Migrating to WebClientPrint 3.0 for ASP.NET MVC & WebForms

Product WebClientPrint for ASP.NET Published 11/26/2016 Updated 11/26/2016 Author

Overview

Due to some new features and customers requests, the brand new WebClientPrint 3.0 for ASP.NET is not backwards compatible with older versions. Please use this article as a general guide to upgrading your server-side code to v3.0

In this article:

A WCPP Client phasing out support for some very old Windows versions

Starting with v3.0, the WCPP Client Utility will not longer support Windows 98, Windows 2000, and Windows ME. So if your client machines are running any of these Windows versions, then you must not migrate to v3.0

B WCP.AXD HTTP Handler

v2.0 requires the following entry in the web.config file of your website:


<system.web>
...
   <httpHandlers>
...   
      <add verb="*" path="wcp.axd" type="Neodynamic.SDK.Web.WebClientPrint, Neodynamic.SDK.WebClientPrint"/>
...   
   </httpHandlers>
...
</system.web>

<system.webServer>
...   
   <handlers>
...
      <add name="WCP" verb="*" path="wcp.axd" type="Neodynamic.SDK.Web.WebClientPrint, Neodynamic.SDK.WebClientPrint"/>
...
   </handlers>
...
</system.webServer>

Starting with v3.0, this entry is no longer needed and these are the steps to follow up for migrating:

B. 1. REMOVE these entries from your web.config file

B. 2. v3.0 requires you to create a WebClientPrint API file which will be a Controller class in MVC and a Generic Handler ASHX file in WebForms

Create a new Controller and name it WebClientPrintAPIController and then copy/paste the following code:

C#


public class WebClientPrintAPIController : Controller
{

    //*********************************
    // IMPORTANT NOTE 
    // In this sample we store users related stuff (like
    // the list of printers and whether they have the WCPP 
    // client utility installed) in the Application cache
    // object part of ASP.NET BUT you can change it to 
    // another different storage (like a DB or file server)!
    // which will be required in Load Balacing scenarios
    //*********************************

    [AllowAnonymous]
    public void ProcessRequest()
    {
        //get session ID
        string sessionID = (HttpContext.Request["sid"] != null ? HttpContext.Request["sid"] : null);

        //get Query String
        string queryString = HttpContext.Request.Url.Query;

        try
        {
            //Determine and get the Type of Request 
            RequestType prType = WebClientPrint.GetProcessRequestType(queryString);

            if (prType == RequestType.GenPrintScript ||
                prType == RequestType.GenWcppDetectScript)
            {
                //Let WebClientPrint to generate the requested script
                byte[] script = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Request.Url.Scheme), queryString);

                HttpContext.Response.ContentType = "text/javascript";
                HttpContext.Response.BinaryWrite(script);
                HttpContext.Response.End();
            }
            else if (prType == RequestType.ClientSetWcppVersion)
            {
                //This request is a ping from the WCPP utility
                //so store the session ID indicating it has the WCPP installed
                //also store the WCPP Version if available
                string wcppVersion = HttpContext.Request["wcppVer"];
                if (string.IsNullOrEmpty(wcppVersion))
                    wcppVersion = "1.0.0.0";

                HttpContext.Application.Set(sessionID + "wcppInstalled", wcppVersion);
            }
            else if (prType == RequestType.ClientSetInstalledPrinters)
            {
                //WCPP Utility is sending the installed printers at client side
                //so store this info with the specified session ID
                string printers = HttpContext.Request["printers"];
                if (string.IsNullOrEmpty(printers) == false)
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));

                HttpContext.Application.Set(sessionID + "printers", printers);

            }
            else if (prType == RequestType.ClientGetWcppVersion)
            {
                //return the WCPP version for the specified sid if any
                bool sidWcppVersion = (HttpContext.Application.Get(sessionID + "wcppInstalled") != null);

                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidWcppVersion ? HttpContext.Application.Get(sessionID + "wcppInstalled") : ""));
                HttpContext.Response.End();

            }
            else if (prType == RequestType.ClientGetInstalledPrinters)
            {
                //return the installed printers for the specified sid if any
                bool sidHasPrinters = (HttpContext.Application.Get(sessionID + "printers") != null);

                HttpContext.Response.ContentType = "text/plain";
                HttpContext.Response.Write((sidHasPrinters ? HttpContext.Application.Get(sessionID + "printers") : ""));
                HttpContext.Response.End();
            }


