Project a name-value list into an object - c#

I want to be able to save an arbitrary flat object into the name-value list.
public class NameValueListEntity
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[InverseProperty(nameof(NameValueListContentEntity.Entity))]
public ICollection<NameValueListContentEntity> Content { get; set; }
}
public class NameValueListContent
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[ForeignKey("entity_fk")]
public NameValueListEntity Entity { get; set; }
public string Name { get; set; }
public string Value { get; set; }
}
public class ObjectToSave
{
public string Prop1 { get; set; }
public string Prop2 { get; set; }
}
I could use reflection to manually assemble/parse the list, but it will create a lot of overhead. Lots of NameValueListContent objects will be needlessly created both during the saving and the reading. Could it somehow be omitted? Especially during the reading, which is very performance-sensitive in my case.

Assume you have a AppDbContext class that holds your NameValueListContent class objects named as NVListContents. You can read and write the name-value list of objects by doing the following:
public class AppDbContext : DbContext
{
public DbSet<NameValueListContent> NVListContents { get; set; }
public AppDbContext()
: base()
{ }
}
public class SomeClass
{
private AppDbContext context { get; set; }
public SomeClass(AppDbContext _context)
{
context = _context;
}
public List<ObjectToSave> ReadObjects()
{
return context.NVListContents
.Select(nvlc => new ObjectToSave { Prop1 = nvlc.Name, Prop2 = nvlc.Value
}).ToList();
}
public bool WriteObjects(int id, string name, string value)
{
var query = context.NVListContents
.FirstOrDefault(nvlc => nvlc.Id == id);
if(query != null)
{
query.Name = name;
query.Value = value;
context.Update(query);
context.SaveChanges();
return true;
}
else
{
return false;
}
}
}
Hope, this answers to your question.

Related

How to elegantly map form flat object to complex list object using Automapper?

I have a flat complex type which I need to map to a complex type within a list. I have achieved it using the below code but it is not elegant. The mapping for each individual item has to be specified explicitly even though the types and names match. I wanted to know if there is a more elegant way of doing this without such verbosity and tight coupling?
using AutoMapper;
MapperConfiguration _config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<FlatObject, MyDTO>()
.ForMember(dst => dst.ListObject, opt => opt.MapFrom(src => new List<ListObject> {
new ListObject {
DTOCustObject = new DTOCustObject {
MyString = src.CustType.MyString,
MyInt = src.CustType.MyInt,
MyBool = src.CustType.MyBool,
//Others...
DTOMyObject = new DTOMyObject {
SomeString = src.CustType.MyObject.SomeString
//Others...
}
}
}
}));
});
_config.AssertConfigurationIsValid();
var flatObject = new FlatObject();
flatObject.CustType.MyString = "ABC123";
flatObject.CustType.MyInt = 12345;
flatObject.CustType.MyBool = true;
flatObject.CustType.MyObject.SomeString = "Some String Content";
IMapper mapper = new Mapper(_config);
var myDTO = mapper.Map<MyDTO>(flatObject);
Console.ReadKey();
//###############
//Entity - Source
//###############
public class FlatObject
{
public CustType CustType { get; set; } = new CustType();
}
public class CustType
{
public string? MyString { get; set; }
public int MyInt { get; set; }
public bool MyBool { get; set; }
public MyObject MyObject { get; set; } = new MyObject();
}
public class MyObject
{
public string? SomeString { get; set; }
}
//#################
//DTO - Destination
//#################
public class MyDTO
{
public List<ListObject> ListObject { get; set; } = new List<ListObject>();
}
public class ListObject
{
public DTOCustObject DTOCustObject { get; set; } = new DTOCustObject();
}
public class DTOCustObject
{
public string? MyString { get; set; }
public int MyInt { get; set; }
public bool MyBool { get; set; }
public DTOMyObject DTOMyObject { get; set; } = new DTOMyObject();
}
public class DTOMyObject
{
public string? SomeString { get; set; }
}
public class MyDTO
{
public List<DTOCustObject> DTOCustObjectList{ get; set; } = new List<DTOCustObject>();
}
public class DTOCustObject
{
public string? MyString { get; set; }
public int MyInt { get; set; }
public bool MyBool { get; set; }
public DTOMyObject DTOMyObject { get; set; } = new DTOMyObject();
public DTOCustObject(ICustObjectMapper mapper){
MyString = mapper.GetMyString();
MyInt = mapper.GetMyInt();
MyBool = mapper.GetMyBool();
DTOMyObject = mapper.GetDTOMyObject();
}
}
public class DTOMyObject
{
public string? SomeString { get; set; }
public DTOMyObject(IDTOmyObjectMapper mapper)
{
SomeString = mapper.GetSomeString();
}
}
Now simply implement the Interfaces and their GetMethods on the source object, in the corresponding classes. And presto. No need for any framework of any kind.
This means, no framework, will try change syntax, and force a rewrite. You aren't locked into keeping it updated, there won't be any dependencies on it, etc.
You are free, and the time it takes you to configure, and annotate the code, is equal to the amount of time it takes you to just write the damn interfaces and implementations.
If your objects are autogenerated, simply use the partial keyword, and make the interface implementations in a partial class. Problem solved.
Something to this effect:
public class CustType : ICustObjectMapper
{
public string? MyString { get; set; }
public int MyInt { get; set; }
public bool MyBool { get; set; }
public MyObject MyObject { get; set; } = new MyObject();
string GetMyString(){
return MyString;
}
// etc for the rest of the basic types.
DTOMyObject GetMyObject(){
return new DTOMyObject(MyObject)
}
}
public class MyObject : IDTOmyObjectMapper
{
public string? SomeString { get; set; }
public string GetSomeString()
{
return SomeString;
}
}
Of course, if you don't know how to declare an interface...
public interface ICustObjectMapper {
string GetMyString();
//etc.
}
Now please, for the love of everything on this planet. STOP USING MAPPING FRAMEWORKS IN C#, IT MAKES NO SENSE!

