MetadataPropertyCollection.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Metadata / Edm / MetadataPropertyCollection.cs / 1305376 / MetadataPropertyCollection.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Data.Common;
using System.Diagnostics;
using System.Reflection; 
using System.Data.Common.Utils;
 
namespace System.Data.Metadata.Edm 
{
    ///  
    /// Metadata collection class supporting delay-loading of system item attributes and
    /// extended attributes.
    /// 
    internal sealed class MetadataPropertyCollection : MetadataCollection 
    {
        ///  
        /// Constructor taking item. 
        /// 
        /// Item with which the collection is associated. 
        internal MetadataPropertyCollection(MetadataItem item)
            : base(GetSystemMetadataProperties(item))
        {
        } 

        private readonly static Memoizer s_itemTypeMemoizer = 
            new Memoizer(clrType => new ItemTypeInformation(clrType), null); 

        // Given an item, returns all system type attributes for the item. 
        private static IEnumerable GetSystemMetadataProperties(MetadataItem item)
        {
            EntityUtil.CheckArgumentNull(item, "item");
            Type type = item.GetType(); 
            ItemTypeInformation itemTypeInformation = GetItemTypeInformation(type);
            return itemTypeInformation.GetItemAttributes(item); 
        } 

        // Retrieves metadata for type. 
        private static ItemTypeInformation GetItemTypeInformation(Type clrType)
        {
            return s_itemTypeMemoizer.Evaluate(clrType);
        } 

        ///  
        /// Encapsulates information about system item attributes for a particular item type. 
        /// 
        private class ItemTypeInformation 
        {
            /// 
            /// Retrieves system attribute information for the given type.
            /// Requires: type must derive from MetadataItem 
            /// 
            /// Type 
            internal ItemTypeInformation(Type clrType) 
            {
                Debug.Assert(null != clrType); 

                _itemProperties = GetItemProperties(clrType);
            }
 
            private readonly List _itemProperties;
 
            // Returns system item attributes for the given item. 
            internal IEnumerable GetItemAttributes(MetadataItem item)
            { 
                foreach (ItemPropertyInfo propertyInfo in _itemProperties)
                {
                    yield return propertyInfo.GetMetadataProperty(item);
                } 
            }
 
            // Gets type information for item with the given type. Uses cached information where 
            // available.
            private static List GetItemProperties(Type clrType) 
            {
                List result = new List();
                foreach (PropertyInfo propertyInfo in clrType.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
                { 
                    foreach (MetadataPropertyAttribute attribute in propertyInfo.GetCustomAttributes(
                        typeof(MetadataPropertyAttribute), false)) 
                    { 
                        result.Add(new ItemPropertyInfo(propertyInfo, attribute));
                    } 
                }
                return result;
            }
        } 

 
        ///  
        /// Encapsulates information about a CLR property of an item class.
        ///  
        private class ItemPropertyInfo
        {
            /// 
            /// Initialize information. 
            /// Requires: attribute must belong to the given property.
            ///  
            /// Property referenced. 
            /// Attribute for the property.
            internal ItemPropertyInfo(PropertyInfo propertyInfo, MetadataPropertyAttribute attribute) 
            {
                Debug.Assert(null != propertyInfo);
                Debug.Assert(null != attribute);
 
                _propertyInfo = propertyInfo;
                _attribute = attribute; 
            } 

            private readonly MetadataPropertyAttribute _attribute; 
            private readonly PropertyInfo _propertyInfo;

            /// 
            /// Given an item, returns an instance of the item attribute described by this class. 
            /// 
            /// Item from which to retrieve attribute. 
            /// Item attribute. 
            internal MetadataProperty GetMetadataProperty(MetadataItem item)
            { 
                return new MetadataProperty(_propertyInfo.Name, _attribute.Type, _attribute.IsCollectionType,
                    new MetadataPropertyValue(_propertyInfo, item));
            }
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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MetadataPropertyCollection.cs source code in C# .NET

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