购物车Demo,前端使用AngularJS,后端使用ASP.NET Web API(1)-后端

原文:
购物车Demo,前端使用AngularJS,后端使用ASP.NET Web API(1)–后端

chsakell分享了前端使用AngularJS,后端使用ASP.NET Web API的购物车案例，非常精彩，这里这里记录下对此项目的理解。

文章：
http://chsakell.com/2015/01/31/angularjs-feat-web-api/
http://chsakell.com/2015/03/07/angularjs-feat-web-api-enable-session-state/

源码：
https://github.com/chsakell/webapiangularjssecurity

本系列共三篇，本篇是第一篇。

购物车Demo,前端使用AngularJS,后端使用ASP.NET Web API(1)–后端
 购物车Demo,前端使用AngularJS,后端使用ASP.NET Web API(2)–前端，以及前后端Session
购物车Demo,前端使用AngularJS,后端使用ASP.NET Web API(3)–Idetity,OWIN前后端验证

■ 配置EF

首先搞清模型之间的关系：

public class Gadget
{
    public int GadgetID{
   get;set;}
    ...
    
    public int CategoryID{
   get;set;}
    public Category Category{
   get;set;}
}

public class Category
{
    public int CategoryID{
   get;set;}
    ...
    public List<Gadget> Gadgets{
   get;set;}
}


public class Order
{
    public int OrderID{
   get;set;}
    ...
    public List<Gadget> Gadgets{
   get;set;}
}

public class GadgetOrder
{
    public int GadgetOrderID{
   get;set;}
    
    public int OrderID{
   get;set;}
    public Order Order{
   get;set;}
    
    public int GadgetID{
   get;set;}
    public Gadget Gadget{
   get;set;}
}

以上，Category和Gadget是1对多的关系，GadgetOrder是Order和Gadget的中间表。

接着需要通过EF Fluent API来配置领域，需要实现EntityTypeConfiguration<TModel>这个基类。比如：

public class OrderConfiguration : EntityTypeConfiguration<Order>
{
    public OrderConfiguration()
    {
        Ignore(o => o.Gadgets);
    }
}

然后就配置上下文，继承DbContext这个基类。

public class StoreContext : DbContext
{
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        ...
        modelBuilder.Configurations.Add(new OrderConfiguration());
    }
    
    public DbSet<Order> Orders{
   get;set;}
    ...
}

我们还希望在生成数据库的时候生成一些种子数据，需要继承DropCreateDatabaseIfModelChanges<TContext>这个泛型类。

public class StoreInitializer : DropCreateDatabaseIfModelChanges<StoreContext>
{
    protected override void Seed(StoreContext context)
    {
        try
        {
            GetCategoreis().ForEach(c => context.Categories.Add(c));
            ...
        }
        catch(Exception ex)
        {
            Debug.WriteLine(ex.Message);
        }
    }
    
    private static List<Category> GetCategories()
    {
        ...
    }
}

如何调用数据库种子数据的类StoreInitializer呢？有一种方法使在项目全局文件中配置。(还有一种方法使在DbContext的构造函数中配置，还有一种在数据库迁移文件中配置，etc.)

void Application_Start(object sender, EventArgs e)
{
    Database.SetInitializer(new StoreIntializer());
}

最后，关于EF的配置部分，需要在Web.config中配置，大致如下：

<connectionStrings>
    <add name="ProductServiceContext" connectionString="Data Source=.;User=someusername;Password=somepassword;Initial Catalog=MyProductService;Integrated Security=True" providerName="System.Data.SqlClient"/>
</connectionStrings>

■ CategoriesController

先俯瞰。

public class CategoriesController : ApiController
{
    private StoreContext db = new SotoreContext();
    
    ...
    
    private bool CategoryExists(int id)
    {
        return db.Categories.Count(g => g.CategoryID=id) > 0;
    }
    
    protected override void Dispose(boo disposing)
    {
        if(disposing)
        {
            db.Dispose();
        }
        base.Dispose(disposing);
    }
}

再细节。

/GET api/Categories
public IQueryable<Category> GetCategories()
{
    return db.Categories;
}

//GET api/Categories/5
[ResponseType(typeof(Category))]
public async Task<IHttpActionResult> GetCategory(int id)
{
    Category category = await db.Categories.FindAsync(id);
    if(category == null)
    {
        return NotFound();
    }
    return Ok(category);
}

//put api/Categories/5
[ResponseType(typeof(void))]
public async Task<IHttpActionResult> PutCategory(int id, Category category)
{
    if(!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    
    if(id != category.CategoryID)
    {
        return BadRequest();
    }
    
    db.Entry(category).State = EntityState.Modified;
    
    try
    {
        await db.SavheChangesAsync();
    }
    catch(DbUpdateConcurrencyException)
    {
        if(!CategoryExists(id))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }
    return StatusCode(HttpStatusCOde.NoContet);
}

//post api/Categories
[ResponseType(typeof(Category))]
public async Task<IHttpActionResult> PostCategory(Category category)
{
    if(!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    
    db.Categories.Add(category);
    await db.SaveChangesAsync();
    
