EFDataModelProvider.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / DynamicData / DynamicData / ModelProviders / EFDataModelProvider.cs / 1305376 / EFDataModelProvider.cs
                        

                        
                            using System.Collections.Generic; 
using System.Collections.ObjectModel;
using System.Data.Metadata.Edm;
using System.Data.Objects;
using System.Diagnostics; 
using System.Globalization;
using System.Linq; 
 
namespace System.Web.DynamicData.ModelProviders {
    internal sealed class EFDataModelProvider : DataModelProvider { 
        private ReadOnlyCollection _tables;

        internal Dictionary RelationshipEndLookup { get; private set; }
        internal Dictionary TableEndLookup { get; private set; } 
        private Func ContextFactory { get; set; }
        private Dictionary _entityTypeToClrType = new Dictionary(); 
        private ObjectContext _context; 
        private ObjectItemCollection _objectSpaceItems;
 
        public EFDataModelProvider(object contextInstance, Func contextFactory) {
            ContextFactory = contextFactory;
            RelationshipEndLookup = new Dictionary();
            TableEndLookup = new Dictionary(); 

            _context = (ObjectContext)contextInstance ?? (ObjectContext)CreateContext(); 
            ContextType = _context.GetType(); 

            // get a "container" (a scope at the instance level) 
            EntityContainer container = _context.MetadataWorkspace.GetEntityContainer(_context.DefaultContainerName, DataSpace.CSpace);
            // load object space metadata
            _context.MetadataWorkspace.LoadFromAssembly(ContextType.Assembly);
            _objectSpaceItems = (ObjectItemCollection)_context.MetadataWorkspace.GetItemCollection(DataSpace.OSpace); 

            var tables = new List(); 
 
            // Create a dictionary from entity type to entity set. The entity type should be at the root of any inheritance chain.
            IDictionary entitySetLookup = container.BaseEntitySets.OfType().ToDictionary(e => e.ElementType); 

            // Create a lookup from parent entity to entity
            ILookup derivedTypesLookup = _context.MetadataWorkspace.GetItems(DataSpace.CSpace).ToLookup(e => (EntityType)e.BaseType);
 
            // Keeps track of the current entity set being processed
            EntitySet currentEntitySet = null; 
 
            // Do a DFS to get the inheritance hierarchy in order
            // i.e. Consider the hierarchy 
            // null -> Person
            // Person -> Employee, Contact
            // Employee -> SalesPerson, Programmer
            // We'll walk the children in a depth first order -> Person, Employee, SalesPerson, Programmer, Contact. 
            var objectStack = new Stack();
            // Start will null (the root of the hierarchy) 
            objectStack.Push(null); 
            while (objectStack.Any()) {
                EntityType entityType = objectStack.Pop(); 
                if (entityType != null) {
                    // Update the entity set when we are at another root type (a type without a base type).
                    if (entityType.BaseType == null) {
                        currentEntitySet = entitySetLookup[entityType]; 
                    }
 
                    var table = CreateTableProvider(currentEntitySet, entityType); 
                    tables.Add(table);
                } 

                foreach (EntityType derivedEntityType in derivedTypesLookup[entityType]) {
                    // Push the derived entity types on the stack
                    objectStack.Push(derivedEntityType); 
                }
            } 
 
            _tables = tables.AsReadOnly();
        } 

        public override object CreateContext() {
            return ContextFactory();
        } 

        public override ReadOnlyCollection Tables { 
            get { 
                return _tables;
            } 
        }

        internal Type GetClrType(EdmType entityType) {
            var result = _entityTypeToClrType[entityType]; 
            Debug.Assert(result != null, String.Format(CultureInfo.CurrentCulture, "Cannot map EdmType '{0}' to matching CLR Type", entityType));
            return result; 
        } 

        private Type GetClrType(EntityType entityType) { 
            var objectSpaceType = (EntityType)_context.MetadataWorkspace.GetObjectSpaceType(entityType);
            return _objectSpaceItems.GetClrType(objectSpaceType);
        }
 
        private TableProvider CreateTableProvider(EntitySet entitySet, EntityType entityType) {
            // Get the parent clr type 
            Type parentClrType = null; 
            EntityType parentEntityType = entityType.BaseType as EntityType;
            if (parentEntityType != null) { 
                parentClrType = GetClrType(parentEntityType);
            }

            Type rootClrType = GetClrType(entitySet.ElementType); 
            Type clrType = GetClrType(entityType);
 
            _entityTypeToClrType[entityType] = clrType; 

            // Normally, use the entity set name as the table name 
            string tableName = entitySet.Name;

            // But in inheritance scenarios where all types in the hierarchy share the same entity set,
            // we need to use the type name instead for the table name. 
            if (parentClrType != null) {
                tableName = entityType.Name; 
            } 

            EFTableProvider table = new EFTableProvider(this, entitySet, entityType, clrType, parentClrType, rootClrType, tableName); 
            TableEndLookup[entityType] = table;

            return table;
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.


                        

                        

                        
                        
                    
                    

                        
Link Menu

                        
                            Network programming in C#, Network Programming in VB.NET, Network Programming in .NET

                        

                            This book is available now!


                             Buy at Amazon US or 


                             Buy at Amazon UK