        }
        catch (Exception ex)
        {
            HttpContext.Response.StatusCode = 500;
            HttpContext.Response.ContentType = "text/plain";
            HttpContext.Response.Write(ex.Message + " - StackTrace: " + ex.StackTrace);
            HttpContext.Response.End();
        }

            
    }
}

VB


Public Class WebClientPrintAPIController
    Inherits Controller

    
    '*********************************
    ' IMPORTANT NOTE 
    ' In this sample we store users related stuff (like
    ' the list of printers and whether they have the WCPP 
    ' client utility installed) in the Application cache
    ' object part of ASP.NET BUT you can change it to 
    ' another different storage (like a DB or file server)!
    ' which will be required in Load Balacing scenarios
    '*********************************


    <AllowAnonymous>
    Public Sub ProcessRequest()
        'get session ID
        Dim sessionID As String = (If(HttpContext.Request("sid") IsNot Nothing, HttpContext.Request("sid"), Nothing))

        'get Query String
        Dim queryString As String = HttpContext.Request.Url.Query

        Try
            'Determine and get the Type of Request 
            Dim prType As RequestType = WebClientPrint.GetProcessRequestType(queryString)

            If prType = RequestType.GenPrintScript OrElse prType = RequestType.GenWcppDetectScript Then
                'Let WebClientPrint to generate the requested script
                Dim script As Byte() = WebClientPrint.GenerateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", Nothing, HttpContext.Request.Url.Scheme), queryString)

                HttpContext.Response.ContentType = "text/javascript"
                HttpContext.Response.BinaryWrite(script)
                HttpContext.Response.End()

            ElseIf prType = RequestType.ClientSetWcppVersion Then
                'This request is a ping from the WCPP utility
                'so store the session ID indicating it has the WCPP installed
                'also store the WCPP Version if available
                Dim wcppVersion As String = HttpContext.Request("wcppVer")
                If String.IsNullOrEmpty(wcppVersion) Then
                    wcppVersion = "1.0.0.0"
                End If

                HttpContext.Application.Set(sessionID & "wcppInstalled", wcppVersion)

            ElseIf prType = RequestType.ClientSetInstalledPrinters Then
                'WCPP Utility is sending the installed printers at client side
                'so store this info with the specified session ID
                Dim printers As String = HttpContext.Request("printers")
                If String.IsNullOrEmpty(printers) = False Then
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers))
                End If


                HttpContext.Application.Set(sessionID & "printers", printers)

            ElseIf prType = RequestType.ClientGetWcppVersion Then
                'return the WCPP version for the specified sid if any
                Dim sidWcppVersion As Boolean = (HttpContext.Application(sessionID & "wcppInstalled") IsNot Nothing)

                HttpContext.Response.ContentType = "text/plain"
                If (sidWcppVersion) Then
                    HttpContext.Response.Write(HttpContext.Application(sessionID & "wcppInstalled").ToString())
                End If
                HttpContext.Response.End()

            ElseIf prType = RequestType.ClientGetInstalledPrinters Then
                'return the installed printers for the specified sid if any
                Dim sidHasPrinters As Boolean = (HttpContext.Application(sessionID & "printers") IsNot Nothing)

                HttpContext.Response.ContentType = "text/plain"
                If (sidHasPrinters) Then
                    HttpContext.Response.Write(HttpContext.Application(sessionID & "printers").ToString())
                End If
                HttpContext.Response.End()

            End If
        Catch ex As Exception
            HttpContext.Response.StatusCode = 500
            HttpContext.Response.ContentType = "text/plain"
            HttpContext.Response.Write(ex.Message + " - StackTrace: " + ex.StackTrace)
            HttpContext.Response.End()
        End Try


    End Sub

End Class

Create a new Generic Handler and name it WebClientPrintAPI and then copy/paste the following code:

C#


public class WebClientPrintAPI : IHttpHandler {

    //*********************************
    // IMPORTANT NOTE 
    // In this sample we store users related stuff (like
    // the list of printers and whether they have the WCPP 
    // client utility installed) in the Application cache
    // object part of ASP.NET BUT you can change it to 
    // another different storage (like a DB or file server)!
    // which will be required in Load Balacing scenarios
    //*********************************

    public void ProcessRequest (HttpContext context) {
        //get session ID
        string sessionID = (context.Request["sid"] != null) ? context.Request["sid"].ToString() : null;