How to access a property in another class?

I am working with a WPF .Net Core 3 project.
In my UnbalancedViewModel I need to access an ID from another class (TestRunDto.cs).
UnbalancedViewModel
public class UnbalancedViewModel : ViewModelBase, IUnbalancedViewModel
{
private TestRunApi _testRunApi;
public UnbalancedViewModel(TestRunApi testRunApi, INotificationManager notifications)
{
_testRunApi = testRunApi;
}
private void StartTestRunJobExecuted(object obj)
{
_testRunApi.StartTestRun(1); ////I need the Id from TestRunDto (TestRunDto.Id)
}
}
TestRunApi
public async Task<TestRunLiveValueDto> GetTestRunLiveValue(int jobRunId)
{
await using var dbContext = new AldebaDbContext(_connectionString);
return await TestRunInteractor.GetTestRunLiveValue(jobRunId, dbContext);
}
public async Task StartTestRun(int testRunId)
{
await using var dbContext = new AldebaDbContext(_connectionString);
await TestRunInteractor.StartTestRun(dbContext, testRunId);
}
TestRunLiveValueDto
public class TestRunLiveValueDto
{
public TestRunDto TestRun { get; }
public bool ShowInstantaneousValue { get; set; }
public bool EnableStart { get; set; }
public bool EnableStop { get; set; }
public bool EnableMeasure { get; set; }
public int RecipeRpm { get; }
public string ActualRecipeName { get; }
public int DefaultSetOfPlaneId { get; }
public ICollection<BalancePlaneDto> ListBalancePlane { get; }
public ICollection<SetOfPlaneDto> ListSetOfPlane { get; }
public ICollection<SensorVibrationDto> SensorVibrations { get; set; }
public ICollection<EstimationDto> InstantaneousValues { get; set; }
public ICollection<EstimationDto> EstimationsValues { get; set; }
private TestRunLiveValueDto(TestRunDto testRun, bool enableStart, bool enableStop, int recipeRpm, ICollection<SensorVibrationDto> sensorVibrations)
{
EnableStart = enableStart;
EnableStop = enableStop;
TestRun = testRun;
RecipeRpm = recipeRpm;
SensorVibrations = sensorVibrations;
}
public static TestRunLiveValueDto Create(TestRunDto testRun, bool enableStart, bool enableStop, int recipeRpm, ICollection<SensorVibrationDto> sensorVibrations)
=> new TestRunLiveValueDto(testRun, enableStart, enableStop, recipeRpm, sensorVibrations);
}
TestRunDto
public class TestRunDto
{
public int Id { get; set; }
public int JobRunId { get; set; }
public string Name { get; set; }
public int TestRunNumber { get; set; }
public RunState State { get; set; }
public ICollection<BalancePlaneDto> BalancePlanes { get; set; } // Todo remove
private TestRunDto(int id, int jobRunId, RunState state, string name, int testRunNumber)
{
Id = id;
JobRunId = jobRunId;
Name = name;
TestRunNumber = testRunNumber;
State = state;
}
public static TestRunDto Create(int id, int jobRunId, RunState state, string name, int testRunNumber)
=> new TestRunDto(id, jobRunId, state, name, testRunNumber);
}
I have been trying to understand this, but I can not get a hold of the proper method to do this. Do I first declare a new TestRunDto class in my viewmodel or am I supposed to access it some other way?
You need to ensure class A has a reference to an instance of class B to access the properties, for example one way of doing this is to pass class A to B in a method where you can manipulate or access properties.
public class FooA
{
public string PropertyA { get; set; }
}
public class FooB
{
public string PropertyB { get; set; }
public void CanAccessFooA(FooA a)
{
a.PropertyA = "See, I can access this here";
}
}
Another is to pass class A to B in the constructor (known as dependency-injection)
public class FooB
{
FooA _a;
public FooB(FooA a)
{
// Pass instance of FooA to constructor
// (inject dependency) and store as a member variable
this._a = a;
}
public string PropertB { get; set; }
public void CanAccessFooA()
{
if (this._a != null)
this._a.PropertyA = "See, I can access this here";
}
}
Exactly how to structure your code is up to you, but the principle remains the same: Class B can only access Class A if it has a reference to an instance of it.
Look into 'Dependency Injection' as there are many techniques to achieve this.
Edit
One such technique might be abstracting the code to provide the ID to both, like so
public class IdProvider
{
public int Id { get; set; }
}
public class FooA
{
private int _id;
public FooA(IdProvider idProvider)
{
_id = idProvider.Id;
}
}
public class FooB
{
private int _id;
public FooB(IdProvider idProvider)
{
_id = idProvider.Id;
}
}
Now both classes have the same ID;
StartTestRun takes the tesRunId as it's parameter.
public async Task StartTestRun(int testRunId)
{
I think you need to call StartTestRunJobExecuted with this testRunId.
You will to change
private void StartTestRunJobExecuted(object obj)
to
private void StartTestRunJobExecuted(int testRunIdn)
{
_testRunApi.StartTestRun(testRunId); ////I need the Id from TestRunDto (TestRunDto.Id)
}
(This based on me guessing).

Map a flatten SQL response to an object containing lists of lists with Automapper

