文章目录
概述
NopCommerce源码架构详解-EF相关Fluent API实现源码分析2。
内容
前面一篇文章介绍了nop中EF的Fluent API实现的一些基本类，其中最关键的就是Map映射下面我来介绍EF的Fluent API中的基本类和Map实体映射这些是在Nop中怎么调用和生效的。同样的我们先来看看核心的类图。
主要类及作用：
1、NopEngine：Nop引擎注册所有的依赖（RegisterDependencies）及启动任务（RunStartupTasks），其中包括执行所有实现接口IStartupTask的类的Execute方法。
protected virtual void RunStartupTasks()
{
var typeFinder = _containerManager.Resolve<ITypeFinder>();
var startUpTaskTypes = typeFinder.FindClassesOfType<IStartupTask>();
var startUpTasks = new List<IStartupTask>();
foreach (var startUpTaskType in startUpTaskTypes)
startUpTasks.Add((IStartupTask)Activator.CreateInstance(startUpTaskType));
//sort
startUpTasks = startUpTasks.AsQueryable().OrderBy(st => st.Order).ToList();
foreach (var startUpTask in startUpTasks)
startUpTask.Execute();
}
public void Initialize(NopConfig config)
{
//register dependencies
RegisterDependencies(config);
//startup tasks
if (!config.IgnoreStartupTasks)
{
RunStartupTasks();
}
}
2、SqlServerDataProvider：初始化数据库连接工厂及设置DatabaseInitializer。
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.SqlClient;
using System.IO;
using System.Text;
using System.Web.Hosting;
using Nop.Core.Data;
using Nop.Data.Initializers;
namespace Nop.Data
{
public class SqlServerDataProvider : IDataProvider
{
#region Utilities
protected virtual string[] ParseCommands(string filePath, bool throwExceptionIfNonExists)
{
if (!File.Exists(filePath))
{
if (throwExceptionIfNonExists)
throw new ArgumentException(string.Format("Specified file doesn't exist - {0}", filePath));
else
return new string[0];
}
var statements = new List<string>();
using (var stream = File.OpenRead(filePath))
using (var reader = new StreamReader(stream))
{
var statement = "";
while ((statement = ReadNextStatementFromStream(reader)) != null)
{
statements.Add(statement);
}
}
return statements.ToArray();
}
protected virtual string ReadNextStatementFromStream(StreamReader reader)
{
var sb = new StringBuilder();
string lineOfText;
while (true)
{
lineOfText = reader.ReadLine();
if (lineOfText == null)
{
if (sb.Length > 0)
return sb.ToString();
else
return null;
}
if (lineOfText.TrimEnd().ToUpper() == "GO")
break;
sb.Append(lineOfText + Environment.NewLine);
}
return sb.ToString();
}
#endregion
#region Methods
/// <summary>
/// Initialize connection factory
/// </summary>
public virtual void InitConnectionFactory()
{
var connectionFactory = new SqlConnectionFactory();
//TODO fix compilation warning (below)
#pragma warning disable 0618
Database.DefaultConnectionFactory = connectionFactory;
}
/// <summary>
/// Initialize database
/// </summary>
public virtual void InitDatabase()
{
InitConnectionFactory();
SetDatabaseInitializer();
}
/// <summary>
/// Set database initializer
/// </summary>
public virtual void SetDatabaseInitializer()
{
//pass some table names to ensure that we have NopCommerce 2.X installed
var tablesToValidate = new[] { "Customer", "Discount", "Order", "Product", "ShoppingCartItem" };
//custom commands (stored proedures, indexes)
var customCommands = new List<string>();
//use webHelper.MapPath instead of HostingEnvironment.MapPath which is not available in unit tests
customCommands.AddRange(ParseCommands(HostingEnvironment.MapPath("~/App_Data/SqlServer.Indexes.sql"), false));
//use webHelper.MapPath instead of HostingEnvironment.MapPath which is not available in unit tests
customCommands.AddRange(ParseCommands(HostingEnvironment.MapPath("~/App_Data/SqlServer.StoredProcedures.sql"), false));
var initializer = new CreateTablesIfNotExist<NopObjectContext>(tablesToValidate, customCommands.ToArray());
Database.SetInitializer(initializer);
}
/// <summary>
/// A value indicating whether this data provider supports stored procedures
/// </summary>
public virtual bool StoredProceduredSupported
{
get { return true; }
}
/// <summary>
/// Gets a support database parameter object (used by stored procedures)
/// </summary>
/// <returns>Parameter</returns>
public virtual DbParameter GetParameter()
{
return new SqlParameter();
}
#endregion
}
}
3、EfStartUpTask：执行所依赖对象IDataProvider的方法SetDatabaseInitializer，EF对应数据库Provider的初始化。
using Nop.Core;
using Nop.Core.Data;
using Nop.Core.Infrastructure;
namespace Nop.Data
{
