WhiteSpaceCleaner for ASP.NET

ControlBuilderExtensions.vb

Imports System.Collections
Imports System.Reflection
Imports System.Web.UI
Namespace MyNamespace

    ' This class relies on the internal implementation details of ASP.NET. Tested for ASP.NET 2.0, 3.5 , 4.0
    Public NotInheritable Class ControlBuilderExtensions
        Private Sub New()
        End Sub
        Const InstPubNonpub As BindingFlags = BindingFlags.[Public] Or BindingFlags.NonPublic Or BindingFlags.Instance

        Public Shared Function GetParentBuilder(ByVal controlBuilder As ControlBuilder) As ControlBuilder
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            Return DirectCast(controlBuilder.[GetType]().GetProperty("ParentBuilder", InstPubNonpub).GetValue(controlBuilder, Nothing), ControlBuilder)
        End Function

        Public Shared Function GetRootBuilder(ByVal controlBuilder As ControlBuilder) As ControlBuilder
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            While GetParentBuilder(controlBuilder) IsNot Nothing
                controlBuilder = GetParentBuilder(controlBuilder)
            End While

            Return controlBuilder
        End Function

        Public Shared Function GetSubBuilders(ByVal controlBuilder As ControlBuilder) As ArrayList
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            Return DirectCast(controlBuilder.[GetType]().GetProperty("SubBuilders", InstPubNonpub).GetValue(controlBuilder, Nothing), ArrayList)
        End Function

        Public Shared Function GetDefaultPropertyBuilder(ByVal controlBuilder As ControlBuilder) As ControlBuilder
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            Dim pi As PropertyInfo = Nothing
            Dim type As Type = controlBuilder.[GetType]()

            While type IsNot Nothing AndAlso (InlineAssignHelper(pi, type.GetProperty("DefaultPropertyBuilder", InstPubNonpub))) Is Nothing
                type = type.BaseType
            End While

            Return DirectCast(pi.GetValue(controlBuilder, Nothing), ControlBuilder)
        End Function

        Public Shared Function GetTemplatePropertyEntries(ByVal controlBuilder As ControlBuilder) As ArrayList
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            Dim tpes As ICollection = DirectCast(controlBuilder.[GetType]().GetProperty("TemplatePropertyEntries", InstPubNonpub).GetValue(controlBuilder, Nothing), ICollection)

            If tpes Is Nothing OrElse tpes.Count = 0 Then
                Return New ArrayList(0)
            Else
                Return DirectCast(tpes, ArrayList)
            End If
        End Function

        Public Shared Function GetComplexPropertyEntries(ByVal controlBuilder As ControlBuilder) As ArrayList
            If controlBuilder Is Nothing Then
                Throw New ArgumentNullException("controlBuilder")
            End If

            Dim cpes As ICollection = DirectCast(controlBuilder.[GetType]().GetProperty("ComplexPropertyEntries", InstPubNonpub).GetValue(controlBuilder, Nothing), ICollection)

            If cpes Is Nothing OrElse cpes.Count = 0 Then
                Return New ArrayList(0)
            Else
                Return DirectCast(cpes, ArrayList)
            End If
        End Function
        Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, ByVal value As T) As T
            target = value
            Return value
        End Function
    End Class
End Namespace

NotRestrictingParserFilter.vb

Imports System.Web.UI
Namespace MyNamespace

    Public Class NotRestrictingParserFilter
        Inherits PageParserFilter
        Public Overrides ReadOnly Property AllowCode() As Boolean
            Get
                Return True
            End Get
        End Property

        Public Overrides ReadOnly Property NumberOfControlsAllowed() As Integer
            Get
                Return Integer.MaxValue
            End Get
        End Property

        Public Overrides ReadOnly Property NumberOfDirectDependenciesAllowed() As Integer
            Get
                Return Integer.MaxValue
            End Get
        End Property

        Public Overrides ReadOnly Property TotalNumberOfDependenciesAllowed() As Integer
            Get
                Return Integer.MaxValue
            End Get
        End Property

        Public Overrides Function AllowBaseType(ByVal baseType As Type) As Boolean
            Return True
        End Function

        Public Overrides Function AllowControl(ByVal controlType As Type, ByVal builder As ControlBuilder) As Boolean
            Return True
        End Function

        Public Overrides Function AllowServerSideInclude(ByVal includeVirtualPath As String) As Boolean
            Return True
        End Function

        Public Overrides Function AllowVirtualReference(ByVal referenceVirtualPath As String, ByVal referenceType As VirtualReferenceType) As Boolean
            Return True
        End Function

        Public Overrides Function GetCompilationMode(ByVal current As CompilationMode) As CompilationMode
            Return MyBase.GetCompilationMode(current)
        End Function

        Public Overrides Function GetNoCompileUserControlType() As Type
            Return MyBase.GetNoCompileUserControlType()
        End Function

        Public Overrides Sub PreprocessDirective(ByVal directiveName As String, ByVal attributes As System.Collections.IDictionary)
            MyBase.PreprocessDirective(directiveName, attributes)
        End Sub

        Public Overrides Function ProcessCodeConstruct(ByVal codeType As CodeConstructType, ByVal code As String) As Boolean
            Return MyBase.ProcessCodeConstruct(codeType, code)
        End Function

