ArrayParameterCollection.cs

using System;
using System.Collections.Generic;

namespace HttpServer
{
    /// <summary>
    /// Form parameters where form string arrays have been converted to real arrays.
    /// </summary>
    public class ArrayParameterCollection : Parameter, IParameterCollection
    {
        private readonly Dictionary<string, IParameter> _items =
            new Dictionary<string, IParameter>(StringComparer.OrdinalIgnoreCase);

        /// <summary>
        /// Initializes a new instance of the <see cref="ArrayParameterCollection"/> class.
        /// </summary>
        public ArrayParameterCollection() : base("root", string.Empty)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ArrayParameterCollection"/> class.
        /// </summary>
        /// <param name="name">The name.</param>
        /// <param name="value">The value.</param>
        protected ArrayParameterCollection(string name, string value)
            : base(name, value)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ArrayParameterCollection"/> class.
        /// </summary>
        /// <param name="collection">Parse parameters from the this collection.</param>
        public ArrayParameterCollection(IEnumerable<IParameter> collection) : base("root", string.Empty)
        {
            foreach (var item in collection)
            {
                foreach (var value in item)
                    Add(item.Name, value);
            }
        }

        /// <summary>
        /// Gets first value of an item.
        /// </summary>
        /// <value></value>
        /// <returns>String if found; otherwise <c>null</c>.</returns>
        public ArrayParameterCollection this[string name]
        {
            get { return GetItem(name); }
        }

        private ArrayParameterCollection GetItem(string name)
        {
            IParameter parameter;
            if (!_items.TryGetValue(name, out parameter))
                return null;

            return (ArrayParameterCollection) parameter;
        }

        #region IParameterCollection Members

        /// <summary>
        /// Get a parameter.
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public IParameter Get(string name)
        {
            return GetItem(name);
        }

        /// <summary>
        /// Add a parameter
        /// </summary>
        /// <param name="name">Name of parameter, can contain a string array.</param>
        /// <param name="value">Value</param>
        /// <example>
        /// <code>
        /// ArrayParameterCollection array = new ArrayParameterCollection();
        /// array.Add("user[FirstName]", "Jonas");
        /// array.Add("user[FirstName]", "Arne");
        /// string firstName = array["user"]["FirstName"].Value; // "Arne" is returned
        /// foreach (string value in array["user"]["FirstName"])
        ///   Console.WriteLine(value);  // each name is displayed.
        /// </code>
        /// </example>
        public void Add(string name, string value)
        {
            int pos = name.IndexOf('[');
            if (pos != -1)
            {
                string myName = name.Substring(0, pos);
                name = name.Remove(0, pos + 1);
            	pos = name.IndexOf(']');
                name = name.Remove(pos, 1);

                ArrayParameterCollection mine = GetItem(myName);
                if (mine == null)
                {
                    mine = new ArrayParameterCollection(myName, string.Empty);
                    _items.Add(myName, mine);
                }

                mine.Add(name, value);
                return;
            }

            // new parameter
            ArrayParameterCollection current = GetItem(name);
            if (current == null)
            {
                current = new ArrayParameterCollection(name, value);
                _items.Add(name, current);
                return;
            }

            // existing
            current.Values.Add(value);
        }

        /// <summary>
        /// Checks if the specified parameter exists
        /// </summary>
        /// <param name="name">Parameter name.</param>
        /// <returns><c>true</c> if found; otherwise <c>false</c>;</returns>
        public bool Exists(string name)
        {
            return _items.ContainsKey(name);
        }

        /// <summary>
        /// Gets number of parameters.
        /// </summary>
        public int Count
        {
            get { return _items.Count; }
        }

        /// <summary>
        /// Gets last value of an parameter.
        /// </summary>
        /// <param name="name">Parameter name</param>
        /// <returns>String if found; otherwise <c>null</c>.</returns>
        string IParameterCollection.this[string name]
        {
            get { return GetItem(name).Value; }
        }

        /// <summary>
        /// Returns an enumerator that iterates through the collection.
        /// </summary>
        /// <returns>
        /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
        /// </returns>
        /// <filterpriority>1</filterpriority>
        public IEnumerator<IParameter> GetEnumerator()
        {
            return _items.Values.GetEnumerator();
        }

        #endregion
    }
}