EntityDataSourceWrapper.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataWebControls / System / Data / WebControls / EntityDataSourceWrapper.cs / 1305376 / EntityDataSourceWrapper.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 
using System;
using System.Data; 
using System.Configuration;
using System.ComponentModel;
using System.Data.Common;
using System.Data.Metadata.Edm; 
using System.Reflection;
using System.Data.Objects; 
using System.Data.Objects.DataClasses; 
using System.Collections.Generic;
using System.Diagnostics; 
using System.Linq;
using System.Collections.ObjectModel;
using System.Text;
using System.Web.UI; 

namespace System.Web.UI.WebControls 
{ 
    /// 
    /// Wraps an entity displayed in the data source in an ICustomTypeDescriptor 
    /// implementation that flattens complex types and exposes references.
    /// 
    internal class EntityDataSourceWrapper : ICustomTypeDescriptor
    { 
        private readonly EntityDataSourceWrapperCollection _collection;
        private readonly ObjectStateEntry _stateEntry; 
 
        internal EntityDataSourceWrapper(EntityDataSourceWrapperCollection collection, object trackedEntity)
        { 
            EntityDataSourceUtil.CheckArgumentNull(collection, "collection");
            EntityDataSourceUtil.CheckArgumentNull(trackedEntity, "trackedEntity");

            this._collection = collection; 

            // retrieve state entry 
            if (!this._collection.Context.ObjectStateManager.TryGetObjectStateEntry(trackedEntity, out _stateEntry)) 
            {
                throw new ArgumentException(Strings.ComponentNotFromProperCollection, "trackedEntity"); 
            }
        }

        ///  
        /// Gets entity wrapped by this type descriptor.
        ///  
        internal object WrappedEntity 
        {
            get 
            {
                return this._stateEntry.Entity;
            }
        } 

        internal RelationshipManager RelationshipManager 
        { 
            get
            { 
                return this._stateEntry.RelationshipManager;
            }
        }
 
        /// 
        /// Gets collection containing this wrapper. 
        ///  
        internal EntityDataSourceWrapperCollection Collection
        { 
            get { return this._collection; }
        }

        #region ICustomTypeDescriptor Implementation 
        System.ComponentModel.AttributeCollection System.ComponentModel.ICustomTypeDescriptor.GetAttributes() { return new System.ComponentModel.AttributeCollection(); }
        string ICustomTypeDescriptor.GetClassName() { return null; } 
        string ICustomTypeDescriptor.GetComponentName() { return null; } 
        TypeConverter ICustomTypeDescriptor.GetConverter() { return null; }
        EventDescriptor ICustomTypeDescriptor.GetDefaultEvent() { return null; } 
        PropertyDescriptor ICustomTypeDescriptor.GetDefaultProperty() { return null; }
        object ICustomTypeDescriptor.GetEditor(Type editorBaseType) { return null; }
        EventDescriptorCollection ICustomTypeDescriptor.GetEvents() { return null; }
        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attributes) { return null; } 

 
        public PropertyDescriptorCollection GetProperties() 
        {
            return ((ITypedList)this._collection).GetItemProperties(null); 
        }

        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attributes)
        { 
            return ((ICustomTypeDescriptor)this).GetProperties();
        } 
 
        object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor pd)
        { 
            return this.WrappedEntity;
        }
        #endregion ICustomTypeDescriptor Implementation
 
        /// 
        /// Use this method to set the properties on the wrapped entity 
        ///  
        /// 
        ///  
        /// 
        internal void SetAllProperties(Dictionary propertiesFromViewState, bool overwriteSameValue,
            ref Dictionary propertySettingExceptionsCaught)
        { 
            // We aggregate the reference descriptors rather than setting them directly
            // to account for compound keys (we need all components of the key to create 
            // an EntityKey that can be set on the EntityReference) 
            var referenceList = new List>();
 
            foreach (EntityDataSourceWrapperPropertyDescriptor descriptor in _collection.AllPropertyDescriptors)
            {
                // figure out which display name to match for this descriptor
                string displayName = descriptor.Column.DisplayName; 

                // if we have a controlling column, use its display name instead 
                if (descriptor.Column.ControllingColumn != null) 
                {
                    displayName = descriptor.Column.ControllingColumn.DisplayName; 
                }

                object value;
                if (propertiesFromViewState.TryGetValue(displayName, out value)) 
                {
                    // get all changed ReferencePropertyDescriptor from ViewState 
                    EntityDataSourceReferenceKeyColumn referenceColumn = descriptor.Column as EntityDataSourceReferenceKeyColumn; 

                    // convert the value as needed 
                    object adjustedValue = EntityDataSourceUtil.ConvertType(value, descriptor.PropertyType, descriptor.DisplayName);

                    if (null != referenceColumn)
                    { 
                        referenceList.Add(new KeyValuePair(
                                referenceColumn, adjustedValue)); 
                        continue; 
                    }
 
                    if (overwriteSameValue || adjustedValue != descriptor.GetValue(this))
                    {
                        if (EntityDataSourceUtil.NullCanBeAssignedTo(descriptor.PropertyType) || null != adjustedValue)
                        { 
                            try
                            { 
                                descriptor.SetValue(this, adjustedValue); 
                            }
                            catch (Exception e) 
                            {
                                // The property descriptor uses reflection to set the property. Therefore, the inner exception contains the actual message.
                                Exception exceptionToThrow = e;
                                if (e.InnerException != null) 
                                {
                                    exceptionToThrow = e.InnerException; 
                                } 
                                if (null == propertySettingExceptionsCaught)
                                { 
                                    propertySettingExceptionsCaught = new Dictionary();
                                }
                                propertySettingExceptionsCaught.Add(descriptor.DisplayName, exceptionToThrow);
                            } 
                        }
                    } 
                } 
            }
 
            // aggregate setting for EntityKey
            SetEntityKeyProperties(referenceList, overwriteSameValue);
        }
 
        private void SetEntityKeyProperties(
            List> referenceList, bool overwriteSameValue) 
        { 
            EntityDataSourceUtil.CheckArgumentNull(referenceList, "referenceList");
 
            var groups = referenceList.GroupBy(r => r.Key.Group);

            foreach (var group in groups)
            { 
                Dictionary partialKeys = new Dictionary();
 
                foreach (KeyValuePair reference in group) 
                {
                    // convert the value as needed 
                    EntityDataSourceReferenceKeyColumn column = reference.Key;
                    object keyValue = reference.Value;

                    if (null == keyValue) 
                    {
                        partialKeys = null; 
                        break; 
                    }
 
                    partialKeys.Add(column.KeyMember.Name, keyValue);
                }

                // we only set the entitykey for once, although there might be more than one 
                // properties descriptor associated with the same entitykey
                group.Key.SetKeyValues(this, partialKeys); 
            } 
        }
    } 
}

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

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