bubdm / fluentproxies

A library that allows for creation of dynamic proxies that extend functionality of existing objects.

FluentProxies

A library that allows for creation of dynamic proxies that provide additional functionality to existing objects, such as implementing the INotifyPropertyChanged interface or adding custom properties and interfaces.

Installation

Via NuGet:

PM> Install-Package FluentProxies

Usage

To create a proxy, call the CreateProxy method on the ProxyBuilder class. Add any desired functionality to a proxy using method chaining on the builder object. When you are done, call the Build method to build the proxy using the provided configuration.

Person person = new Person
{
  Name = "Jack",
  Age = 26,
};

Person proxy = ProxyBuilder.CreateProxy(person)
  .SyncWithReference()
  .Implement(Implementations.INotifyPropertyChanged)
  .Build();

Prerequisites

To create a proxy, the object must define at least one public, non-static property. Additionally, all public, non-static properties must be marked as virtual. You can check for any configuration errors before building a proxy by checking the IsValid property. However, the build method will still throw an exception is some cases (for example, if you define a custom interface on a proxy without providing all of the necessary interface members).

Syncing with reference

Calling the SyncWithReference method on a builder object will make it so the properties on the proxy object itself will have no value of their own, instead they will be linked to the getters and setters of properties on the source object the proxy was created from.

Person proxy = ProxyBuilder.CreateProxy(person)
  .SyncWithReference()
  .Build();
  
proxy.Name = "Nick";
Console.WriteLine(person.Name);

person.Age = 30;
Console.WriteLine(proxy.Age);

Output:
Nick
30

If you do not choose to sync with reference, the proxy object will retain the property values at the moment of proxy creation, but will not influence or be influenced by the original object from that point onwards - the proxy will be an entirely different instance with no connection to the original object it was created from.

Implementations

You can add one of the predefined implementations to a proxy using the Implement method. The snippet below will create a proxy implementing the INotifyPropertyChanged interface on all of its public, non-static properties.

Person proxy = ProxyBuilder.CreateProxy(person)
  .Implement(Implementations.INotifyPropertyChanged)
  .Build();

Custom properties

You can add a simple public property to a proxy by calling the AddProperty method.

Person proxy = ProxyBuilder.CreateProxy(person)
  .AddProperty<bool>("IsSpecialUser")
  .Build();

Custom interfaces

You can also make the proxy implement a custom interface. The proxy must provide all of the necessary interface members, otherwise an exception will be thrown when calling the Build method.

Person proxy = ProxyBuilder.CreateProxy(person)
  .AddInterface<IPerson>()
  .Build();

Proxy wrappers

If you chose the option to sync with reference, a property of type ProxyWrapper<T> will be added to a proxy. The wrapper contains the reference to the original object the proxy was created from. You can access the wrapper by calling the GetWrapper<T> method on the ProxyBuilder class.

ProxyWrapper<Person> wrapper = ProxyBuilder.GetWrapper<Person>(proxy);
wrapper.SourceReference.Name = "Ryan";