The error message that I'm receiving at runtime is:
Unmapped members were found. Review the types and members below.
Add a custom mapping expression, ignore, add a custom resolver, or modify the source/destination type
For no matching constructor, add a no-arg ctor, add optional arguments, or map all of the constructor parameters
List'1 -> MobileRoot (Destination member list)
System.Collections.Generic.List'1[[Strata.CS.Jazz.Biz.Dashboard.MobileInfo, Strata.CS.Jazz.Biz, Version=2019.10.0.0, Culture=neutral, PublicKeyToken=null]] -> Strata.Jazz.Web.Controllers.MobileController+MobileRoot (Destination member list)
Unmapped properties:
Users
From what I can tell from the error message is that AutoMapper needs to know how to handle the ForMember Users create in the MobileRoot, and then propagate that for each of the subsequent lists down the chain. Can anyone tell me how to do this efficiently using AutoMapper? I know how to do this with Linq using GroupBy and Select, so it is my thought that this should be do-able with AutoMapper.
The query I have returns this class:
public class MobileInfo
{
public string NameFull { get; set; }
public string EmailAddress { get; set; }
public string SolutionName { get; set; }
public int SortOrder { get; set; }
public string Name { get; set; }
public bool IsLegacy { get; set; }
public string Description { get; set; }
public string WidgetName { get; set; }
public int Row { get; set; }
public int Col { get; set; }
public int Height { get; set; }
public int Width { get; set; }
public string WidgetClassName { get; set; }
public string Data { get; set; }
}
I would like to use Automapper with profiles to have it return this:
internal class MobileRoot
{
public IEnumerable<MobileUser> Users { get; set; }
}
internal class MobileUser
{
public string NameFull { get; set; }
public string EmailAddress { get; set; }
public IEnumerable<MobileSolution> Solutions { get; set; }
}
internal class MobileSolution
{
public string Solution { get; set; } // MobileInfo.SolutionName
public int SortOrder { get; set; }
public IEnumerable<MobileDashboard> Dashboards { get; set; }
}
internal class MobileDashboard
{
public string Dashboard { get; set; } // MobileInfo.Name
public bool IsLegacy { get; set; }
public string Description { get; set; }
public IEnumerable<MobileWidget> Widgets { get; set; }
}
internal class MobileWidget
{
public string Widget { get; set; } // MobileInfo.WidgetName
public int Row { get; set; }
public int Col { get; set; }
public int Height { get; set; }
public int Width { get; set; }
public string WidgetClassName { get; set; }
public string Data { get; set; }
}
The Profiles I have defined so far are:
public class ProfileMobileRoot : Profile
{
public ProfileMobileRoot()
{
CreateMap<MobileInfo, MobileRoot>();
}
}
public class ProfileMobileUser : Profile
{
public ProfileMobileUser()
{
CreateMap<MobileInfo, MobileUser>();
}
