (var item in result)
{
Console.WriteLine(JsonSerializer.Serialize(item));
}

How to do Cascading Include in LiteDB

here is example on how to store cross-referenced entities in LiteDB. LiteDB stores the cross-referenced entities perfectly fine, but problem comes when I am trying to find/load entities back. My goal is NOT ONLY the requested entity but also referenced ones. There is quick tutorial section "DbRef for cross references" on LiteDB webpage how one can realize it. LiteDB has "Include" option (which is called before "FindAll") which says which referenced entities must be loaded as well. I am trying to achieve it in this code example but with no results, i.e, the code raises Exception("D_Ref") meaning "D_Ref" reference is not loaded:
namespace _01_simple {
using System;
using LiteDB;
public class A {
public int Id { set; get; }
public string Name { set; get; }
public B B_Ref { set; get; }
}
public class B {
public int Id { set; get; }
public string Name { set; get; }
public C C_Ref { set; get; }
}
public class C {
public int Id { set; get; }
public string Name { set; get; }
public D D_Ref { set; get; }
}
public class D {
public int Id { set; get; }
public string Name { set; get; }
}
class Program {
static void Main(string[] args) {
test_01();
}
static string NameInDb<T>() {
var name = typeof(T).Name + "s";
return name;
}
static void test_01() {
if (System.IO.File.Exists(#"MyData.db"))
System.IO.File.Delete(#"MyData.db");
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var Bs = db.GetCollection<B>(NameInDb<B>());
var Cs = db.GetCollection<C>(NameInDb<C>());
var Ds = db.GetCollection<D>(NameInDb<D>());
LiteDB.BsonMapper.Global.Entity<A>().DbRef(x => x.B_Ref, NameInDb<B>());
LiteDB.BsonMapper.Global.Entity<B>().DbRef(x => x.C_Ref, NameInDb<C>());
LiteDB.BsonMapper.Global.Entity<C>().DbRef(x => x.D_Ref, NameInDb<D>());
var d = new D { Name = "I am D." };
var c = new C { Name = "I am C.", D_Ref = d };
var b = new B { Name = "I am B.", C_Ref = c };
var a = new A { Name = "I am A.", B_Ref = b };
Ds.Insert(d);
Cs.Insert(c);
Bs.Insert(b);
As.Insert(a);
}
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var all_a = As
.Include(x => x.B_Ref)
.FindAll();
foreach (var a in all_a) {
if (a.B_Ref == null)
throw new Exception("B_Ref");
if (a.B_Ref.C_Ref == null)
throw new Exception("C_Ref");
if (a.B_Ref.C_Ref.D_Ref == null)
throw new Exception("D_Ref");
}
}
}
}}
after small research I've resolved the issue simply by adding extra "Include" parameterize by "x => x.B_Ref.C_Ref" lambda where x.B_Ref.C_Ref is a path in hierarchy of references:
var all_a = As
.Include(x => x.B_Ref)
.Include(x => x.B_Ref.C_Ref)
.FindAll();
Here is complete example
namespace _01_simple {
using System;
using LiteDB;
public class A {
public int Id { set; get; }
public string Name { set; get; }
public B B_Ref { set; get; }
}
public class B {
public int Id { set; get; }
public string Name { set; get; }
public C C_Ref { set; get; }
}
public class C {
public int Id { set; get; }
public string Name { set; get; }
public D D_Ref { set; get; }
}
public class D {
public int Id { set; get; }
public string Name { set; get; }
}
class Program {
static void Main(string[] args) {
test_01();
}
static string NameInDb<T>() {
var name = typeof(T).Name + "s";
return name;
}
static void test_01() {
if (System.IO.File.Exists(#"MyData.db"))
System.IO.File.Delete(#"MyData.db");
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var Bs = db.GetCollection<B>(NameInDb<B>());
var Cs = db.GetCollection<C>(NameInDb<C>());
var Ds = db.GetCollection<D>(NameInDb<D>());
LiteDB.BsonMapper.Global.Entity<A>().DbRef(x => x.B_Ref, NameInDb<B>());
LiteDB.BsonMapper.Global.Entity<B>().DbRef(x => x.C_Ref, NameInDb<C>());
LiteDB.BsonMapper.Global.Entity<C>().DbRef(x => x.D_Ref, NameInDb<D>());
var d = new D { Name = "I am D." };
var c = new C { Name = "I am C.", D_Ref = d };
var b = new B { Name = "I am B.", C_Ref = c };
var a = new A { Name = "I am A.", B_Ref = b };
Ds.Insert(d);
Cs.Insert(c);
Bs.Insert(b);
As.Insert(a);
}
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var all_a = As
.Include(x => x.B_Ref)
.Include(x => x.B_Ref.C_Ref)
.Include(x => x.B_Ref.C_Ref.D_Ref)
.FindAll();
foreach (var a in all_a) {
if (a.B_Ref == null)
throw new Exception("B_Ref");
if (a.B_Ref.C_Ref == null)
throw new Exception("C_Ref");
if (a.B_Ref.C_Ref.D_Ref == null)
throw new Exception("D_Ref");
}
}
}
}}
I hope it saves someone's time.
Update: LiteDB author says there is no support for Cascading Include. But it is planned in the next version (see issue). Consider, once, let say, B_Ref is a Lite of B, then there is no mechanism to force deeper Include.