    //返回到指定的路由
    return CreatedAtRoute("DefaultApi", new {id = category.CategoryID}, category);
}

//delete api/Categoreis/5
[ResponseType(typeof(Category))]
public async Task<IHttpActionResult> DeleteCategory(int id)
{
    Category category = await db.Categories.FindAsync(id);
    if(category == null)
    {
        return NotFound();
    }
    
    db.Categories.Remove(category);
    await db.SaveChangesAsync();
    return Ok(category);
}

■ GadgetsController

先俯瞰。

public class GadgetsController : ApiController
{
    private StoreContext db = new StoreContext();
    
    protected override void Dispose(bool disposing)
    {
        if(disposing)
        {
            db.Dispose();
        }
        
        base.Dispose(disposing);
    }
    
    private bool GadgetExists(int id)
    {
        return db.Gadgets.Count(g => g.GadgetID == ID) > 0;
    }
}

再细节。

//get api/Gadgets
public IQueryable<Gadget> GetGadgets()
{
    return db.Gadgets;
}

//get api/Gadgets/5
[ResponseType(typeof(Gadgets))]
public async Task<IHttpActionResult> GetGadget(int id)
{
    Gadget gadget = await db.Gadgets.FindAsync(id);
    if(gadget == null)
    {
        return NotFound();
    }
    return Ok(gadget);
}

//put api/Gadgets/5
[ResponseType(typeof(void))]
public async Task<IHttpActionResult> PutGadget(int id, Gadget gadget)
{
    if(!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    
    if(d != gadget.GadgetID)
    {
        return BadRequest();
    }
    
    db.Entry(gadget).State = EntityState.Modified;
    
    try
    {
        await db.SaveChangesAsync();
    }
    catch(DbUpdateConcurrencyException)
    {
        if(!GadgetExists(id))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }
}

//post api/Gadgets
[ResposneType(typeof(Gadget))]
public async Task<IHttpActionResult> PostGadget(Gadget gadget)
{
    if(!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    db.Gadgets.Add(gadget);
    await db.SaveChangesAsync();
    
    return CreatedAtRoute("DefaultApi", new {id=gadget.GadgetID}, gadget)
}

//delete api/Gadgets/5
[ResponseType(typeof(Gadget))]
public async Task<IHttpActionResult> DeleteGadget(int id)
{
    Gadget gadget = await db.Gadgets.FindAsync(id);
    if(gadget == null)
    {   
          return NotFound();
    }
    db.Gadgets.Remove(gadget);
    await db.SaveChangesAsync();
    return Ok(gadget);
}

■ OrdersController

firstly overview.

public class OrdersController : ApiController
{
    private StoreContext db = new StoreContext();
    
    protected override void Dispose(bool dispoing)
    {
        if(disposing)
        {
            db.Dispose();
        }
        base.Dispose(disposing);
    }
    
    private bool OrderExists(int id)
    {
        return db.Orders.Count(g => g.OrderID == id) > 0;
    }
}

then details.

// get api/Orders
public IQueryable<Order> GetOrders()
{
    return db.Orders;
}

//get api/Orders/5
[ResponseType(typeof(Order))]
public async Task<IHttpActionResult> GetOrder(int id)
{
    Order order = await db.Orders.FindAsync(id);
    if(order == null)
    {
        return NotFound();
    }
    return Ok(order);
}

//put api/Orders/5
[ResponseType(typeof(void))]
public async Task<IHttpActionResult> PutOrder(int id, Order order)
{
    if(!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    
    if(id != order.OrderID)
    {
        return BadRequest();
    }
    
    db.Entry(order).State = EntityState.Modified;
    
    try
    {
        await db.SaveChangesAsync();
    }
    catch(DbUpdateConcurrecyException)
    {
        if(!OrderExists(id))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }
    return StatusCode(HttpStatusCOde.NoContet);
}

//post api/Orders
[RequestType(typeof(Order))]
public async Task<IHttpActionResult> PostOrder(Order order)
{
    if(!ModelState.IsValid)
    {
        reuturn BadRequest(ModelState);
    }
    try
    {
        db.Orders.Add(order);
        foreach(Gadget gadget in order.Gadgets)
        {
            db.GadgetOrders.Add(new GadgetOrder{
                OrderID = order.OrderID,
                GadgetID = gadget.GadgetID
            })
        }
        
        await db.SaveChangesAsync();
    }
    catch(Exception ex)
    {
        return BadRequest(ex.Message);
    }
    return CreatedAtRoutne("Default", new {controller = "Home", action="viewOrder", id = order.orderID}, order);
}


//delete api/Orders/5
[ResponseType(typeof(Order))]
public async Task<IHttpActionResult> DeleteOrder(int id)
{
    Order order = await db.Orders.FindAsync(id);
    if(order == null)
    {
        return NotFound();
    }
    
    db.Orders.Remoe(order);
    await db.SaveChangesAsync();
    return Ok(order);
}