}
public class ProfileMobileSolution : Profile
{
public ProfileMobileSolution()
{
CreateMap<MobileInfo, MobileSolution>();
}
}
public class ProfileMobileDashboard : Profile
{
public ProfileMobileDashboard()
{
CreateMap<MobileInfo, MobileRoot>();
}
}
public class ProfileMobileWidget : Profile
{
public ProfileMobileWidget()
{
CreateMap<MobileInfo, MobileWidget>();
}
}
You can do something like below. It's a little late so my solution isn't so sophisticated... but it works ;)
public class ProfileMobileRoot : Profile
{
public ProfileMobileRoot()
{
CreateMap<MobileInfo, MobileWidget>()
.ForMember(x=>x.Name, opt=>opt.MapFrom(x=>x.WidgetName));
CreateMap<IEnumerable<MobileInfo>, IEnumerable<MobileDashboard>>()
.ConvertUsing<DashboardConverter>();
CreateMap<IEnumerable<MobileInfo>, IEnumerable<MobileSolution>>()
.ConvertUsing<SolutionConverter>();
CreateMap<IEnumerable<MobileInfo>, IEnumerable<MobileUser>>()
.ConvertUsing<UserConverter>();
CreateMap<IEnumerable<MobileInfo>, MobileRoot>()
.ForMember(x => x.Users, opt => opt.MapFrom(x => x.ToList()));
}
}
class UserConverter : ITypeConverter<IEnumerable<MobileInfo>, IEnumerable<MobileUser>>
{
public IEnumerable<MobileUser> Convert(IEnumerable<MobileInfo> source, IEnumerable<MobileUser> destination, ResolutionContext context)
{
var groups = source.GroupBy(x => new { x.NameFull, x.EmailAddress});
foreach (var v in groups)
{
yield return new MobileUser()
{
EmailAddress = v.Key.EmailAddress,
NameFull = v.Key.NameFull,
Solutions = context.Mapper.Map<IEnumerable<MobileSolution>>(source.Where(x =>
v.Key.NameFull == x.NameFull && v.Key.EmailAddress== x.EmailAddress)).ToList()
};
}
}
}
class SolutionConverter : ITypeConverter<IEnumerable<MobileInfo>, IEnumerable<MobileSolution>>
{
public IEnumerable<MobileSolution> Convert(IEnumerable<MobileInfo> source, IEnumerable<MobileSolution> destination, ResolutionContext context)
{
var groups = source.GroupBy(x => new { x.SolutionName, x.SortOrder});
foreach (var v in groups)
{
yield return new MobileSolution()
{
Solution = v.Key.SolutionName,
SortOrder = v.Key.SortOrder,
Dashboards= context.Mapper.Map<IEnumerable<MobileDashboard>>(source.Where(x =>
v.Key.SolutionName== x.SolutionName&& v.Key.SortOrder== x.SortOrder)).ToList()
};
}
}
}
class DashboardConverter : ITypeConverter<IEnumerable<MobileInfo>, IEnumerable<MobileDashboard>>
{
public IEnumerable<MobileDashboard> Convert(IEnumerable<MobileInfo> source, IEnumerable<MobileDashboard> destination, ResolutionContext context)
{
var groups = source.GroupBy(x => new {x.Name, x.IsLegacy, x.Description});
foreach (var v in groups)
{
yield return new MobileDashboard()
{
Dashboard = v.Key.Name,
Description = v.Key.Description,
IsLegacy = v.Key.IsLegacy,
Widgets = context.Mapper.Map<IEnumerable<MobileWidget>>(source.Where(x =>
v.Key.IsLegacy == x.IsLegacy && v.Key.Name == x.Name && v.Key.Description == x.Description))
};
}
}
}