LINQ to SQL select property name by string on projection

How can I achieve the projection on the last select? I need the property defined by the string prop.Name to be selected into the SeriesProjection object.
public override IQueryable<SeriesProjection> FilterOn(string column)
{
//Get metadata class property by defined Attributes and parameter column
var prop = typeof(CommunicationMetaData)
.GetProperties()
.Single(p => p.GetCustomAttribute<FilterableAttribute>().ReferenceProperty == column);
var attr = ((FilterableAttribute)prop.GetCustomAttribute(typeof(FilterableAttribute)));
var param = Expression.Parameter(typeof(Communication));
Expression conversion = Expression.Convert(Expression.Property(param, attr.ReferenceProperty), typeof(int));
var condition = Expression.Lambda<Func<Communication, int>>(conversion, param); // for LINQ to SQl/Entities skip Compile() call
var result = DbQuery.Include(prop.Name)
//.GroupBy(c => c.GetType().GetProperty(attr.ReferenceProperty))
.GroupBy(condition)
.OrderByDescending(g => g.Count())
.Select(group => new SeriesProjection()
{
Count = group.Count(),
Id = group.Key,
//set this navigation property dynamically
Name = group.FirstOrDefault().GetType().GetProperty(prop.Name)
});
return result;
}
For the GroupBy I used the fk property name that's always an int on the Communication entity, but for the select I can't figure out the expression.
[EDIT]
System.Data.Entity.Infrastructure.DbQuery<Communication> DbQuery;
---
[MetadataType(typeof(CommunicationMetaData))]
public partial class Communication
{
public int CommunicationId { get; set; }
public Nullable<int> TopicId { get; set; }
public int CreateById { get; set; }
public virtual Employee CreateByEmployee { get; set; }
public virtual Topic Topic { get; set; }
}
---
public class CommunicationMetaData
{
[Filterable("By Employee", nameof(Communication.CreateById))]
public Employee CreateByEmployee { get; set; }
[Filterable("By Topic", nameof(Communication.TopicId))]
public Topic Topic { get; set; }
}
---
[AttributeUsage(AttributeTargets.Property)]
public class FilterableAttribute : System.Attribute
{
public FilterableAttribute(string friendlyName, string referenceProperty)
{
FriendlyName = friendlyName;
ReferenceProperty = referenceProperty;
}
public string FriendlyName { get; set; }
public string ReferenceProperty { get; set; }
}
---
public class SeriesProjection
{
public int Count { get; set; }
public int Id { get; set; }
public object Name { get; set; }
}
Without some expression helper library, you have to build the whole selector expression manually.
The input of the selector will be a parameter of type IGrouping<int, Communication>, the result type - SeriesProjection, and the body will be MemberInit expression:
var projectionParameter = Expression.Parameter(typeof(IGrouping<int, Communication>), "group");
var projectionType = typeof(SeriesProjection);
var projectionBody = Expression.MemberInit(
// new SeriesProjection
Expression.New(projectionType),
// {
// Count = group.Count(),
Expression.Bind(
projectionType.GetProperty(nameof(SeriesProjection.Count)),
Expression.Call(typeof(Enumerable), "Count", new[] { typeof(Communication) }, projectionParameter)),
// Id = group.Key
Expression.Bind(
projectionType.GetProperty(nameof(SeriesProjection.Id)),
Expression.Property(projectionParameter, "Key")),
// Name = group.FirstOrDefault().Property
Expression.Bind(
projectionType.GetProperty(nameof(SeriesProjection.Name)),
Expression.Property(
Expression.Call(typeof(Enumerable), "FirstOrDefault", new[] { typeof(Communication) }, projectionParameter),
prop.Name))
// }
);
var projectionSelector = Expression.Lambda<Func<IGrouping<int, Communication>, SeriesProjection>>(projectionBody, projectionParameter);
and then of course use simply:
var result = DbQuery.Include(prop.Name)
.GroupBy(condition)
.OrderByDescending(g => g.Count())
.Select(projectionSelector);

