Cookies in ASP.NET

I always find myself struggling with Cookies in asp.net.

I always fail to add the cookies the right way or to remove them.
I always tend to open old projects to see how I coped then.
But most of the project are filled with different tries to get the cookie stuff to work so it doesnt help much.

There are three issues that we are dealing with

1. Adding a cookie that never expires
2. Adding a cookie that expires with a day or so
3. Removing a cookie

1 + 2. The first mistake I make is trying to add a cookie to the Request.Cookie collection which obviously doesnt work due to the fact it is a collection comming from the server.

All cookie should be added to the Response.Cookie collection.
For adding expiration you just set the Expire property on the HttpCollection before adding the cookie. For a cookie that never expires you set Expire = DateTime.MaxValue;

3. Removing a cookie is not done "just" by removing the cookie from the request cookie collection. You also need to add a new cookie with the same name as the one you want to remove and setting Expire to yesterday to Response.Cookie collection . This forces the cookie to expire the next time the client requests the page.

 HttpCookie c = new HttpCookie(CookieName, "false");  
 c.Expires = DateTime.Now.AddDays(-1);  
 Response.Cookies.Add(c);  
 Request.Cookies.Remove(CookieName);   

Very simple but a hell of a job if you forget just one of them.

Changing control names on postback

I recently spent a whole day figuring out why my UserControl continuesly displayed inline errormessages instead of the validation summary I did tell it to use.

After af lot of investigation I found out that the controls in my UserControl did have changing control names upon postback due to inserted into sitecore placeholder.

I have failed to reproduce this scenario in a controlled matter but did find a fix to the problem.

Find the control that changes name upon postback and use this implementation of the sitecore placeholder.

 public class SCPlaceholder : Sitecore.Web.UI.WebControls.Placeholder  
   {  
     private List UsedKeys = System.Web.HttpContext.Current.Items["pckeys"] as List;  
     public SCPlaceholder()  
     {  
       if (UsedKeys == null)  
       {  
         UsedKeys = new List();  
         System.Web.HttpContext.Current.Items["pckeys"] = UsedKeys;  
       }  
     }  
     protected override void AddedControl(System.Web.UI.Control control, int index)  
     {  
       Sublayout s = control as Sublayout;  
       if (s != null && s.Controls.Count == 1)  
       {  
         string name = this.Key + "_" + s.Controls[0].GetType().Name;  
         if (UsedKeys.Contains(name))  
         {  
           for (int i = 0; i < 5; i++)  
           {  
             if (!UsedKeys.Contains(name + "_" + i))  
               name += "_" + i;  
           }  
         }  
         s.ID = name + "_sub";  
         s.Controls[0].ID = name;  
         UsedKeys.Add(name);  
       }  
       base.AddedControl(control, index);  
     }  
   }   

Experiences on how to reproduce this in a safe and clean environment is appreciated.

Early vs. late binding

In the good old COM days the early vs. late binding issue was an issue that all developers should deal with. This article describes the pros and cons of the early vs. late binding issue.

This days I havnt been dealing with this issue very much all though the System.Reflection namespace has been used a lot it is not excatly the same. The reflection namespace allows us to examine assemblies for methods and properties but is done to make a system very generic and should be designed not to fail if a specific method or property is not found.

The tendency in more and more generic CMS systems and internal modules raise this issue again.
Lets have a look at some code sample

 public class MyItems  
 {  
   public Dictionary items = new Dictionary();  
   public Dictionary Items  
   {  
     get  
     {  
       return items;  
     }  
   }  
 }  
 public class MyClass  
 {  
   public void OnLoad()  
   {  
     MyItems items = new MyItems();  
     String s = Items["Item1"];  
   }  
 }  

Two classes have been made. One that contains an Items property that returns a generic dictionary with all available items and one that uses late binding when accessing the Items property. It is late binding because we dont know if the item exists and the compiler cant warn us if we make a spelling error.
Depending on how the Items property are created the application might fail if a none existing item is accessed. Other applikations might just return an empty string but this might as well result in undesired result.

A far better way, though not solving but makeing handling of these issues more simple, is to create extension methods like this.