        Public Overrides Function ProcessDataBindingAttribute(ByVal controlId As String, ByVal name As String, ByVal value As String) As Boolean
            Return MyBase.ProcessDataBindingAttribute(controlId, name, value)
        End Function

        Public Overrides Function ProcessEventHookup(ByVal controlId As String, ByVal eventName As String, ByVal handlerName As String) As Boolean
            Return MyBase.ProcessEventHookup(controlId, eventName, handlerName)
        End Function

        Public Overrides Sub ParseComplete(ByVal rootBuilder As ControlBuilder)
            MyBase.ParseComplete(rootBuilder)
        End Sub

        Protected Overrides Sub Initialize()
            MyBase.Initialize()
        End Sub
    End Class
End Namespace

WhiteSpaceCleaner.vb

Imports System.Collections
Imports System.Text.RegularExpressions
Imports System.Web
Imports System.Web.UI
Imports System.Web.Configuration

Namespace MyNamespace

    Public Enum WhiteSpaceCleaning
        None
        Clean
        CleanOnReleaseBuild
    End Enum

    Public Class WhiteSpaceCleaner
        Inherits NotRestrictingParserFilter
        Const WhiteSpaceDirectiveName As String = "whitespacecleaning"

        Private _whiteSpaceCleaning As System.Nullable(Of WhiteSpaceCleaning)

        Private Shared RegexLineBreaks As New Regex("\s*\n\s*", RegexOptions.Compiled)
        Private Shared RegexWhiteSpace As New Regex("[\t ]{2,}", RegexOptions.Compiled)

        Public Overrides Sub PreprocessDirective(ByVal directiveName As String, ByVal attributes As System.Collections.IDictionary)
            If attributes.Contains(WhiteSpaceDirectiveName) Then
                _whiteSpaceCleaning = CType([Enum].Parse(GetType(WhiteSpaceCleaning), DirectCast(attributes(WhiteSpaceDirectiveName), String)), WhiteSpaceCleaning)
                attributes.Remove(WhiteSpaceDirectiveName)
            End If

            MyBase.PreprocessDirective(directiveName, attributes)
        End Sub

        Public Overrides Sub ParseComplete(ByVal rootBuilder As ControlBuilder)
            Dim whiteSpace As WhiteSpaceCleaning = IIf(_whiteSpaceCleaning.HasValue, _whiteSpaceCleaning, WhiteSpaceCleaning.CleanOnReleaseBuild)

            If whiteSpace = WhiteSpaceCleaning.Clean OrElse (whiteSpace = WhiteSpaceCleaning.CleanOnReleaseBuild AndAlso Not IsDebuggingEnabled()) Then
                TrimStringSubBuilders(rootBuilder)
            End If

            MyBase.ParseComplete(rootBuilder)
        End Sub

        Private Shared Sub TrimStringSubBuilders(ByVal controlBuilder As ControlBuilder)
            Dim subBuilders As ArrayList = ControlBuilderExtensions.GetSubBuilders(controlBuilder)

            For i As Integer = 0 To subBuilders.Count - 1
                Dim literal As String = TryCast(subBuilders(i), String)

                If String.IsNullOrEmpty(literal) Then
                    Continue For
                End If

                subBuilders(i) = CleanWhiteSpace(literal)
            Next

            For Each subBuilder As Object In subBuilders
                If TypeOf subBuilder Is ControlBuilder Then
                    TrimStringSubBuilders(DirectCast(subBuilder, ControlBuilder))
                End If
            Next

            For Each entry As TemplatePropertyEntry In ControlBuilderExtensions.GetTemplatePropertyEntries(controlBuilder)
                TrimStringSubBuilders(entry.Builder)
            Next

            For Each entry As ComplexPropertyEntry In ControlBuilderExtensions.GetComplexPropertyEntries(controlBuilder)
                TrimStringSubBuilders(entry.Builder)
            Next

            Dim defaultPropertyBuilder As ControlBuilder = ControlBuilderExtensions.GetDefaultPropertyBuilder(controlBuilder)

            If defaultPropertyBuilder IsNot Nothing Then
                TrimStringSubBuilders(defaultPropertyBuilder)
            End If
        End Sub

        Private Shared Function CleanWhiteSpace(ByVal literal As String) As String
            literal = RegexLineBreaks.Replace(literal, vbLf)
            literal = RegexWhiteSpace.Replace(literal, " ")
            Return literal
        End Function

        Private Function IsDebuggingEnabled() As Boolean
            If HttpContext.Current IsNot Nothing Then
                Return HttpContext.Current.IsDebuggingEnabled
            End If

            Return DirectCast(WebConfigurationManager.GetSection("system.web/compilation", VirtualPath), CompilationSection).Debug
        End Function

    End Class
End Namespace

WhiteSpaceCleaner is enabled through the web.config file, like this.

<configuration>
    <system.web>
        <pages pageParserFilterType="MyNamespace.WhiteSpaceCleaner"/>
    </system.web>
</configuration>

Sorry, I don't have any additional info other than this - I put this in place in 2010 and didn't document it. I have also switched to using HTTP compression built into IIS 7 instead of the 3rd party component.