IMethodHandlerAsyncTHierarchyItemAsync Interface

IT Hit WebDAV Classes Reference

Represents HTTP method handler.

Namespace: ITHit.Server.Extensibility
Assembly: ITHit.Server (in ITHit.Server.dll) Version: 11.3.10719

Syntax

public interface IMethodHandlerAsync<THierarchyItemAsync>
where THierarchyItemAsync : IHierarchyItemBaseAsync


public interface IMethodHandlerAsync<THierarchyItemAsync>
where THierarchyItemAsync : IHierarchyItemBaseAsync

Public Interface IMethodHandlerAsync(Of THierarchyItemAsync As IHierarchyItemBaseAsync)

Public Interface IMethodHandlerAsync(Of THierarchyItemAsync As IHierarchyItemBaseAsync)

generic<typename THierarchyItemAsync>
where THierarchyItemAsync : IHierarchyItemBaseAsync
public interface class IMethodHandlerAsync

generic<typename THierarchyItemAsync>
where THierarchyItemAsync : IHierarchyItemBaseAsync
public interface class IMethodHandlerAsync

type IMethodHandlerAsync<'THierarchyItemAsync when 'THierarchyItemAsync : IHierarchyItemBaseAsync> =  interface end

type IMethodHandlerAsync<'THierarchyItemAsync when 'THierarchyItemAsync : IHierarchyItemBaseAsync> =  interface end

Type Parameters

THierarchyItemAsync: Type implements IHierarchyItemBaseAsync

The IMethodHandlerAsyncTHierarchyItemAsync type exposes the following members.

Properties

	Name	Description
	EnableInputDebugLogging	Determines whether input read by this handler shall be logged if debug logging is enabled.
	EnableOutputBuffering	Determines whether engine can buffer content to calculate content length.
	EnableOutputDebugLogging	Determines whether output produces by this handler shall be logged if debug logging is enabled.

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Methods

	Name	Description
	AppliesTo	Determines whether this method shall be enlisted in 'supported-method-set' for item.
	ProcessRequestAsync	Enables processing of HTTP Web requests by a custom handler.

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Remarks

The IT Hit Server Engine allows creating custom HTTP handlers and replacing original engine handlers. To add or replace handler call RegisterMethodHandler(String, IMethodHandlerAsyncTHierarchyItemAsync) method passing HTTP method name and object instance implementing IMethodHandlerAsyncTHierarchyItemAsync. The original handler, if any, is returned from RegisterMethodHandler(String, IMethodHandlerAsyncTHierarchyItemAsync) method.

The ProcessRequestAsync(ContextAsyncTHierarchyItemAsync, THierarchyItemAsync) method of this interface is called by the engine during RunAsync(ContextAsyncTHierarchyItemAsync) call. The hierarchy item returned from GetHierarchyItemAsync(String) is passed to ProcessRequest method as a parameter.

The handler must call BeforeResponseAsync when all update methods have been called and the handler is about to start writing response.

Examples

The code below is part of 'WebDAVServer.FileSystemStorage.AspNet' C# & VB samples provided with the SDK.

C++

Copy

internal class MyCustomGetHandler : IMethodHandlerAsync<IHierarchyItemAsync>
{
    public IMethodHandlerAsync<IHierarchyItemAsync> OriginalHandler { get; set; }

    public bool EnableOutputBuffering
    {
        get { return false; }
    }

    public bool EnableOutputDebugLogging
    {
        get { return false; }
    }

    public bool EnableInputDebugLogging
    {
        get { return false; }
    }

    private readonly string htmlPath;

    public MyCustomGetHandler(string contentRootPathFolder)
    {
        this.htmlPath = contentRootPathFolder;
    }

    public async Task ProcessRequestAsync(ContextAsync<IHierarchyItemAsync> context, IHierarchyItemAsync item)
    {
        string urlPath = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd('/').Length);

        if (item is IItemCollectionAsync)
        {
            // In case of GET requests to WebDAV folders we serve a web page to display 
            // any information about this server and how to use it.

            // Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            // makes some useful things in BeforeResponseAsync.
            await context.EnsureBeforeResponseWasCalledAsync();
            IHttpAsyncHandler page = (IHttpAsyncHandler)System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(
                "~/MyCustomHandlerPage.aspx", typeof(MyCustomHandlerPage));

            if(Type.GetType("Mono.Runtime") != null)
            {
                page.ProcessRequest(HttpContext.Current);
            }
            else
            {
                // Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                // To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                await Task.Factory.FromAsync(page.BeginProcessRequest, page.EndProcessRequest, HttpContext.Current, null);
            }
        }
        else
        {
            await OriginalHandler.ProcessRequestAsync(context, item);
        }
    }

    public bool AppliesTo(IHierarchyItemAsync item)
    {
        return item is IFolderAsync || OriginalHandler.AppliesTo(item);
    }
}

Friend Class MyCustomGetHandler
    Implements IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public Property OriginalHandler As IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public ReadOnly Property EnableOutputBuffering As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputBuffering
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableOutputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputDebugLogging
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableInputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableInputDebugLogging
        Get
            Return False
        End Get
    End Property

    Private ReadOnly htmlPath As String

    Public Sub New(contentRootPathFolder As String)
        Me.htmlPath = contentRootPathFolder
    End Sub

    Public Async Function ProcessRequestAsync(context As ContextAsync(Of IHierarchyItemAsync), item As IHierarchyItemAsync) As Task Implements IMethodHandlerAsync(Of IHierarchyItemAsync).ProcessRequestAsync
        Dim urlPath As String = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd("/"c).Length)
        If TypeOf item Is IItemCollectionAsync Then
            ' In case of GET requests to WebDAV folders we serve a web page to display 
            ' any information about this server and how to use it.
            ' Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            ' makes some useful things in BeforeResponseAsync.
            Await context.EnsureBeforeResponseWasCalledAsync()
            Dim page As IHttpAsyncHandler = CType(System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath("~/MyCustomHandlerPage.aspx", GetType(MyCustomHandlerPage)), IHttpAsyncHandler)
            If Type.GetType("Mono.Runtime") IsNot Nothing Then
                page.ProcessRequest(HttpContext.Current)
            Else
                ' Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                ' To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                Await Task.Factory.FromAsync(AddressOf page.BeginProcessRequest, AddressOf page.EndProcessRequest, HttpContext.Current, Nothing)
            End If
        Else
            Await OriginalHandler.ProcessRequestAsync(context, item)
        End If
    End Function

    Public Function AppliesTo(item As IHierarchyItemAsync) As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).AppliesTo
        Return TypeOf item Is IFolderAsync OrElse OriginalHandler.AppliesTo(item)
    End Function
End Class

Examples

The code below is part of 'CalDAVServer.SqlStorage.AspNet' C# & VB samples provided with the SDK.

C++

Copy

internal class MyCustomGetHandler : IMethodHandlerAsync<IHierarchyItemAsync>
{
    public IMethodHandlerAsync<IHierarchyItemAsync> OriginalHandler { get; set; }

    public bool EnableOutputBuffering
    {
        get { return false; }
    }

    public bool EnableOutputDebugLogging
    {
        get { return false; }
    }

    public bool EnableInputDebugLogging
    {
        get { return false; }
    }

    private readonly string htmlPath;

    public MyCustomGetHandler(string contentRootPathFolder)
    {
        this.htmlPath = contentRootPathFolder;
    }

    public async Task ProcessRequestAsync(ContextAsync<IHierarchyItemAsync> context, IHierarchyItemAsync item)
    {
        string urlPath = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd('/').Length);

        if (item is IItemCollectionAsync)
        {
            // In case of GET requests to WebDAV folders we serve a web page to display 
            // any information about this server and how to use it.

            // Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            // makes some useful things in BeforeResponseAsync.
            await context.EnsureBeforeResponseWasCalledAsync();

            // Request to iOS/OS X CalDAV/CardDAV profile.
            if (context.Request.RawUrl.EndsWith("?connect"))
            {
                await WriteProfileAsync(context, item, htmlPath);
                return;
            }
            IHttpAsyncHandler page = (IHttpAsyncHandler)System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(
                "~/MyCustomHandlerPage.aspx", typeof(MyCustomHandlerPage));

            if(Type.GetType("Mono.Runtime") != null)
            {
                page.ProcessRequest(HttpContext.Current);
            }
            else
            {
                // Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                // To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                await Task.Factory.FromAsync(page.BeginProcessRequest, page.EndProcessRequest, HttpContext.Current, null);
            }
        }
        else
        {
            await OriginalHandler.ProcessRequestAsync(context, item);
        }
    }