How to use LINQ to assign while selecting to new object

I have a data contract called GameImage and GameTone. I am trying to join the two entities, and assign a unique random position between 0-11 to an Image/Tone association. I am able to join the tables but am unsure if there is a way to assign the position while creating the object in a LINQ lambda expression.
// Need random positions from 0-11 to to be associated to an image/tone
var positions = Enumerable.Range(0, 11).Shuffle().ToList();
// Associate image/tones
imageToneData = game.GameImages.Shuffle()
.Join(game.GameTones, gi => gi.GameId, gt => gt.GameId, (gi, gt) => new ImageToneData
{
Image = new ImageData()
{
ImageFileName = gi.Image.ImageFileName,
ImageId = gi.ImageId
},
Tone = new ToneData()
{
ToneFileName = gt.Tone.ToneFileName,
ToneId = gt.ToneId
},
Position = // What goes here?
});
These are my data contracts
[DataContract]
public class ImageToneData
{
[DataMember]
public ImageData Image { get; set; }
[DataMember]
public ToneData Tone { get; set; }
[DataMember]
public int Position { get; set; }
}
[DataContract]
public class ImageData
{
[DataMember]
public int ImageId { get; set; }
[DataMember]
public string ImageFileName { get; set; }
}
}
[DataContract]
public class ToneData
{
[DataMember]
public int ToneId { get; set; }
[DataMember]
public string ToneFileName { get; set; }
}
var positions = Enumerable.Range(0, 11).OrderBy(a => Guid.NewGuid()).ToList();
// Associate image/tones
imageToneData = game.GameImages.Shuffle()
.Join(game.GameTones, gi => gi.GameId, gt => gt.GameId, (gi, gt) => new ImageToneData
{
Image = new ImageData()
{
ImageFileName = gi.Image.ImageFileName,
ImageId = gi.ImageId
},
Tone = new ToneData()
{
ToneFileName = gt.Tone.ToneFileName,
ToneId = gt.ToneId
},
Position = positions.First()
});

Automapper ignores the ignore property for nested object

I have an Order object that has a list of OrderLine objects and an OrderVm object that has a list of OrderLineVm objects. The OrderLine object has a ValueB field that does not exist in the OrderLineVm object.
The problem I have is that ValueB gets set to null by AutoMapper even though I tell it to ignore this property:
[TestFixture]
public class AutomapperDestinationIssueTest2
{
[Test]
public void OrderLineValueBShouldNotBeNull()
{
Mapper.CreateMap<OrderVm, Order>().ForMember(dest => dest.Lines, opt => opt.UseDestinationValue());
Mapper.CreateMap<OrderLineVm, OrderLine>()
.ForMember(dest => dest.ValueB, opts => opts.Ignore());
var orderVm = new OrderVm() { Id = 1 };
orderVm.Lines.Add(new OrderLineVm() { ValueA = "New ValueA"} );
var order = new Order() { Id = 1 };
order.Lines.Add(new OrderLine() { ValueA = "Old ValueA", ValueB = "Old ValueB " });
Mapper.Map(orderVm, order);
Assert.IsNotNull(order.Lines[0].ValueB); // Fails. ValueB is null here.
}
public class OrderLine
{
public string ValueA { get; set; }
public string ValueB { get; set; }
}
public class OrderLineVm
{
public string ValueA { get; set; }
}
public class Order
{
public int Id { get; set; }
public List<OrderLine> Lines { get; set; }
public Order()
{
Lines = new List<OrderLine>();
}
}
public class OrderVm
{
public int Id { get; set; }
public List<OrderLineVm> Lines { get; set; }
public OrderVm()
{
Lines = new List<OrderLineVm>();
}
}
}
What I am missing?
Add an additional mapping to your map creation, the map from list to list and it starts working.
Mapper.CreateMap<OrderVm, Order> ().ForMember(dest => dest.Lines, opt => opt.UseDestinationValue());
Mapper.CreateMap<List<OrderLineVm>,List<OrderLine>> ();
Mapper.CreateMap<OrderLineVm, OrderLine> ().ForMember (d => d.ValueB, opt => opt.Ignore());

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