Chapter08_list8-34

これまでのプロジェクトにWeb API を実装する

1. Web API 2.2をインストール

2. WebApiConfig.vbの登録先

3. リレーショナルシップを必要とするデータはJSON形式に受け入れられないため、新規モデルの追加

 1.Web API 2.2をインストール／System.Web.Httpを参照設定すること

これによりApiControllerが使用可能となる

Controllerの名前空間

System.Web.Mvc.Controller

System.Web.Http.ApiController

リスト8-34

※ArticleApiについては、この項最後

Imports System.Collections.Generic

Imports System.Linq

Imports System.Web.Http

Namespace Controllers

    Public Class ArticlesApiController    'ArticlesControllerではクラス名がバッティングするので

        Inherits ApiController

        Private db As New MvcViewContext

        Function GetArticlesByCategory(ByVal id As CategoryEnum) As IEnumerable(Of ArticleApi)

            Dim articles = db.Articles.Where(Function(a) a.Category = id).OrderBy(Function(a) a.Published) _

                                    .Select(Function(a) New ArticleApi With {.Url = a.Url,

                                                                                                             .Title = a.Title,

                                                                                                             .Category = a.Category,

                                                                                                             .Description = a.Description,

                                                                                                             .Viewcount = a.Viewcount,

                                                                                                             .Published = a.Published,

                                                                                                             .Released = a.Released,

                                                                                                             .Timestamp = a.Timestamp})

            Return articles

        End Function

    End Class

End Namespace

2.WebApiConfig.vbの登録先

リスト8-35

Imports System.Web.Routing

Imports System.Net

Imports System.Web.Http

Module WebApiConfig

    Public Sub Register(ByVal config As HttpConfiguration)

        '以下インテリセンスが働かないときがあった

        config.MapHttpAttributeRoutes()

        config.Routes.MapHttpRoute(

                name:="DefaultApi",

                routeTemplate:="api/{controller}/{id}",

                defaults:=New With {.id = RouteParameter.Optional})

    End Sub

End Module

Global.asax.vbに太字部分を追加

    Protected Sub Application_Start()

        AreaRegistration.RegisterAllAreas()

        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters)

        GlobalConfiguration.Configure(AddressOf WebApiConfig.Register)

        RouteConfig.RegisterRoutes(RouteTable.Routes)

        BundleConfig.RegisterBundles(BundleTable.Bundles)

        ・・・中略・・・

3.リレーショナルシップを必要とするデータはJSON形式に受け入れられないため、新規モデルの追加

尚、デフォルトの設定ではAdvanced REST clientから詳細なエラー情報が得られないためWeb.configに太字部分を修正または追加

・・・中略・・・

<system.web>

    <authentication mode="None" />

    <compilation debug="true" targetFramework="4.5" />

    <httpRuntime targetFramework="4.5" />

    <customErrors mode="Off" />

・・・中略・・・

  <system.webServer>

    <httpErrors errorMode="Detailed" />

    <modules>

      <remove name="FormsAuthenticationModule" />

    </modules>

・・・中略・・・

//参考

Rick Barber's Blog ／Tips for finding the real error

http://blogs.iis.net/rickbarber/working-past-500-internal-server-error     

JSON形式に対応させるためのモデル

Models/ArticlesApi.vbを追加

Public Class ArticleApi

     Public Property Id As Integer

    Public Property Url As String

    Public Property Title As String

    Public Property Category As CategoryEnum

    Public Property Description As String

    Public Property Viewcount As Integer

    Public Property Published As DateTime

    Public Property Released As Boolean

    Public Property Timestamp As Byte()

End Class

※モデルにOverridable PropertyがあるとAdvanced REST clientでエラーとなるための措置

※リレーショナルシップを必要とするデータはJSON形式に馴染まない模様