public class EfStartUpTask : IStartupTask
{
public void Execute()
{
var settings = EngineContext.Current.Resolve<DataSettings>();
if (settings != null && settings.IsValid())
{
var provider = EngineContext.Current.Resolve<IDataProvider>();
if (provider == null)
throw new NopException("No IDataProvider found");
provider.SetDatabaseInitializer();
}
}
public int Order
{
//ensure that this task is run first
get { return -1000; }
}
}
}
4、EfDataProviderManager：一个IDataProvider的工厂类，可以根据配置返回接口IDataProvider的不同实现的具体类。如：SqlServerDataProvider，SqlCeDataProvider等等。
using System;
using Nop.Core;
using Nop.Core.Data;
namespace Nop.Data
{
public partial class EfDataProviderManager : BaseDataProviderManager
{
public EfDataProviderManager(DataSettings settings):base(settings)
{
}
public override IDataProvider LoadDataProvider()
{
var providerName = Settings.DataProvider;
if (String.IsNullOrWhiteSpace(providerName))
throw new NopException("Data Settings doesn't contain a providerName");
switch (providerName.ToLowerInvariant())
{
case "sqlserver":
return new SqlServerDataProvider();
case "sqlce":
return new SqlCeDataProvider();
default:
throw new NopException(string.Format("Not supported dataprovider name: {0}", providerName));
}
}
}
}
5、NopObjectContext：这相类继承于DbContext, IDbContext通过重写OnModelCreating方法通过反射获取AppDomain下面所有的程序集，然后动态创建EntityTypeConfiguration的实例，通过EF提供的API把我们配置的所有实体Map映射加入到modelBuilder的配置中去。
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.ModelConfiguration;
using System.linq;
using System.Reflection;
using Nop.Core;
namespace Nop.Data
{
public class NopObjectContext : DbContext, IDbContext
{
#region Ctor
public NopObjectContext(string nameOrConnectionString)
: base(nameOrConnectionString)
{
}
#endregion
#region Utilities
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//获取AppDomain下面所有的程序集
var typesToRegister = Assembly.GetExecutingAssembly().GetTypes()
.Where(type => !String.IsNullOrEmpty(type.Namespace))
.Where(type => type.BaseType != null && type.BaseType.IsGenericType && type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
foreach (var type in typesToRegister)
{
//动态创建EntityTypeConfiguration的实例，并把我们配置的实体Map映射加入到modelBuilder的配置中去。
dynamic configurationInstance = Activator.CreateInstance(type);
modelBuilder.Configurations.Add(configurationInstance);
}
//...or do it manually below. For example,
//modelBuilder.Configurations.Add(new LanguageMap());
base.OnModelCreating(modelBuilder);
}
/// <summary>
/// Attach an entity to the context or return an already attached entity (if it was already attached)
/// </summary>
/// <typeparam name="TEntity">TEntity</typeparam>
/// <param name="entity">Entity</param>
/// <returns>Attached entity</returns>
protected virtual TEntity AttachEntityToContext<TEntity>(TEntity entity) where TEntity : BaseEntity, new()
{
//little hack here until Entity Framework really supports stored procedures
//otherwise, navigation properties of loaded entities are not loaded until an entity is attached to the context
var alreadyAttached = Set<TEntity>().Local.FirstOrDefault(x => x.Id == entity.Id);
if (alreadyAttached == null)
{
//attach new entity
Set<TEntity>().Attach(entity);
return entity;
}
else
{
//entity is already loaded.
return alreadyAttached;
}
}
#endregion
//...其实的一些共用方法
}
}
6、DependencyRegistrar：依赖注入相关类的注册，其中就包括了IDbContext用类NopObjectContext来注册。
Nop.Web.Framework.DependencyRegistrar : IDependencyRegistrar
public virtual void Register(ContainerBuilder builder, ITypeFinder typeFinder)
{
//....
builder.Register(x => x.Resolve<BaseDataProviderManager>().LoadDataProvider()).As<IDataProvider>().InstancePerDependency();
if (dataProviderSettings != null && dataProviderSettings.IsValid())
{
var efDataProviderManager = new EfDataProviderManager(dataSettingsManager.LoadSettings());
var dataProvider = efDataProviderManager.LoadDataProvider();
dataProvider.InitConnectionFactory();
builder.Register<IDbContext>(c => new NopObjectContext(dataProviderSettings.DataConnectionString)).InstancePerLifetimeScope();
}
else
{
builder.Register<IDbContext>(c => new NopObjectContext(dataSettingsManager.LoadSettings().DataConnectionString)).InstancePerLifetimeScope();
}
}
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