This results in a new static class and a change in the MyClass

 public static class MyExtensionMethods  
 {  
   public static String Item1(this MyItems item)  
   {  
     if (!item.Items.ContainsKey("Item1"))  
       throw new ApplicationException("Item1 does not exists");  
     return item.Items["Item1"];  
   }  
 }  
 public class MyClass  
 {  
   public void OnLoad()  
   {  
     MyItems items = new MyItems();  
     String s = items.Item1();  
   }  
 }  

This still uses late binding but it is now done in a more controlled manner and all classes that uses MyItems and has a using MyExtensionMethods; now can use the Item1() extension.
If the Item1 for some reason should change name or some other handling should be done if the item does not exists or is empty it only needs to be done place. And if you need to change the Item1() extension name the compiler now helps you find all references.

All though this sample code does not remove the late binding it sure removes much of the complexity of it by putting it together in one place.
Of course you can wrap the MyItems class in a wrapper class that exposes Item1 as a property which will give the same result as the extension method but requires more code.
And why not use this very neat feature in the .NET 3.5 framework called ExtensionMethods?

How to Binary serialize a MailMessage for use with MessageQueue

The MailMessage object is in itself not serializeable.
The MessageQueue needs a serializeable object in order to work so as is the MailMessage is no target for the MessageQueue.

This has bothered me for a long time but finally the right project arrived with the need of Queuing MailMessages.

Almost all examples on the internet describes how to XML serialize the MailMessage but most of the times only the simple types are serialized; like To, From, Subject and Body.
What about AlternateViews and Attachments? This has been left for your imagination.

I decided to start my own SerializeableMailMessage class that should be Binary seriablizeable. Its only hard work and 500 lines of code is the result of this effort.

There is no tricky stuff in it. It is only hard work figuring out how to serialize each object in the MailMessage object.

You use it by creating a new SerializeableMailMessage() feeding it with a MailMessage object. GetMailMessage() on the SeriablizeableMailMessage object gives you the MailMessage object back.