        //get Query String
        string queryString = context.Request.Url.Query;

        try
        {
            //Determine and get the Type of Request 
            RequestType prType = WebClientPrint.GetProcessRequestType(queryString);

            if (prType == RequestType.GenPrintScript ||
                prType == RequestType.GenWcppDetectScript)
            {
                //Let WebClientPrint to generate the requested script
                byte[] script = WebClientPrint.GenerateScript(context.Request.Url.AbsoluteUri.Replace(queryString, ""), queryString);

                context.Response.ContentType = "text/javascript";
                context.Response.BinaryWrite(script);
            }
            else if (prType == RequestType.ClientSetWcppVersion)
            {
                //This request is a ping from the WCPP utility
                //so store the session ID indicating this user has the WCPP installed
                //also store the WCPP Version if available
                string wcppVersion = context.Request["wcppVer"];
                if (string.IsNullOrEmpty(wcppVersion))
                    wcppVersion = "1.0.0.0";

                context.Application.Set(sessionID + "wcppInstalled", wcppVersion);
            }
            else if (prType == RequestType.ClientSetInstalledPrinters)
            {
                //WCPP Utility is sending the installed printers at client side
                //so store this info with the specified session ID
                string printers = context.Request["printers"];
                if (string.IsNullOrEmpty(printers) == false)
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers));

                context.Application.Set(sessionID + "printers", printers);

            }
            else if (prType == RequestType.ClientGetWcppVersion)
            {
                //return the WCPP version for the specified Session ID (sid) if any
                bool sidWcppVersion = (context.Application[sessionID + "wcppInstalled"] != null);

                context.Response.ContentType = "text/plain";
                context.Response.Write(sidWcppVersion ? context.Application[sessionID + "wcppInstalled"] : "");

            }
            else if (prType == RequestType.ClientGetInstalledPrinters)
            {
                //return the installed printers for the specified Session ID (sid) if any
                bool sidHasPrinters = (context.Application[sessionID + "printers"] != null);

                context.Response.ContentType = "text/plain";
                context.Response.Write(sidHasPrinters ? context.Application[sessionID + "printers"] : "");

            }


        }
        catch (Exception ex)
        {
            context.Response.StatusCode = 500;
            context.Response.ContentType = "text/plain";
            context.Response.Write(ex.Message + " - " + ex.StackTrace);
        }



    }

    public bool IsReusable {
        get {
            return false;
        }
    }

}

VB


Public Class WebClientPrintAPI : Implements IHttpHandler

    '*********************************
    ' IMPORTANT NOTE 
    ' In this sample we store users related stuff (like
    ' the list of printers and whether they have the WCPP 
    ' client utility installed) in the Application cache
    ' object part of ASP.NET BUT you can change it to 
    ' another different storage (like a DB or file server)!
    ' which will be required in Load Balacing scenarios
    '*********************************

    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
        'get session ID
        Dim sessionID As String = ""
        If (context.Request("sid") IsNot Nothing) Then
            sessionID = context.Request("sid")
        End If

        'get Query String
        Dim queryString As String = context.Request.Url.Query

        Try
            'Determine and get the Type of Request 
            Dim prType As RequestType = WebClientPrint.GetProcessRequestType(queryString)

            If prType = RequestType.GenPrintScript OrElse prType = RequestType.GenWcppDetectScript Then
                'Let WebClientPrint to generate the requested script
                Dim script As Byte() = WebClientPrint.GenerateScript(context.Request.Url.AbsoluteUri.Replace(queryString, ""), queryString)

                context.Response.ContentType = "text/javascript"
                context.Response.BinaryWrite(script)
            ElseIf prType = RequestType.ClientSetWcppVersion Then
                'This request is a ping from the WCPP utility
                'so store the session ID indicating this user has the WCPP installed
                'also store the WCPP Version if available
                Dim wcppVersion As String = context.Request("wcppVer")
                If String.IsNullOrEmpty(wcppVersion) Then
                    wcppVersion = "1.0.0.0"
                End If

                context.Application.Set(sessionID & "wcppInstalled", wcppVersion)
            ElseIf prType = RequestType.ClientSetInstalledPrinters Then
                'WCPP Utility is sending the installed printers at client side
                'so store this info with the specified session ID
                Dim printers As String = context.Request("printers")
                If Not String.IsNullOrEmpty(printers) Then
                    printers = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(printers))
                End If

                context.Application.Set(sessionID & "printers", printers)