    public bool AppliesTo(IHierarchyItemAsync item)
    {
        return item is IFolderAsync || OriginalHandler.AppliesTo(item);
    }

    private async Task WriteProfileAsync(ContextAsync<IHierarchyItemAsync> context, IHierarchyItemBaseAsync item, string htmlPath)
    {
        string mobileconfigFileName = null;
        string decription = null;
        if (item is ICalendarFolderAsync)
        {
            mobileconfigFileName = "CalDAV.AppleProfileTemplete.mobileconfig";
            decription = (item as ICalendarFolderAsync).CalendarDescription;
        }

        decription = !string.IsNullOrEmpty(decription) ? decription : item.Name;

        string templateContent = null;
        using (TextReader reader = new StreamReader(Path.Combine(htmlPath, mobileconfigFileName)))
        {
            templateContent = await reader.ReadToEndAsync();
        }

        Uri url = new Uri(context.Request.UrlPrefix);

        string payloadUUID = item.Path.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries).Last(); // PayloadUUID

        string profile = string.Format(templateContent
            , url.Host // host name
            , item.Path // CalDAV / CardDAV Principal URL. Here we can return (await (item as ICurrentUserPrincipalAsync).GetCurrentUserPrincipalAsync()).Path if needed.
            , (context as DavContext).Identity.Name // user name
            , url.Port // port                
            , (url.Scheme == "https").ToString().ToLower() // SSL
            , decription // CardDAV / CardDAV Account Description
            , Assembly.GetAssembly(this.GetType()).GetName().Version.ToString()
            , Assembly.GetAssembly(typeof(DavEngineAsync)).GetName().Version.ToString()
            , payloadUUID
            );

        byte[] profileBytes = SignProfile(context, profile);

        context.Response.ContentType = "application/x-apple-aspen-config";
        context.Response.AddHeader("Content-Disposition", "attachment; filename=profile.mobileconfig");
        context.Response.ContentLength = profileBytes.Length;
        await context.Response.OutputStream.WriteAsync(profileBytes, 0, profileBytes.Length);
    }

    private byte[] SignProfile(ContextAsync<IHierarchyItemAsync> context, string profile)
    {
        // Here you will sign your profile with SSL certificate to avoid "Unsigned" warning on iOS and OS X.
        // For demo purposes we just return the profile content unmodified.
        return context.Engine.ContentEncoding.GetBytes(profile);
    }
}

Friend Class MyCustomGetHandler
    Implements IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public Property OriginalHandler As IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public ReadOnly Property EnableOutputBuffering As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputBuffering
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableOutputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputDebugLogging
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableInputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableInputDebugLogging
        Get
            Return False
        End Get
    End Property

    Private ReadOnly htmlPath As String

    Public Sub New(contentRootPathFolder As String)
        Me.htmlPath = contentRootPathFolder
    End Sub

    Public Async Function ProcessRequestAsync(context As ContextAsync(Of IHierarchyItemAsync), item As IHierarchyItemAsync) As Task Implements IMethodHandlerAsync(Of IHierarchyItemAsync).ProcessRequestAsync
        Dim urlPath As String = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd("/"c).Length)
        If TypeOf item Is IItemCollectionAsync Then
            ' In case of GET requests to WebDAV folders we serve a web page to display 
            ' any information about this server and how to use it.
            ' Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            ' makes some useful things in BeforeResponseAsync.
            Await context.EnsureBeforeResponseWasCalledAsync()
            ' Request to iOS/OS X CalDAV/CardDAV profile.
            If context.Request.RawUrl.EndsWith("?connect") Then
                Await WriteProfileAsync(context, item, htmlPath)
                Return
            End If

            Dim page As IHttpAsyncHandler = CType(System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath("~/MyCustomHandlerPage.aspx", GetType(MyCustomHandlerPage)), IHttpAsyncHandler)
            If Type.GetType("Mono.Runtime") IsNot Nothing Then
                page.ProcessRequest(HttpContext.Current)
            Else
                ' Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                ' To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                Await Task.Factory.FromAsync(AddressOf page.BeginProcessRequest, AddressOf page.EndProcessRequest, HttpContext.Current, Nothing)
            End If
        Else
            Await OriginalHandler.ProcessRequestAsync(context, item)
        End If
    End Function