 using System;  
 using System.Collections.Generic;  
 using System.Text;  
 using System.Text.RegularExpressions;  
 using System.Net;  
 using System.Net.Mail;  
 using System.IO;  
 using System.Net.Mime;  
 using System.Collections.Specialized;  
 namespace Netmester.Mail.Serialization  
 {  
      [Serializable]  
      internal class SerializeableLinkedResource  
      {  
           String ContentId;  
           Uri ContentLink;  
           Stream ContentStream;  
           SerializeableContentType ContentType;  
           TransferEncoding TransferEncoding;  
           internal static SerializeableLinkedResource GetSerializeableLinkedResource(LinkedResource lr)  
           {  
                if (lr == null)  
                     return null;  
                SerializeableLinkedResource slr = new SerializeableLinkedResource();  
                slr.ContentId = lr.ContentId;  
                slr.ContentLink = lr.ContentLink;  
                if (lr.ContentStream != null)  
                {  
                     byte[] bytes = new byte[lr.ContentStream.Length];  
         lr.ContentStream.Position = 0;  
                     lr.ContentStream.Read(bytes, 0, bytes.Length);  
                     slr.ContentStream = new MemoryStream(bytes);  
                }  
                slr.ContentType = SerializeableContentType.GetSerializeableContentType(lr.ContentType);  
                slr.TransferEncoding = lr.TransferEncoding;  
                return slr;  
           }  
           internal LinkedResource GetLinkedResource()  
           {  
                LinkedResource slr = new LinkedResource(ContentStream);  
                slr.ContentId = ContentId;  
                slr.ContentLink = ContentLink;  
                slr.ContentType = ContentType.GetContentType();  
                slr.TransferEncoding = TransferEncoding;  
                return slr;  
           }  
      }  
      [Serializable]  
      internal class SerializeableAlternateView  
      {  
           Uri BaseUri;  
           String ContentId;  
           Stream ContentStream;  
           SerializeableContentType ContentType;  
           List<SerializeableLinkedResource> LinkedResources = new List<SerializeableLinkedResource>();  
           TransferEncoding TransferEncoding;  
           internal static SerializeableAlternateView GetSerializeableAlternateView(AlternateView av)  
           {  
                if (av == null)  
                     return null;  
                SerializeableAlternateView sav = new SerializeableAlternateView();  
                sav.BaseUri = av.BaseUri;  
                sav.ContentId = av.ContentId;  
                if (av.ContentStream != null)  
                {  
                     byte[] bytes = new byte[av.ContentStream.Length];  
         // Reset read position  
         av.ContentStream.Position = 0;  
         av.ContentStream.Read(bytes, 0, bytes.Length);  
         sav.ContentStream = new MemoryStream(bytes);  
                }  
                sav.ContentType = SerializeableContentType.GetSerializeableContentType(av.ContentType);  
                foreach (LinkedResource lr in av.LinkedResources)  
                     sav.LinkedResources.Add(SerializeableLinkedResource.GetSerializeableLinkedResource(lr));  
                sav.TransferEncoding = av.TransferEncoding;  
                return sav;  
           }  
           internal AlternateView GetAlternateView()  
           {  
                AlternateView sav = new AlternateView(ContentStream);  
                sav.BaseUri = BaseUri;  
                sav.ContentId = ContentId;  
                sav.ContentType = ContentType.GetContentType();  
                foreach (SerializeableLinkedResource lr in LinkedResources)  
                     sav.LinkedResources.Add(lr.GetLinkedResource());  
                sav.TransferEncoding = TransferEncoding;  
                return sav;  
           }  
      }  
      [Serializable]  
      internal class SerializeableMailAddress  
      {  
           String User;  
           String Host;  
           String Address;  
           String DisplayName;  
           internal static SerializeableMailAddress GetSerializeableMailAddress(MailAddress ma)  
           {  
                if (ma == null)  
                     return null;  
                SerializeableMailAddress sma = new SerializeableMailAddress();  
                sma.User = ma.User;  
                sma.Host = ma.Host;  
                sma.Address = ma.Address;  
                sma.DisplayName = ma.DisplayName;  
                return sma;  
           }  
           internal MailAddress GetMailAddress()  
           {  
                return new MailAddress(Address, DisplayName);  
           }  
      }  
      [Serializable]  
      internal class SerializeableContentDisposition  
      {  
           DateTime CreationDate;  
           String DispositionType;  
           String FileName;  
           Boolean Inline;  
           DateTime ModificationDate;  
           SerializeableCollection Parameters;  
           DateTime ReadDate;  
           long Size;  
           internal static SerializeableContentDisposition GetSerializeableContentDisposition(System.Net.Mime.ContentDisposition cd)  
           {  
                if (cd == null)  
                     return null;  
                SerializeableContentDisposition scd = new SerializeableContentDisposition();  
                scd.CreationDate = cd.CreationDate;  
