EntityLocator.cs :  » Template-Engines » netTiers » PetShop » Business » C# / CSharp Open Source

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Practices.ObjectBuilder2;


namespace PetShop.Business{
    /// <summary>
    /// Provides a means to weak reference and already created and untouched locate entities.
    /// </summary>  
    public class EntityLocator : Microsoft.Practices.ObjectBuilder2.Locator 
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="EntityLocator"/> class.
        /// </summary>
        public EntityLocator() 
            : base(null)
        { 
        }

        /// <summary>
        /// Adds the specified key.
        /// </summary>
        /// <param name="key">The key.</param>
        /// <param name="value">The value.</param>
        public void Add(string key, object value)
        {
            base.Add(key as object, value);
        }

        /// <summary>
        /// Determines whether [contains] [the specified key].
        /// </summary>
        /// <param name="key">The key.</param>
        /// <returns>
        ///   <c>true</c> if [contains] [the specified key]; otherwise, <c>false</c>.
        /// </returns>
        public bool Contains(string key)
        {
            return base.Contains(key);
        }


        /// <summary>
        /// Gets the specified key of any object.
        /// </summary>
        /// <param name="key">The key.</param>
        /// <returns>object if available, else null </returns>
        public override object Get(object key)
        {
            return base.Get(key);
        }

        /// <summary>
        /// Get's an Entity from the Tracking Locator
        /// </summary>
        /// <typeparam name="Entity">A type that implements IEntity</typeparam>
        /// <param name="key">locator list key to fetch, best used 
        /// if it's the (TypeName or TableName) + EntityKey of the this entity</param>
        /// <returns>Entity from Locator if available.</returns>
        public Entity GetEntity<Entity>(string key) where Entity : EntityBase, new()
        {
            return Get(key as object) as Entity;
        }

        /// <summary>
        /// Get's a List of Entities from the Tracking Locator
        /// </summary>
        /// <typeparam name="EntityList"> a type that implements ListBase&lt;IEntity&gt;</typeparam>
        /// <param name="key">locator list key to fetch, best used 
        /// if it's like the criteria of the method used to populate this list
        /// </param>
        /// <returns>ListBase&lt;IEntity&gt; if available</returns>
        public EntityList GetList<EntityList>(string key) where EntityList : ListBase<IEntity>, new()
        {
            return Get(key as object) as EntityList;
        }
    
    
        /// <summary>
        /// Re-Creates the key based on primary key values.
        /// </summary>
        /// <param name="type">The type.</param>
        /// <param name="pkItems">The pk items.</param>
        /// <returns></returns>
    public static string ConstructKeyFromPkItems(Type type, params object[] pkItems)
    {
      if (type == null)
        throw new ArgumentNullException("type");
      
      if (pkItems.Length == 0)
        throw new ArgumentNullException("pkItems");
        
      System.Text.StringBuilder sb = new System.Text.StringBuilder();
      sb.Append(type.Name);
      
      for(int i=0; i < pkItems.Length; i++)
      {
        if (pkItems[i] != null)
          sb.Append("|").Append(pkItems[i].ToString());
      }
      
      return sb.ToString();
    }
  }

}