    Public Function AppliesTo(item As IHierarchyItemAsync) As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).AppliesTo
        Return TypeOf item Is IFolderAsync OrElse OriginalHandler.AppliesTo(item)
    End Function

    Private Async Function WriteProfileAsync(context As ContextAsync(Of IHierarchyItemAsync), item As IHierarchyItemBaseAsync, htmlPath As String) As Task
        Dim mobileconfigFileName As String = Nothing
        Dim decription As String = Nothing
        If TypeOf item Is ICalendarFolderAsync Then
            mobileconfigFileName = "CalDAV.AppleProfileTemplete.mobileconfig"
            decription = TryCast(item, ICalendarFolderAsync).CalendarDescription
        End If

        decription = If(Not String.IsNullOrEmpty(decription), decription, item.Name)
        Dim templateContent As String = Nothing
        Using reader As TextReader = New StreamReader(Path.Combine(htmlPath, mobileconfigFileName))
            templateContent = Await reader.ReadToEndAsync()
        End Using

        Dim url As Uri = New Uri(context.Request.UrlPrefix)
        Dim payloadUUID As String = item.Path.Split({"/"c}, StringSplitOptions.RemoveEmptyEntries).Last()
        Dim profile As String = String.Format(templateContent,
                                             url.Host, ' host name
                                             item.Path, ' CalDAV / CardDAV Principal URL. Here we can return (await (item as ICurrentUserPrincipalAsync).GetCurrentUserPrincipalAsync()).Path if needed.
                                             TryCast(context, DavContext).Identity.Name, ' user name
                                             url.Port, ' port                
                                             (url.Scheme = "https").ToString().ToLower(), ' SSL
                                             decription, ' CardDAV / CardDAV Account Description
                                             Assembly.GetAssembly(Me.GetType()).GetName().Version.ToString(),
                                             Assembly.GetAssembly(GetType(DavEngineAsync)).GetName().Version.ToString(),
                                             payloadUUID
                                             )
        Dim profileBytes As Byte() = SignProfile(context, profile)
        context.Response.ContentType = "application/x-apple-aspen-config"
        context.Response.AddHeader("Content-Disposition", "attachment; filename=profile.mobileconfig")
        context.Response.ContentLength = profileBytes.Length
        Await context.Response.OutputStream.WriteAsync(profileBytes, 0, profileBytes.Length)
    End Function

    Private Function SignProfile(context As ContextAsync(Of IHierarchyItemAsync), profile As String) As Byte()
        ' Here you will sign your profile with SSL certificate to avoid "Unsigned" warning on iOS and OS X.
        ' For demo purposes we just return the profile content unmodified.
        Return context.Engine.ContentEncoding.GetBytes(profile)
    End Function
End Class

Examples

The code below is part of 'CardDAVServer.SqlStorage.AspNet' C# & VB samples provided with the SDK.

C++

Copy

internal class MyCustomGetHandler : IMethodHandlerAsync<IHierarchyItemAsync>
{
    public IMethodHandlerAsync<IHierarchyItemAsync> OriginalHandler { get; set; }

    public bool EnableOutputBuffering
    {
        get { return false; }
    }

    public bool EnableOutputDebugLogging
    {
        get { return false; }
    }

    public bool EnableInputDebugLogging
    {
        get { return false; }
    }

    private readonly string htmlPath;

    public MyCustomGetHandler(string contentRootPathFolder)
    {
        this.htmlPath = contentRootPathFolder;
    }

    public async Task ProcessRequestAsync(ContextAsync<IHierarchyItemAsync> context, IHierarchyItemAsync item)
    {
        string urlPath = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd('/').Length);

        if (item is IItemCollectionAsync)
        {
            // In case of GET requests to WebDAV folders we serve a web page to display 
            // any information about this server and how to use it.

            // Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            // makes some useful things in BeforeResponseAsync.
            await context.EnsureBeforeResponseWasCalledAsync();

            // Request to iOS/OS X CalDAV/CardDAV profile.
            if (context.Request.RawUrl.EndsWith("?connect"))
            {
                await WriteProfileAsync(context, item, htmlPath);
                return;
            }
            IHttpAsyncHandler page = (IHttpAsyncHandler)System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(
                "~/MyCustomHandlerPage.aspx", typeof(MyCustomHandlerPage));

            if(Type.GetType("Mono.Runtime") != null)
            {
                page.ProcessRequest(HttpContext.Current);
            }
            else
            {
                // Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                // To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                await Task.Factory.FromAsync(page.BeginProcessRequest, page.EndProcessRequest, HttpContext.Current, null);
            }
        }
        else
        {
            await OriginalHandler.ProcessRequestAsync(context, item);
        }
    }

    public bool AppliesTo(IHierarchyItemAsync item)
    {
        return item is IFolderAsync || OriginalHandler.AppliesTo(item);
    }

    private async Task WriteProfileAsync(ContextAsync<IHierarchyItemAsync> context, IHierarchyItemBaseAsync item, string htmlPath)
    {
        string mobileconfigFileName = null;
        string decription = null;
        if (item is IAddressbookFolderAsync)
        {
            mobileconfigFileName = "CardDAV.AppleProfileTemplete.mobileconfig";
            decription = (item as IAddressbookFolderAsync).AddressbookDescription;
        }

        decription = !string.IsNullOrEmpty(decription) ? decription : item.Name;

        string templateContent = null;
        using (TextReader reader = new StreamReader(Path.Combine(htmlPath, mobileconfigFileName)))
        {
            templateContent = await reader.ReadToEndAsync();
        }

        Uri url = new Uri(context.Request.UrlPrefix);

        string payloadUUID = item.Path.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries).Last(); // PayloadUUID

        string profile = string.Format(templateContent
            , url.Host // host name
            , item.Path // CalDAV / CardDAV Principal URL. Here we can return (await (item as ICurrentUserPrincipalAsync).GetCurrentUserPrincipalAsync()).Path if needed.
            , (context as DavContext).Identity.Name // user name
            , url.Port // port                
            , (url.Scheme == "https").ToString().ToLower() // SSL
            , decription // CardDAV / CardDAV Account Description
            , Assembly.GetAssembly(this.GetType()).GetName().Version.ToString()
            , Assembly.GetAssembly(typeof(DavEngineAsync)).GetName().Version.ToString()
            , payloadUUID
            );

        byte[] profileBytes = SignProfile(context, profile);

        context.Response.ContentType = "application/x-apple-aspen-config";
        context.Response.AddHeader("Content-Disposition", "attachment; filename=profile.mobileconfig");
        context.Response.ContentLength = profileBytes.Length;
        await context.Response.OutputStream.WriteAsync(profileBytes, 0, profileBytes.Length);
    }

    private byte[] SignProfile(ContextAsync<IHierarchyItemAsync> context, string profile)
    {
        // Here you will sign your profile with SSL certificate to avoid "Unsigned" warning on iOS and OS X.
        // For demo purposes we just return the profile content unmodified.
        return context.Engine.ContentEncoding.GetBytes(profile);
    }
}

Friend Class MyCustomGetHandler
    Implements IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public Property OriginalHandler As IMethodHandlerAsync(Of IHierarchyItemAsync)

    Public ReadOnly Property EnableOutputBuffering As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputBuffering
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableOutputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableOutputDebugLogging
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property EnableInputDebugLogging As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).EnableInputDebugLogging
        Get
            Return False
        End Get
    End Property

    Private ReadOnly htmlPath As String

    Public Sub New(contentRootPathFolder As String)
        Me.htmlPath = contentRootPathFolder
    End Sub

    Public Async Function ProcessRequestAsync(context As ContextAsync(Of IHierarchyItemAsync), item As IHierarchyItemAsync) As Task Implements IMethodHandlerAsync(Of IHierarchyItemAsync).ProcessRequestAsync
        Dim urlPath As String = context.Request.RawUrl.Substring(context.Request.ApplicationPath.TrimEnd("/"c).Length)
        If TypeOf item Is IItemCollectionAsync Then
            ' In case of GET requests to WebDAV folders we serve a web page to display 
            ' any information about this server and how to use it.
            ' Remember to call EnsureBeforeResponseWasCalledAsync here if your context implementation
            ' makes some useful things in BeforeResponseAsync.
            Await context.EnsureBeforeResponseWasCalledAsync()
            ' Request to iOS/OS X CalDAV/CardDAV profile.
            If context.Request.RawUrl.EndsWith("?connect") Then
                Await WriteProfileAsync(context, item, htmlPath)
                Return
            End If