                scd.DispositionType = cd.DispositionType;  
                scd.FileName = cd.FileName;  
                scd.Inline = cd.Inline;  
                scd.ModificationDate = cd.ModificationDate;  
                scd.Parameters = SerializeableCollection.GetSerializeableCollection(cd.Parameters);  
                scd.ReadDate = cd.ReadDate;  
                scd.Size = cd.Size;  
                return scd;  
           }  
           internal void SetContentDisposition(ContentDisposition scd)  
           {  
                scd.CreationDate = CreationDate;  
                scd.DispositionType = DispositionType;  
                scd.FileName = FileName;  
                scd.Inline = Inline;  
                scd.ModificationDate = ModificationDate;  
                Parameters.SetColletion(scd.Parameters);  
                scd.ReadDate = ReadDate;  
                scd.Size = Size;  
           }  
      }  
      [Serializable]  
      internal class SerializeableContentType  
      {  
           String Boundary;  
           String CharSet;  
           String MediaType;  
           String Name;  
           SerializeableCollection Parameters;  
           internal static SerializeableContentType GetSerializeableContentType(System.Net.Mime.ContentType ct)  
           {  
                if (ct == null)  
                     return null;  
                SerializeableContentType sct = new SerializeableContentType();  
                sct.Boundary = ct.Boundary;  
                sct.CharSet = ct.CharSet;  
                sct.MediaType = ct.MediaType;  
                sct.Name = ct.Name;  
                sct.Parameters = SerializeableCollection.GetSerializeableCollection(ct.Parameters);  
                return sct;  
           }  
           internal ContentType GetContentType()  
           {  
                ContentType sct = new ContentType();  
                sct.Boundary = Boundary;  
                sct.CharSet = CharSet;  
                sct.MediaType = MediaType;  
                sct.Name = Name;  
                Parameters.SetColletion(sct.Parameters);  
                return sct;  
           }  
      }  
      [Serializable]  
      internal class SerializeableAttachment  
      {  
           String ContentId;  
           SerializeableContentDisposition ContentDisposition;  
           SerializeableContentType ContentType;  
           Stream ContentStream;  
           System.Net.Mime.TransferEncoding TransferEncoding;  
           String Name;  
           Encoding NameEncoding;  
           internal static SerializeableAttachment GetSerializeableAttachment(Attachment att)  
           {  
                if (att == null)  
                     return null;  
                SerializeableAttachment saa = new SerializeableAttachment();  
                saa.ContentId = att.ContentId;  
                saa.ContentDisposition = SerializeableContentDisposition.GetSerializeableContentDisposition(att.ContentDisposition);  
                if (att.ContentStream != null)  
                {  
                     byte[] bytes = new byte[att.ContentStream.Length];  
                  att.ContentStream.Position = 0;   
         att.ContentStream.Read(bytes, 0, bytes.Length);  
                     saa.ContentStream = new MemoryStream(bytes);  
                }  
                saa.ContentType = SerializeableContentType.GetSerializeableContentType(att.ContentType);  
                saa.Name = att.Name;  
                saa.TransferEncoding = att.TransferEncoding;  
                saa.NameEncoding = att.NameEncoding;  
                return saa;  
           }  
           internal Attachment GetAttachment()  
           {  
                Attachment saa = new Attachment(ContentStream, Name);  
                saa.ContentId = ContentId;  
                this.ContentDisposition.SetContentDisposition(saa.ContentDisposition);  
                saa.ContentType = ContentType.GetContentType();  
                saa.Name = Name;  
                saa.TransferEncoding = TransferEncoding;  
                saa.NameEncoding = NameEncoding;  
                return saa;  
           }  
      }  
      [Serializable]  
      internal class SerializeableCollection  
      {  
           Dictionary<String, String> Collection = new Dictionary<string, string>();  
           internal SerializeableCollection()  
           {  
           }  
           internal static SerializeableCollection GetSerializeableCollection(NameValueCollection col)  
           {  
                if (col == null)  
                     return null;  
                SerializeableCollection scol = new SerializeableCollection();  
                foreach (String key in col.Keys)  
                     scol.Collection.Add(key, col[key]);  
                return scol;  
           }  
           internal static SerializeableCollection GetSerializeableCollection(StringDictionary col)  
           {  
                if (col == null)  
                     return null;  
                SerializeableCollection scol = new SerializeableCollection();  
                foreach (String key in col.Keys)  
                     scol.Collection.Add(key, col[key]);  
                return scol;  
           }  
           internal void SetColletion(NameValueCollection scol)  
           {  
                foreach (String key in Collection.Keys)  
                {  
                     scol.Add(key, this.Collection[key]);  
                }  
           }  
