A Reflection.Emit based version of DataBinder.Eval

CompileDataBinder.cs

using System;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;

class Program
{
    static void Main(string[] args)
    {
        Person model = new Person
        {
            Id = 123,
            FullName = new FullName
            {
                FirstName = "Duncan",
                LastName = "Smart",
            }
        };

        var nameBinder = CompileDataBinder<Person, string>("model.FullName.FirstName");
        string fname = nameBinder(model);
        Debug.Assert(fname == "Duncan");

        // Note how here we pretend we don't know TProp type
        var idBinder = CompileDataBinder<Person, object>("model.Id");
        object id = idBinder(model);
        Debug.Assert(id.Equals(123));
    }

    static Func<TModel, TProp> CompileDataBinder<TModel, TProp>(string expression)
    {
        var propNames = expression.Split('.');

        var model = Expression.Parameter(typeof(TModel), "model");

        Expression body = model;
        foreach (string propName in propNames.Skip(1))
            body = Expression.Property(body, propName);
        //Debug.WriteLine(prop);

        if (body.Type != typeof(TProp))
            body = Expression.Convert(body, typeof(TProp));

        Func<TModel, TProp> func = Expression.Lambda<Func<TModel, TProp>>(body, model).Compile();
        //TODO: cache funcs
        return func;
    }
}

class Person
{
    public int Id { get; set; }
    public FullName FullName { get; set; }
}

class FullName
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}