// C# Eval Expression

// Doc: https://eval-expression.net/register-unregister

​

// @nuget: Z.Expressions.Eval

​

/*

## RegisterMember

​

The RegisterMember method registers all instance members from the types or fields list provided. A member is a Property, Field, Method, or Constructor.

​

In this example, we will first set our context in safe mode with `context.SafeMode = true;` and unregister all current types with `context.UnregisterAll();`. We need to set `SafeMode = true` as; otherwise, members such as methods will be automatically accessible. In the first expression, we will try to access the `GetCustomerID` method, which will fail since we are in `SafeMode`, and then we will register the member and try again, which this time will success. To finish, we will use our methods `IsRegisteredMember` and `UnregisterMember` to unregister all methods from our `Customer` type and make sure it has been successfully unregistered.

​

See more: https://eval-expression.net/register-unregister

*/

​

using System;

using System.Collections.Generic;

using Z.Expressions;

​

public class Program

{

    public static void Main()

    {

        // Global Context: EvalManager.DefaultContext.RegisterMember(typeof(Customer));

        var context = new EvalContext();

        context.SafeMode = true;

        context.UnregisterAll();        

        var customer = new Customer() { CustomerID = 1 };

        try

        {

            var fail = context.Execute<int>("GetCustomerID()", customer);

        }

        catch(Exception ex)

        {

            Console.WriteLine("1 - Exception: " + ex.Message);

        }

        context.RegisterMember(typeof(Customer));       

        var r2 = context.Execute<int>("GetCustomerID()", customer);

        Console.WriteLine("2 - Result: " + r2);

        // Check if all members of the type `Customer` is registered

        var r3 = context.IsRegisteredMember(typeof(Customer)); // return true

        Console.WriteLine("3 - Result: " + r3);

        // Unregister all members of the type `Customer`

        context.UnregisterMember(typeof(Customer));

        // Check if all members of the type `Customer` has been succesfully unregistered

        var r4 = context.IsRegisteredMember(typeof(Customer)); // return false

        Console.WriteLine("4 - Result: " + r4);

    }

    public class Customer

    {

        public int CustomerID { get; set; }

        public int GetCustomerID()

        {

            return CustomerID;

        }

    }

}