EntityDataSourceViewSchema.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataWebControls / System / Data / WebControls / EntityDataSourceViewSchema.cs / 1458001 / EntityDataSourceViewSchema.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 
using System;
using System.Collections; 
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.Entity; 
using System.Data.Metadata.Edm;
using System.Diagnostics; 
using System.Linq; 
using System.Text;
using System.Reflection; 

namespace System.Web.UI.WebControls
{
    internal class EntityDataSourceViewSchema : DataTable 
    {
        internal EntityDataSourceViewSchema(EntityDataSourceWrapperCollection wrappers) 
        { 
            DataColumn column;
            List keys = new List(); 
            PropertyDescriptorCollection properties = wrappers.GetItemProperties(null);
            MetadataWorkspace workspace = wrappers.Context.MetadataWorkspace;
            foreach (EntityDataSourceWrapperPropertyDescriptor property in properties)
            { 
                Type propertyType = property.PropertyType;
                column = ConstructColumn(property); 
 
                column.AllowDBNull = property.Column.IsNullable;
 
                EntityDataSourcePropertyColumn propertyColumn  = property.Column as EntityDataSourcePropertyColumn;
                if (null!= propertyColumn && propertyColumn.IsKey)
                {
                    keys.Add(column); 
                }
                Columns.Add(column); 
            } 
            this.PrimaryKey = keys.ToArray();
        } 

        internal EntityDataSourceViewSchema(ITypedList typedList)
        {
            PropertyDescriptorCollection properties = typedList.GetItemProperties(null); 
            CreateColumnsFromPropDescs(properties, null);
        } 
 
        internal EntityDataSourceViewSchema(IEnumerable results)
            : this(results, null) 
        {
        }

        ///  
        /// Creates a view schema with a set of typed results and an optional set of keyName properties on those results
        ///  
        internal EntityDataSourceViewSchema(IEnumerable results, string[] keyNames) 
        {
            Type type = GetListItemType(results.GetType()); 
            PropertyInfo[] infos = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);

            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(type);
            CreateColumnsFromPropDescs(properties, keyNames); 
        }
 
        ///  
        /// Creates a set of DataTable columns from a collection of property descriptors and an optional
        /// set of key names from metadata 
        /// 
        private void CreateColumnsFromPropDescs(PropertyDescriptorCollection properties, string[] keyNames)
        {
            List keys = new List(); 
            foreach (PropertyDescriptor property in properties)
            { 
                System.ComponentModel.BrowsableAttribute attr = 
                    (System.ComponentModel.BrowsableAttribute)property.Attributes[typeof(System.ComponentModel.BrowsableAttribute)];
                if (attr.Browsable) 
                {
                    DataColumn column = ConstructColumn(property);
                    // If there are keyNames, check if this column is one of the keys
                    if (keyNames != null && keyNames.Contains(column.ColumnName)) 
                    {
                        keys.Add(column); 
                    } 
                    this.Columns.Add(column);
                } 
            }
            if (keys.Count > 0)
            {
                this.PrimaryKey = keys.ToArray(); 
            }
        } 
 
        private static DataColumn ConstructColumn(PropertyDescriptor property)
        { 
            DataColumn column = new DataColumn();
            column.ColumnName = property.Name;
            Type propertyType = property.PropertyType;
 
            if (propertyType.IsGenericType && propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
            { 
                Type[] typeArguments = propertyType.GetGenericArguments(); 
                Debug.Assert(typeArguments.Length == 1, "should only have one type argument from Nullable<> condition.");
 
                column.DataType = typeArguments[0];
                column.AllowDBNull = true;
            }
            else 
            {
                column.DataType = propertyType; 
                column.AllowDBNull = !propertyType.IsValueType; 
            }
            column.ReadOnly = property.IsReadOnly; 

            column.Unique = false;
            column.AutoIncrement = false;
            column.MaxLength = -1; 
            return column;
        } 
 
        // see System.Data.Objects.DataRecordObjectView.cs
        private static PropertyInfo GetTypedIndexer(Type type) 
        {
            PropertyInfo indexer = null;

            if (typeof(IList).IsAssignableFrom(type) || 
                typeof(ITypedList).IsAssignableFrom(type) ||
                typeof(IListSource).IsAssignableFrom(type)) 
            { 
                System.Reflection.PropertyInfo[] props = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);
 
                for (int idx = 0; idx < props.Length; idx++)
                {
                    if (props[idx].GetIndexParameters().Length > 0 && props[idx].PropertyType != typeof(object))
                    { 
                        indexer = props[idx];
                        //Prefer the standard indexer, if there is one 
                        if (indexer.Name == "Item") 
                        {
                            break; 
                        }
                    }
                }
            } 

            return indexer; 
        } 

        // see System.Data.Objects.DataRecordObjectView.cs 
        private static Type GetListItemType(Type type)
        {
            Type itemType;
 
            if (typeof(Array).IsAssignableFrom(type))
            { 
                itemType = type.GetElementType(); 
            }
            else 
            {
                PropertyInfo typedIndexer = GetTypedIndexer(type);

                if (typedIndexer != null) 
                {
                    itemType = typedIndexer.PropertyType; 
                } 
                else
                { 
                    itemType = type;
                }
            }
 
            return itemType;
        } 
 
    }
 


}

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

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