Page Template Framework for ASP.NET 1.1

Imports System
Imports System.Collections
Imports System.IO
Imports System.Text.RegularExpressions
Imports System.Xml
Imports System.Xml.Serialization

Namespace Config

    ' Represents the Page.config XML file as a .NET class
    <XmlRoot()> _
    Public Class PageConfig

        ' A constant denoting the Page.config file name
        <XmlIgnore()> _
        Public Const PageConfigFileName As String = "Page.config"

        ' A constant denoting the PageConfig Cache object key
        <XmlIgnore()> _
        Public Const PageConfigCacheKey As String = "__PAGECONFIG"

        ' A constant denoting the Page.config file path
        <XmlIgnore()> _
        Public Shared ReadOnly Property PageConfigFilePath() As String

            Get

                ' Return the default path to the Page.config file
                Return String.Format("~/{0}", PageConfig.PageConfigFileName)

            End Get

        End Property

        ' The Page Templates defined in the Page.config file
        <XmlArray(), XmlArrayItem("PageTemplate", GetType(PageTemplate))> _
        Public PageTemplates As PageTemplateCollection

        ' The Pages defined in the Page.config file
        <XmlArray(), XmlArrayItem("Page", GetType(Page))> _
        Public Pages As PageCollection

        ' Default Constructor
        Public Sub New()

            ' Create a default PageTemplateCollection
            Me.PageTemplates = New PageTemplateCollection

            ' Create a default PageCollection
            Me.Pages = New PageCollection

        End Sub

        ' Locates the first Page in the PageConfig with the specified path
        ' @pagePath: The path of the Page to locate
        ' returns: The Page found in the PageConfig instance
        Public Function FindPage(ByVal pagePath As String) As Page

            ' Create a local variable to hold the Page when found
            Dim pageFound As Page = Nothing

            ' Iterate over the Pages ArrayList
            Dim _page As Page
            For Each _page In Me.Pages

                ' Check to ensure the Page's Path is not a null value
                If (_page.Path <> Nothing) Then

                    ' Check to see if the current Page's Path matches the specified pagePath
                    If (_page.Path.Trim().ToUpper().Equals(pagePath.Trim().ToUpper())) Then

                        ' The Page was found, obtain a reference to the Page
                        pageFound = _page

                        ' Break from the loop
                        Exit For

                    End If

                ElseIf (_page.Expression <> Nothing) Then

                    ' Check to see if the current Page's Expression matches the specified pagePath
                    If (Regex.IsMatch(pagePath, _page.Expression, RegexOptions.IgnoreCase)) Then

                        ' The Page matched the Expression, obtain a reference to the Page
                        pageFound = _page

                        ' Break from the loop
                        Exit For

                    End If

                End If

            Next _page

            ' Return the found Page
            Return pageFound

        End Function

        ' Locates the first Page in the PageConfig based on the path of the specified Request
        ' @request: The Request object containing the current Page path
        ' returns: The Page found in the PageConfig instance
        Public Function FindPage(ByVal request As System.Web.HttpRequest) As Page

            ' Call the FindPage method and specify the Request's path, replacing the ApplicationPath with a tilde
            Return Me.FindPage(request.Path.ToUpper().Replace(request.ApplicationPath.ToUpper(), "~"))

        End Function

        ' Locates the specified templateName in the Page's PageTemplates collection
        ' @templateName: The template to be located
        ' returns: A reference ot the specified PageTemplate
        Public Function FindTemplate(ByVal templateName As String) As PageTemplate

            ' Create a local variable to hold the PageTemplate if found
            Dim templateFound As PageTemplate = Nothing

            ' Iterate over the templates in the PageTemplates ArrayList
            Dim template As PageTemplate
            For Each template In Me.PageTemplates

                ' Check to see if the curren PageTemplate matches the specified template
                If (template.Name.Trim().ToUpper().Equals(templateName.Trim().ToUpper())) Then

                    ' The PageTemplate was found, obtain a reference to the template
                    templateFound = template

                    ' Break from the loop
                    Exit For

                End If

            Next template

            ' Return the found PageTemplate
            Return templateFound

        End Function


        ' Locates the default PageTemplate specified for PageConfig
        ' returns: A reference to the default PageTemplate
        Public Function FindDefaultTemplate() As PageTemplate

            ' Create a local variable to hold the default PageTemplate
            Dim defaultTemplate As PageTemplate = Nothing

            ' Iterate over the templates in the PageTemplates ArrayList
            For Each template As PageTemplate In Me.PageTemplates

                ' Check to see if the current template is the default template
                If (template.IsDefault) Then

                    ' Obtain a reference to the default template
                    defaultTemplate = template

                End If

            Next

            ' Return the default PageTemplate
            Return defaultTemplate

        End Function


        ' Saves the PageConfig instance to the specified path
        ' @configFilePath: The path to which the PageConfig will be saved
        Public Sub Save(ByVal configFilePath As String)

            ' Create an XmlSerializer to save the Page.config file
            Dim xs As New XmlSerializer(GetType(PageConfig))

            ' Create an XmlTextWriter for saving the serialized XML to a file
            Dim writer As New XmlTextWriter(configFilePath, System.Text.Encoding.UTF8)

            ' Set the formatting mode for the writer
            writer.Formatting = Formatting.Indented

            ' Serialize the PageConfig into the writer
            xs.Serialize(writer, Me)

            ' Flush the writer
            writer.Flush()

            ' Close the writer
            writer.Close()

        End Sub


        ' Returns an XML string representing the serialized PageConfig
        ' returns: An XML string representing the serialized PageConfig
        Public Overrides Function ToString() As String

            ' Create an XmlSerializer to generate the Page.config XML string
            Dim xs As New XmlSerializer(GetType(PageConfig))

            ' Create a MemoryStream to serialize the instance into
            Dim ms As New MemoryStream

            ' Serialize the instance into the MemoryStream
            xs.Serialize(ms, Me)

            ' Get the XML string from the MemoryStream
            Return System.Text.Encoding.UTF8.GetString(ms.ToArray())

        End Function


        ' Deserializes the specified configuration file into a new instance 
        ' of the PageConfig class
        ' @configPath: The path to the configuration file
        ' returns: The configuration file as an instance of the PageConfig class
        Public Shared Function Load(ByVal configFilePath As String) As PageConfig

            ' Load the Page.config file into an XmlTextReader
            Dim reader As New XmlTextReader(configFilePath)

            ' Create an XmlSerializer to load the Page.config file
            Dim xs As New XmlSerializer(GetType(PageConfig))

            ' Deserialize the Page.config file into a PageConfig object
            Dim pc As PageConfig = CType(xs.Deserialize(reader), PageConfig)

            ' Close the XmlTextReader
            reader.Close()

            ' Return the deserialized instance
            Return pc

        End Function

    End Class

End Namespace