/// <summary>
/// Gets the value of this property given the instance. If the property is <see langword="static"/>, pass <see langword="null"/> on the target.
/// </summary>
/// <exception cref="InvalidOperationException">Thrown when the property has no getter or the target is <see langword="null"/> and the property is not <see langword="static"/></exception>
/// <param name="target">The target instance. Pass <see langword="null"/> if the property is <see langword="static"/>.</param>
/// <returns>The value of the property.</returns>
public object?GetValue(object?target)
{
if (_get is null)
{
Throw.InvalidOperation($"The property {Member.DeclaringType}.{Member.Name} doesn't contain a getter.");
}
if (target is null && !IsStatic)
{
Throw.InvalidOperation($"The target cannot be null because {Member.DeclaringType}.{Member.Name} is not an static property.");
}
return(_get(target));
}
public object CreateInstance()
{
if (_target.IsAbstract)
{
Throw.InvalidOperation("You cannot create an instance of an abstract type.");
}
if (Parameters.Count > 0)
{
Throw.InvalidOperation($"This constructor {_target.Name}({string.Join(", ", Parameters.Select(x => x.ParameterType.Name))}) requires these parameters to be used.");
}
return(Factory.CreateInstance(_target));
}
public object CreateInstance([NotNull] params object[] args)
{
if (args is null)
{
Throw.NullArgument(nameof(args));
}
if (_target.IsAbstract)
{
Throw.InvalidOperation("You cannot create an instance of an abstract type.");
}
if (args.Length != Parameters.Count)
{
Throw.ParameterCountMismatch($"This constructor {_target.Name}({string.Join(", ", Parameters.Select(x => x.ParameterType.Name))}) requires these parameters to be used.");
}
for (var index = 0; index < args.Length; index++)
{
if (!args[index].GetType().CanBeConvertedTo(Parameters[index].ParameterType))
{
Throw.InvalidOperation($"The type {args[index].GetType().Name} cannot be implicitly converted to {Parameters[index].ParameterType.Name}");
}
}
if (_constructor is object)
{
return(_constructor(args));
}
var array = Expression.Parameter(typeof(object[]));
var parameters = args
.Zip(Enumerable.Range(0, args.Length),
(arg, index) => Expression.Convert(
Expression.ArrayIndex(
array,
Expression.Constant(index)),
arg.GetType()))
.ToArray();
var @new = Expression.New(Member, parameters);
var convert = Expression.Convert(@new, typeof(object));
_constructor = Expression.Lambda <Func <object[], object> >(convert, array).Compile();
return(_constructor(args));
}
/// <summary>
/// Sets the value of this property given the instance and the value. If the property is <see langword="static"/>, pass <see langword="null"/> on the target.
/// </summary>
/// <exception cref="InvalidOperationException">Thrown when the property has no setter, the target is <see langword="null"/> and the property is not <see langword="static"/> or the value is <see langword="null"/> and the property is not nullable.</exception>
/// <param name="target">The target instance. Pass <see langword="null"/> if the property is <see langword="static"/>.</param>
/// <param name="value">The value.</param>
public void SetValue(object?target, object?value)
{
if (_set is null)
{
Throw.InvalidOperation($"The property {Member.DeclaringType}.{Member.Name} doesn't contain a setter.");
}
if (target is null && !IsStatic)
{
Throw.InvalidOperation($"The target cannot be null because {Member.DeclaringType}.{Member.Name} is not an static property.");
}
if (value is null && !IsNullable)
{
Throw.InvalidOperation($"The value cannot be null because {Member.DeclaringType}.{Member.Name} is of type {PropertyType}, which is not a nullable type (class, interface or Nullable<T>)");
}
_set(target, value);
}
