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 1Imports Microsoft.VisualBasic
 2
 3Imports System
 4Imports System.Collections.Generic
 5Imports System.Configuration
 6Imports System.Web.Configuration
 7
 8 _
 9
10
11'/<summary>
12'/ class News
13'/ Provides static functions to access News
14'/ and serves as abastraction layer between the web Page and
15'/ actual data providers
16'/</summary>
17Public Class NewsClass News
18
19    Private Shared _isInitialized As Boolean = False
20    Private Shared _provider As NewsProvider
21    Private Shared _providersSection As SmallBusinessDataProvidersSection
22
23
24    ' <summary>
25    ' Returns provider
26    ' </summary>
27    Public Shared ReadOnly Property Provider()Property Provider() As NewsProvider
28        Get
29            Initialize()
30            Return _provider
31        End Get
32    End Property
33
34
35    ' <summary>
36    ' Returns all news items
37    ' </summary>
38    Public Shared Function GetAllNews()Function GetAllNews() As List(Of NewsItem)
39        Return Provider.GetAllNews()
40    End Function 'New
41
42
43    ' <summary>
44    ' Returns a particular news item
45    ' </summary>
46    Public Shared Function GetNewsItem()Function GetNewsItem(ByVal newsItemId As String) As NewsItem
47        Return Provider.GetNewsItem(newsItemId)
48    End Function 'GetNewsItem
49
50    ' <summary>
51    ' Initializes the Provider
52    ' </summary>
53    Private Shared Sub Initialize()Sub Initialize()
54        If Not _isInitialized Then
55
56            _providersSection = ConfigurationManager.GetSection("SmallBusinessDataProviders") '
57
58            If _providersSection Is Nothing Then
59                Throw New InvalidOperationException(Messages.NewsConfigSectionNotFound)
60            End If
61
62            _provider = ProvidersHelper.InstantiateProvider(_providersSection.NewsProviders(_providersSection.NewsProviderName), GetType(NewsProvider))
63
64            If _provider Is Nothing Then
65                Throw New InvalidOperationException(Messages.NewsProviderInstantiationError)
66            End If
67
68            _isInitialized = True
69        End If
70    End Sub 'Initialize
71End Class 'News ' end class