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

using System;
using System.ComponentModel;
using System.Collections;

namespace PetShop.Business{
  /// <summary>
    /// List of possible state for an entity.
    /// </summary>
  public enum EntityState
    {
        /// <summary>
        /// Entity is unchanged
        /// </summary>
        Unchanged=0, 

        /// <summary>
        /// Entity is new
        /// </summary>
        Added=1, 

        /// <summary>
        /// Entity has been modified
        /// </summary>
        Changed=2, 

        /// <summary>
        /// Entity has been deleted
        /// </summary>
        Deleted=3
    }
  
  /// <summary>
  /// The interface that each business object of the model implements.
  /// </summary>
  public interface IEntity
  {
    /// <summary>
    ///  The name of the underlying database table.
    /// </summary>
    string TableName { get;}

    /// <summary>
    ///  Indicates if the object has been modified from its original state.
    /// </summary>
    ///<value>True if object has been modified from its original state; otherwise False;</value>
    bool IsDirty {get;}
    
    /// <summary>
    ///  Indicates if the object is new.
    /// </summary>
    ///<value>True if objectis new; otherwise False;</value>
    bool IsNew {get;}

    /// <summary>
    /// True if object has been marked as deleted. ReadOnly.
    /// </summary>
    bool IsDeleted {get;}

    /// <summary>
    /// Indicates if the object is in a valid state
    /// </summary>
    /// <value>True if object is valid; otherwise False.</value>
    bool IsValid { get;}
        
    /// <summary>
    /// Returns one of EntityState enum values - intended to replace IsNew, IsDirty, IsDeleted.
    /// </summary>
    EntityState EntityState {get;}
    
    /// <summary>
    /// Accepts the changes made to this object by setting each flags to false.
    /// </summary>
    void AcceptChanges();
    
    /// <summary>
    /// Marks entity to be deleted.
    /// </summary>
    void MarkToDelete();
         
    /// <summary>
        /// Gets or sets the parent collection.
        /// </summary>
        /// <value>The parent collection.</value>
    object ParentCollection{get;set;}
    
    /// <summary>
    ///    The name of the underlying database table's columns.
    /// </summary>
    /// <value>A string array that holds the columns names.</value>
    string[] TableColumns {get;}
    
    
    /// <summary>
    ///     Gets or sets the object that contains supplemental data about this object.
    /// </summary>
    /// <value>Object</value>
    object Tag { get;set;}
    
    /// <summary>
    /// Determines whether the property value has changed from the original data.
    /// </summary>
    /// <param name="columnName">The column name.</param>
    /// <returns>
    ///   <c>true</c> if the property value has changed; otherwise, <c>false</c>.
    /// </returns>
    bool IsPropertyChanged(string columnName);
    
    /// <summary>
        /// Event to indicate that a property has changed.
        /// </summary>
    event PropertyChangedEventHandler PropertyChanged;
    
    /// <summary>
    /// Determines whether this entity is being tracked.
    /// </summary>
    bool IsEntityTracked {  get;  set;  }
    
    ///<summary>
    /// The tracking key used to with the <see cref="EntityLocator" />
    ///</summary>
    string EntityTrackingKey {  get;  set;  }
  }
  
  /// <summary>
  ///     Interface that TList and every entity implements to support
  ///    cloning of an object tree.
  /// </summary>
  public interface ICloneableEx
  {
    ///<summary>
    /// The tracking key used to with the <see cref="EntityLocator" />
    ///</summary>
    ///<param name="existingCopies">A list containing references to all objects already copied.</param>
    object Clone(IDictionary existingCopies);
  }
}