How to cast an object into type of another variable in C#

I'm working on an entity framework project and I'm trying to form a generic structure for adding joins to my table.
class BrowseCONTACTS_BASE : MyBrowseFrm<CONTACTS_BASE>
{
public BrowseCONTACTS_BASE()
{
MyInitialize();
}
public void MyInitialize()
{
//Here I may have more joins
MyAddJoins<ORDERS>("CONTACTS_BASE", "CB_REFNO", "ORDERS", "OR_REFNO", "OR_REFNO");
}
}
On the parent class MyBrowseFrm
partial class MyBrowseFrm<TEntity>:Form where TEntity:class
{
}
I have the following:
MyAddJoins Function that I call from the child class above
protected void MyAddJoins<TTable>(string pParent, string pParentKey, string pChild, string pChildKey,
string pDisplayField) where TTable:class, new()
{
var a = new TTable();
var item = new MyJoins<dynamic>
{
Parent = pParent,
Child = pChild,
ParentKey = pParentKey,
ChildKey = pChildKey,
DisplayField = pDisplayField,
ChildTable = a
};
MyBdJoins.Add(item);
}
//A list to store Joins added from the child table
private List<MyJoins<dynamic>> MyBdJoins;
protected struct MyJoins<TTable> where TTable : class
{
public string Parent;
public string ParentKey;
public string Child;
public string ChildKey;
public string DisplayField;
public TTable ChildTable;
}
Ok this is the part where I'm stuck, The following code will run when I press the search button.
private void MyGenerateQuery()
{
//Here I cast my Context to CONTACTS_BASE
var loContext = (DbSet<TEntity>)Context.GetPropValue(boName);
foreach (var join in MyBdJoins)
{
loContext
.Join(
(DbSet<ORDERS>)Context.GetPropValue(join.Child),
par => par.GetPropValue(join.ParentKey),
chld => chld.GetPropValue(join.ChildKey),
(par, chld) => new { GetPropValue = chld.GetPropValue(join.DisplayField) }
);
}
myGridView1.DataSource = loContext.ToList();
}
The code above at the part where it is:
(DbSet<ORDERS>)Context.GetPropValue(join.Child)
Here what I want to do is:
(DbSet<TTable>)Context.GetPropValue(join.Child)
of course, the above code gives me an error.
Note: in my code TEntity is CONTACTS_BASE and TTable is ORDERS
so how do I cast this object to type TTable
where it is in MyJoins Structure
public TTable ChildTable;
EDIT:
public partial class ORDERS
{
public int OR_REFNO { get; set; }
public string OR_PROD_CODE { get; set; }
public Nullable<DateTime> OR_DATE { get; set; }
public Nullable<int> OR_M_REFNO { get; set; }
public virtual CONTACTS_BASE CONTACTS_BASE { get; set; }
public virtual ORDER_TYPES ORDER_TYPES { get; set; }
}
public partial class CONTACTS_BASE
{
[SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public CONTACTS_BASE()
{
this.ORDERS = new List<ORDERS>();
}
public int CB_REFNO { get; set; }
public string CB_NAME { get; set; }
public string CB_ID_NO { get; set; }
public string CB_AGE { get; set; }
public Nullable<decimal> CB_TEL_NO { get; set; }
public string CB_EMAIL { get; set; }
public Nullable<DateTime> CB_ENROLL_DATE { get; set; }
public Nullable<DateTime> CB_START_DATE { get; set; }
public Nullable<DateTime> CB_END_DATE { get; set; }
[SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual IList<ORDERS> ORDERS { get; set; }
}

