Expression Member Name | C# Online Compiler

Expression Member Name by Farquaad

using System;
using System.Linq;
using System.Linq.Expressions;					
using System.Collections.Generic;

public class Program
{
	public static void Main()
	{
		var p = new Person { FirstName = "Bill", LastName= "Gates", MiddleName = string.Empty, Age = 62};

		Console.WriteLine(Extensions.GetName(() => p.FirstName));
		Console.WriteLine(Extensions.GetName(() => p.LastName));
		Console.WriteLine(Extensions.GetName(() => p.Age));
		Console.WriteLine(Extensions.GetName(() => p.Birthdate));
		Console.WriteLine(Extensions.GetName(() => p.Parents));

		Console.WriteLine(Extensions.GetName(() => p.Age.ToString()));


		Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.FirstName));
		Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.LastName));
		Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.MiddleName));
	}

	// Define other methods and classes here
	public class Person
	{
		public string FirstName { get; set; }
		public string MiddleName { get; set; }
		public string LastName { get; set; }
		public int Age { get; set; }
		public DateTime Birthdate { get; set; }
		public List<Person> Parents { get; set; }
	}
}

	public static class Extensions
	{	
		public static string GetName<T>(this Expression<Func<T>> action)
		{
			return GetNameFromMemberExpression(action.Body);
		}
		static string GetNameFromMemberExpression(Expression expression) {
			if (expression is MemberExpression) {
				return (expression as MemberExpression).Member.Name;
			}
			else if (expression is UnaryExpression) {
				return GetNameFromMemberExpression((expression as UnaryExpression).Operand);
			}
			return "MemberNameUnknown";
		}


		public static bool EnsureNotNullOrEmpty(Expression<Func<string>> member)
		{
			var memberValue = member.Compile()();
			if (string.IsNullOrEmpty(memberValue.ToString()))
			{
				throw new ArgumentException($"This property cannot be null or empty.", member.GetName());
			}
			return true;
		}
	}

​x
 
using System;
using System.Linq;
using System.Linq.Expressions;                  
using System.Collections.Generic;
​
public class Program
{
    public static void Main()
    {
        var p = new Person { FirstName = "Bill", LastName= "Gates", MiddleName = string.Empty, Age = 62};
​
        Console.WriteLine(Extensions.GetName(() => p.FirstName));
        Console.WriteLine(Extensions.GetName(() => p.LastName));
        Console.WriteLine(Extensions.GetName(() => p.Age));
        Console.WriteLine(Extensions.GetName(() => p.Birthdate));
        Console.WriteLine(Extensions.GetName(() => p.Parents));
​
        Console.WriteLine(Extensions.GetName(() => p.Age.ToString()));
​
​
        Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.FirstName));
        Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.LastName));
        Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.MiddleName));
    }
​
    // Define other methods and classes here
    public class Person
    {
        public string FirstName { get; set; }
        public string MiddleName { get; set; }
        public string LastName { get; set; }
        public int Age { get; set; }
        public DateTime Birthdate { get; set; }
        public List<Person> Parents { get; set; }
    }
}
​
    public static class Extensions
    {   
        public static string GetName<T>(this Expression<Func<T>> action)
        {
            return GetNameFromMemberExpression(action.Body);
        }
        static string GetNameFromMemberExpression(Expression expression) {
            if (expression is MemberExpression) {
                return (expression as MemberExpression).Member.Name;
            }
            else if (expression is UnaryExpression) {
                return GetNameFromMemberExpression((expression as UnaryExpression).Operand);
            }
            return "MemberNameUnknown";
        }
​
​
        public static bool EnsureNotNullOrEmpty(Expression<Func<string>> member)
        {
            var memberValue = member.Compile()();
            if (string.IsNullOrEmpty(memberValue.ToString()))
            {
                throw new ArgumentException($"This property cannot be null or empty.", member.GetName());
            }
            return true;
        }
    }

Compilation error (line 4, col 7): The type or namespace name 'Json' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 36, col 21): The type or namespace name 'JsonSchema' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 51, col 28): The type or namespace name 'JsonSchema' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 22, col 26): The name 'JsonSchema' does not exist in the current context
Compilation error (line 36, col 51): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 37, col 25): The type or namespace name 'Dictionary<,>' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 37, col 44): The type or namespace name 'JsonSchema' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 39, col 28): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 40, col 31): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 43, col 28): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 44, col 31): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 51, col 59): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 52, col 15): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 53, col 17): The name 'MetaSchemas' does not exist in the current context
Compilation error (line 56, col 25): The type or namespace name 'Dictionary<,>' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 56, col 44): The type or namespace name 'JsonSchema' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 59, col 30): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 60, col 23): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 67, col 32): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 68, col 23): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 75, col 31): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 76, col 23): The name 'SchemaValueType' does not exist in the current context
Compilation error (line 78, col 28): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 79, col 25): The type or namespace name 'JsonSchemaBuilder' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 83, col 19): The type or namespace name 'Dictionary<,>' could not be found (are you missing a using directive or an assembly reference?)
Compilation error (line 83, col 38): The type or namespace name 'JsonSchema' could not be found (are you missing a using directive or an assembly reference?)

Last Run:	10:18:09 pm
Compile:	0.007s
Execute:	0s
Memory:	0b
CPU:	0s

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