           internal void SetColletion(StringDictionary scol)  
           {  
                foreach (String key in Collection.Keys)  
                {  
                     if (scol.ContainsKey(key))  
                          scol[key] = Collection[key];  
                     else  
                          scol.Add(key, this.Collection[key]);  
                }  
           }  
      }  
      /// <summary>  
      /// Serializeable mailmessage object  
      /// </summary>  
      [Serializable]  
      public class SerializeableMailMessage  
      {  
           Boolean IsBodyHtml { get; set; }  
           String Body { get; set; }  
           SerializeableMailAddress From { get; set; }  
           List<SerializeableMailAddress> To = new List<SerializeableMailAddress>();  
           List<SerializeableMailAddress> CC = new List<SerializeableMailAddress>();  
           List<SerializeableMailAddress> Bcc = new List<SerializeableMailAddress>();  
           SerializeableMailAddress ReplyTo { get; set; }  
           SerializeableMailAddress Sender { get; set; }  
           String Subject { get; set; }  
           List<SerializeableAttachment> Attachments = new List<SerializeableAttachment>();  
           Encoding BodyEncoding;  
           Encoding SubjectEncoding;  
           DeliveryNotificationOptions DeliveryNotificationOptions;  
           SerializeableCollection Headers;  
           MailPriority Priority;  
           List<SerializeableAlternateView> AlternateViews = new List<SerializeableAlternateView>();  
           /// <summary>  
           /// Creates a new serializeable mailmessage based on a MailMessage object  
           /// </summary>  
           /// <param name="mm"></param>  
           public SerializeableMailMessage(MailMessage mm)  
           {  
                IsBodyHtml = mm.IsBodyHtml;  
                Body = mm.Body;  
                Subject = mm.Subject;  
                From = SerializeableMailAddress.GetSerializeableMailAddress(mm.From);  
                To = new List<SerializeableMailAddress>();  
                foreach (MailAddress ma in mm.To)  
                {  
                     To.Add(SerializeableMailAddress.GetSerializeableMailAddress(ma));  
                }  
                CC = new List<SerializeableMailAddress>();  
                foreach (MailAddress ma in mm.CC)  
                {  
                     CC.Add(SerializeableMailAddress.GetSerializeableMailAddress(ma));  
                }  
                Bcc = new List<SerializeableMailAddress>();  
                foreach (MailAddress ma in mm.Bcc)  
                {  
                     Bcc.Add(SerializeableMailAddress.GetSerializeableMailAddress(ma));  
                }  
                Attachments = new List<SerializeableAttachment>();  
                foreach (Attachment att in mm.Attachments)  
                {  
                     Attachments.Add(SerializeableAttachment.GetSerializeableAttachment(att));  
                }  
                BodyEncoding = mm.BodyEncoding;  
                DeliveryNotificationOptions = mm.DeliveryNotificationOptions;  
                Headers = SerializeableCollection.GetSerializeableCollection(mm.Headers);  
                Priority = mm.Priority;  
                ReplyTo = SerializeableMailAddress.GetSerializeableMailAddress(mm.ReplyTo);  
                Sender = SerializeableMailAddress.GetSerializeableMailAddress(mm.Sender);  
                SubjectEncoding = mm.SubjectEncoding;  
                foreach (AlternateView av in mm.AlternateViews)  
                     AlternateViews.Add(SerializeableAlternateView.GetSerializeableAlternateView(av));  
           }  
           /// <summary>  
           /// Returns the MailMessge object from the serializeable object  
           /// </summary>  
           /// <returns></returns>  
           public MailMessage GetMailMessage()  
           {  
                MailMessage mm = new MailMessage();  
                mm.IsBodyHtml = IsBodyHtml;  
                mm.Body = Body;  
                mm.Subject = Subject;  
                if( From != null )  
                     mm.From = From.GetMailAddress();  
                foreach (SerializeableMailAddress ma in To)  
                {  
                     mm.To.Add(ma.GetMailAddress());  
                }  
                foreach (SerializeableMailAddress ma in CC)  
                {  
                     mm.CC.Add(ma.GetMailAddress());  
                }  
                foreach (SerializeableMailAddress ma in Bcc)  
                {  
                     mm.Bcc.Add(ma.GetMailAddress());  
                }  
                foreach (SerializeableAttachment att in Attachments)  
                {  
                     mm.Attachments.Add(att.GetAttachment());  
                }  
                mm.BodyEncoding = BodyEncoding;  
                mm.DeliveryNotificationOptions = DeliveryNotificationOptions;  
                Headers.SetColletion(mm.Headers);  
                mm.Priority = Priority;  
                if (ReplyTo != null)  
                     mm.ReplyTo = ReplyTo.GetMailAddress();  
                if (Sender != null)  
                     mm.Sender = Sender.GetMailAddress();  
                mm.SubjectEncoding = SubjectEncoding;  
                foreach (SerializeableAlternateView av in AlternateViews)  
                     mm.AlternateViews.Add(av.GetAlternateView());  
                return mm;  
           }  
      }  
 }  