Updating List<T> in DbContext

I have a Model like this
public class Challenge
{
public int ID { get; set; }
public string Name { get; set; }
public string Blurb { get; set; }
public int Points { get; set; }
public string Category { get; set; }
public string Flag { get; set; }
public List<string> SolvedBy { get; set; }
}
public class ChallengeDBContext : DbContext
{
public DbSet<Challenge> Challenges { get; set; }
}
and then Controller like this. But I cannot update the List "SolvedBy", the next time I step through with the debugger, the list is still empty.
[HttpPost]
public string Index(string flag = "", int id=0)
{
Challenge challenge = db.Challenges.Find(id);
if (flag == challenge.Flag)
{
var chall = db.Challenges.Find(id);
if (chall.SolvedBy == null)
{
chall.SolvedBy = new List<string>();
}
chall.SolvedBy.Add(User.Identity.Name);
db.Entry(chall).State = EntityState.Modified;
db.SaveChanges();
//congrats, you solved the puzzle
return "got it";
}
else
{
return "fail";
}
}
is there any way around it to make a list of strings kept in the database?
EF don't know how to store an array in database table so it just ignore it. You can create another table/entity or use XML/JSON to store the list. You can serialize the list before saving and deserialize it after loading from database
A List<T> in a model would normally map to a second table, but in your DbContext you only have a single table. Try adding a second table.
public class ChallengeDBContext : DbContext
{
public DbSet<Challenge> Challenges { get; set; }
public DbSet<Solution> Solutions {get; set;}
}
public class Challenge
{
public int ID { get; set; }
public string Name { get; set; }
public string Blurb { get; set; }
public int Points { get; set; }
public string Category { get; set; }
public string Flag { get; set; }
public List<Solution> SolvedBy { get; set; }
}
public class Solution
{
public int ID { get; set; }
public string Name { get; set; }
}
Then your controller can use code along the lines of...
var chall = db.Challenges.Find(id);
if (chall.SolvedBy == null)
{
chall.SolvedBy = new List<Solution>();
}
chall.SolvedBy.Add(new Solution {Name=User.Identity.Name});
None of the above has been tested and I may have made some mistakes there, but the general principle I want to illustrate is the fact that you need another table. The List<T> represents a JOIN in SQL.

Categories

Resources