LiteWare.ObjectInvokers 0.1.0

LiteWare.ObjectInvokers

Dynamically invoke methods and modify properties or fields of an object by referencing the member's name. This is done via the ObjectInvoker.Invoke method which accepts a member name and any generic types and/or parameters and redirects the call to a concrete object.

Depending on the underlying concrete object member, the invoke process can:

• Invoke a method and return the result if the member is a method:

  bool success = (bool)objectInvoker.Invoke("SetLightSwitchState", "SW012", LightSwitchState.On)!;
  

• Get or set a property if the member is a property:

  string id = (string)objectInvoker.Invoke("DeviceId")!; // Property getter
  objectInvoker.Invoke("DeviceDescription", "Livingroom light switch"); // Property setter
  

• Get or set a field value if the member is a field:

  int timeout = (int)objectInvoker.Invoke("Timeout")!; // Get field value
  objectInvoker.Invoke("Timeout", 1000); // Set field value
  

This library is useful in scenarios like RPC/RMI, where a remote endpoint wants to invoke a local method by specifying its name.

Installation

The library is available as a Nuget Package.

Usage

To dynamically invoke members by member name, an ObjectInvoker needs to be created, usually by binding a contract type containing the members to invoke to an instance of the contract:

ObjectInvoker objectInvoker = ObjectInvoker.Bind<IMyService>(myService);

The contract type is not limited to only interfaces and can be of any type. However, it must have members qualified by the InvokableMemberAttribute so that they can be invoked:

public interface IMyService
{
    [InvokableMember]
    int MyProperty { get; set; }

    [InvokableMember]
    void MyProcedure();

    [InvokableMember("MyFunction")]
    int SomeFunction(int arg);
}

InvokableMemberAttribute can also be applied on private members.

Finally, the members can be dynamically invoked by member name:

int result = (int)objectInvoker.Invoke("MyFunction", 123)!;