object-binder 1.0.1

object-binder

Nuget

Description

Given a type X (maybe an interface or class) and type Y (may to be an interface or class with virtual properties), this library will generate a type Z where it implements (or extend) Y and take an instance of X in the constructor where for all properties:

• getter will return value of bound property of X
• setter will apply value change back to Y

This library uses Lamar Code Weaving for runtime IL generation, InfoViaLinq to extract PropertyInfo from MemberExpression and Guard for validation.

How to use:

Given class:

public class Entity
{
    public string Name { get; set; }
    
    public int Age { get; set; }
    
    public bool Alive { get; set; }
    
    public Guid Id { get; set; }
}

And interface:

public interface ICommon
{
    string NameC { get; set; }

    bool AliveC { get; set; }
}

We can generate a bound type:

var boundType = ObjectBinderBuilder.New<Entity, ICommon>()
    .Bind(x => x.Name, x => x.NameC)
    .Bind(x => x.Alive, x => x.AliveC)
    .Build()
    .BoundType;
    
var sourceObj = new Entity { ... };
var proxy = (ICommon) Activator.CreateInstance(boundType, sourceObj);

proxy.NameC = "Something else...";

// Assert property change in `sourceObj`
Assert.Equals(sourceObj.Name, proxy.NameC);

Runtime generated class:

public class ICommon_proxy_0 : ICommon {
    
    private readonly Entity _source = source;
    
    public ICommon_proxy_0(Entity source) { _source = source; }
    
    public string NameC { get { return _source.Name; } set { _source.Name = value; } }
    
    public bool AliveC { get { return _source.Alive; } set { _source.Alice = value; } }
}

Note:

This library is useful when we are dealing with a class with many many properties and we want to map it to another class with smaller set of properties where changes to simplified object properties will be applied back to original object properties.

Credit:

Special thanks to @alexsniffin who came up with the original idea.