using System.Collections.Generic;

namespace Chernobyl.DesignPatterns.Extension
{
    /// <summary>
    /// An interface for working with instances that can be extended using the
    /// <see cref="IExtension"/> or <see cref="IExtension{TExtended}"/> 
    /// type. Note that the <see cref="IExtension{TExtended}"/> type 
    /// does not require a type to be an <see cref="IExtendable"/> for it to be 
    /// extended. But, it is still highly recommended that the extension add 
    /// itself to the  <see cref="Extensions"/> list of the instance when it is 
    /// attaching to that instance and remove itself when it is detaching from 
    /// that instance.
    /// </summary>
    public interface IExtendable
    {
        /// <summary>
        /// The list of <see cref="IExtension"/> or 
        /// <see cref="IExtension{TExtended}"/> instances that have 
        /// attached themselves to this instance.
        /// </summary>
        IList<IExtension> Extensions { get; }
    }
}