            ElseIf prType = RequestType.ClientGetWcppVersion Then
                'return the WCPP version for the specified Session ID (sid) if any
                Dim sidWcppVersion As Boolean = (context.Application(sessionID & "wcppInstalled") IsNot Nothing)

                context.Response.ContentType = "text/plain"
                If (sidWcppVersion) Then
                    context.Response.Write(context.Application(sessionID & "wcppInstalled").ToString())
                End If

            ElseIf prType = RequestType.ClientGetInstalledPrinters Then
                'return the installed printers for the specified Session ID (sid) if any
                Dim sidHasPrinters As Boolean = (context.Application(sessionID & "printers") IsNot Nothing)

                context.Response.ContentType = "text/plain"

                If (sidHasPrinters) Then
                    context.Response.Write(context.Application(sessionID & "printers").ToString())
                End If

            End If
        Catch ex As Exception
            context.Response.StatusCode = 500
            context.Response.ContentType = "text/plain"
            context.Response.Write(ex.Message + " - " + ex.StackTrace)
        End Try



    End Sub


    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            Return False
        End Get
    End Property

End Class

C WCPP Detection Stuff

C. 1. METATAG for Internet Explorer

v2.0 requires the following meta tag in the HEAD section of your webpage. 


Neodynamic.SDK.Web.WebClientPrint.GetWcppDetectionMetaTag();

Starting with v3.0, this code is no longer needed so you should REMOVE this from your View or WebForm

C. 2. WCPP Detection Script

v2.0 requires the following code for generating the script code 


Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript();

Starting with v3.0, this must be replaced by the following code: 


@* WCPP detection script *@

@Html.Raw(Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Current.Request.Url.Scheme), HttpContext.Current.Session.SessionID))


<%-- WCPP detection script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateWcppDetectionScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Session.SessionID)%>

D Registering the WebClientPrint Script code generation

v2.0 requires the following code for generating the script which will allow you to print 


Neodynamic.SDK.Web.WebClientPrint.CreateScript();

Starting with v3.0, this new code will be required:

IMPORTANT NOTE: The first param of the brand new CreateScript method must be the ABSOLUTE URL to the WebClientPrintAPI (Controller or Generic Handler) you created before; the second param is the ABSOLUTE URL to the Controller-Action or Generic Handler where you create the ClientPrintJob! Last third param is the Session ID


@* Register the WebClientPrint script code. *@
    
@Html.Raw(Neodynamic.SDK.Web.WebClientPrint.CreateScript(Url.Action("ProcessRequest", "WebClientPrintAPI", null, HttpContext.Current.Request.Url.Scheme), Url.Action("PrintCommands", "DemoPrintCommands", null, HttpContext.Current.Request.Url.Scheme), HttpContext.Current.Session.SessionID)))


<%-- Register the WebClientPrint script code --%>

<%=Neodynamic.SDK.Web.WebClientPrint.CreateScript(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/WebClientPrintAPI.ashx", HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Host + ":" + HttpContext.Current.Request.Url.Port + "/DemoPrintCommandsHandler.ashx", HttpContext.Current.Session.SessionID)%>

E Returning the ClientPrintJob content

In v2.0 you returned the ClientPrintJob back to the client by using a code like this one: 


cpj.SendToClient(Response);

Starting with v3.0, the following code lines will be required:

C#


System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream";
System.Web.HttpContext.Current.Response.BinaryWrite(cpj.GetContent());
System.Web.HttpContext.Current.Response.End();

VB


System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream"
System.Web.HttpContext.Current.Response.BinaryWrite(cpj.GetContent())
System.Web.HttpContext.Current.Response.End()

C#


context.Response.ContentType = "application/octet-stream";
context.Response.BinaryWrite(cpj.GetContent());
context.Response.End();

VB


context.Response.ContentType = "application/octet-stream"
context.Response.BinaryWrite(cpj.GetContent())
context.Response.End()

That's all. Most of the changes in v3.0 are internal and requires you to make minor modifications in your projects which were created for v2.0

As always, do not hesitate to contact our dev team at http://neodynamic.com/support







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