/// <summary> [EXPERIMENTAL] Gets the specified property. When lazy initialization occurs, the specified initialization function is used.
/// </summary>
/// <typeparam name="TRet">The type of the return value.</typeparam>
/// <param name="propertyExpression">The property expression.</param>
/// <param name="valueFactory">The delegate that is invoked to produce the lazily initialized value when it is needed.</param>
/// <returns>The value</returns>
/// <exception cref="System.Collections.Generic.KeyNotFoundException"></exception>
public TRet GetValue <TRet>([NotNull] Expression <Func <TRet> > propertyExpression, [NotNull] Func <TRet> valueFactory)
{
if (valueFactory == null)
{
throw new ArgumentNullException(nameof(valueFactory));
}
var name = MemberNameUtil.GetPropertyName(propertyExpression);
if (!_fields.ContainsKey(name))
{
if (_readOnlyCollection)
{
throw new KeyNotFoundException();
}
var value = valueFactory();
AddCore(name, value);
if (Equals(value, default(TRet)))
{
OnPropertyChanged(name, default(TRet), value);
}
}
return((TRet)_fields[name].Value);
}
/// <summary> Example: this.ℝ(x => x.Parent.Parent)
/// </summary>
/// <typeparam name="TIn"></typeparam>
/// <typeparam name="TOut"></typeparam>
/// <param name="v"></param>
/// <param name="f"></param>
/// <returns></returns>
public static TOut ℝ <TIn, TOut>(this TIn v, Expression <Func <TIn, TOut> > f) where TIn : class where TOut : class
{
var path = MemberNameUtil.SplitPropertyPath(f).ToList();
var o = (object)v;
path.RemoveAt(0);
while (path.Count > 0)
{
if (o == null)
{
return(null);
}
var m = path[0]; path.RemoveAt(0);
var propertyInfo = o.GetType().GetProperty(m);
o = propertyInfo.GetValue(o, null);
}
return((TOut)o);
// var compiledExpression = f.Compile();
// var result = compiledExpression(v);
//
// return result;
}
public IBackingFieldInfo this[Expression <Func <object> > memberExpression] => _fields[MemberNameUtil.GetPropertyName(memberExpression)];
public void Add <T>(Expression <Func <T> > memberExpression, T value = default(T))
{
Add(MemberNameUtil.GetPropertyName(memberExpression), value);
}