            Dim page As IHttpAsyncHandler = CType(System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath("~/MyCustomHandlerPage.aspx", GetType(MyCustomHandlerPage)), IHttpAsyncHandler)
            If Type.GetType("Mono.Runtime") IsNot Nothing Then
                page.ProcessRequest(HttpContext.Current)
            Else
                ' Here we call BeginProcessRequest instead of ProcessRequest to start an async page execution and be able to call RegisterAsyncTask if required. 
                ' To call APM method (Begin/End) from TAP method (Task/async/await) the Task.FromAsync must be used.
                Await Task.Factory.FromAsync(AddressOf page.BeginProcessRequest, AddressOf page.EndProcessRequest, HttpContext.Current, Nothing)
            End If
        Else
            Await OriginalHandler.ProcessRequestAsync(context, item)
        End If
    End Function

    Public Function AppliesTo(item As IHierarchyItemAsync) As Boolean Implements IMethodHandlerAsync(Of IHierarchyItemAsync).AppliesTo
        Return TypeOf item Is IFolderAsync OrElse OriginalHandler.AppliesTo(item)
    End Function

    Private Async Function WriteProfileAsync(context As ContextAsync(Of IHierarchyItemAsync), item As IHierarchyItemBaseAsync, htmlPath As String) As Task
        Dim mobileconfigFileName As String = Nothing
        Dim decription As String = Nothing
        If TypeOf item Is IAddressbookFolderAsync Then
            mobileconfigFileName = "CardDAV.AppleProfileTemplete.mobileconfig"
            decription = TryCast(item, IAddressbookFolderAsync).AddressbookDescription
        End If

        decription = If(Not String.IsNullOrEmpty(decription), decription, item.Name)
        Dim templateContent As String = Nothing
        Using reader As TextReader = New StreamReader(Path.Combine(htmlPath, mobileconfigFileName))
            templateContent = Await reader.ReadToEndAsync()
        End Using

        Dim url As Uri = New Uri(context.Request.UrlPrefix)
        Dim payloadUUID As String = item.Path.Split({"/"c}, StringSplitOptions.RemoveEmptyEntries).Last()
        Dim profile As String = String.Format(templateContent,
                                             url.Host, ' host name
                                             item.Path, ' CalDAV / CardDAV Principal URL. Here we can return (await (item as ICurrentUserPrincipalAsync).GetCurrentUserPrincipalAsync()).Path if needed.
                                             TryCast(context, DavContext).Identity.Name, ' user name
                                             url.Port, ' port                
                                             (url.Scheme = "https").ToString().ToLower(), ' SSL
                                             decription, ' CardDAV / CardDAV Account Description
                                             Assembly.GetAssembly(Me.GetType()).GetName().Version.ToString(),
                                             Assembly.GetAssembly(GetType(DavEngineAsync)).GetName().Version.ToString(),
                                             payloadUUID
                                             )
        Dim profileBytes As Byte() = SignProfile(context, profile)
        context.Response.ContentType = "application/x-apple-aspen-config"
        context.Response.AddHeader("Content-Disposition", "attachment; filename=profile.mobileconfig")
        context.Response.ContentLength = profileBytes.Length
        Await context.Response.OutputStream.WriteAsync(profileBytes, 0, profileBytes.Length)
    End Function

    Private Function SignProfile(context As ContextAsync(Of IHierarchyItemAsync), profile As String) As Byte()
        ' Here you will sign your profile with SSL certificate to avoid "Unsigned" warning on iOS and OS X.
        ' For demo purposes we just return the profile content unmodified.
        Return context.Engine.ContentEncoding.GetBytes(profile)
    End Function
End Class

Reference

ITHit.Server.Extensibility Namespace

IMethodHandlerAsyncAddLanguageSpecificTextSet("LST6E027A6B_0?cs=&lt;|vb=(Of |cpp=&lt;|fs=&lt;'|nu=(");THierarchyItemAsyncAddLanguageSpecificTextSet("LST6E027A6B_1?cs=&gt;|vb=)|cpp=&gt;|fs=&gt;|nu=)"); Interface

Type Parameters

Reference

IMethodHandlerAsyncTHierarchyItemAsync Interface