Third party webservices

Every time I have to make integration with third party webservices I always try to detach the application from the webservice due to the constant errors/problems with webservices.

I am still looking for an easy way to make a test page that easily test and validates a given webservice and method.

I always spent a lot of time assuring that it isnt some bug I have introduced in my application that has broken the webservice integration.

Once in a while it is some bug introduced by myself but in 8 out of 10 times it is data that the webservice collect that are invalid or the webservice itself that fails.

I will write my experiences with this issue here and try to create an easy way of testing a webservice.

But please share if you have any ideas.

Me and sitecore

This blog exists because I have a love/hate relationship with the CMS created by Sitecore which is a big part of my job as a web developer in Netmester A/S in Denmark.

I am always challeging Sitecore and Sitecore unfornunately often breaks to all the weird stuff Im doing to it every day.

Ill create blogs about all the weird stuff I meet and struggles to solve every day.

And this is the first in many.

Im at the moment developing a solution in Sitecore 6.1.0 which is currently the latest Sitecore release (not recommended version).

One of the new things in Sitecore 6 is that all security (rights, roles and other membership related stuff) are implemented using standard asp.net security rather than using Sitecores own security.
This should in itself be an approvement but sitecore has for one thing decided to implement the Sitecore domain functionality as part of the username which I personally think is pretty stupid.

Im using a third party member system that supplies users to the website (username, email, name etc).

In order to be able to log out this user, after login, using FormsAuthentication.SignOut() the user NEEDS to be added to the asp.net
Membership and therefore is visible in Sitecore security editor. With more than 5000 users this makes the security editor a bit crowded.
In order to put the users in a customer specific domain I need to prefix the user with the domain name followed by a backslash (\)
This makes it hard to map the sitecore user with the third pary member system or at least makes it more complicated because I now need to remove
the domain name from the sitecore user or append the domain name to the third party username.



I can live with this but the latest issue I have found is not easy to solve.
When redirecting from a page in my website (to login page due to user not logged in) sitecore throws an error looking like this

 System.InvalidOperationException: user at Sitecore.Caching.UserProfile.UserProfileCache.GetRecord(String userName, String propertyName)  
 at Sitecore.Security.UserProfile.GetPropertyValueCore(String propertyName)  
 at Sitecore.Security.UserProfile.get_SerializedData()  
 at Sitecore.Security.UserProfile.get_CustomProperties()  
 at Sitecore.Security.UserProfile.SerializeCustomProperties()  
 at Sitecore.Security.UserProfile.Save()  
 at System.Web.Profile.ProfileModule.OnLeave(Object source, EventArgs eventArgs)  
 at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()  
 at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)  

This exception is thrown in another thread than the request is executing in because no Session is available when I pick up the exception in Global.asax.

No user is logged in when the exception is thrown and it makes sense that the GetRecord() failes due to username is empty.

I have added a profile provider and a profile property that makes it possible to get a DB instance of the user logged in. This might be the trigger of the exception but I havnt been able to solve the bug.

This is the profile section of the web.config

 <profile defaultProvider="sql" enabled="true" inherits="Sitecore.Security.UserProfile, Sitecore.Kernel">  
  <providers>  
   <clear/>  
   <add name="sql" type="System.Web.Profile.SqlProfileProvider" connectionStringName="core" applicationName="sitecore"/>  
   <add name="switcher" type="Sitecore.Security.SwitchingProfileProvider, Sitecore.Kernel" applicationName="sitecore" mappings="switchingProviders/profile"/>  
   <add name="CommunityProfileProvider" applicationName="Community" type="Netmester.Profile.GenericProfileProvider" connectionStringName="Community"/>  
  </providers>  
  <properties>  
   <clear/>  
   <add type="System.String" name="SC_UserData"/>  
   <add name="CommunityProfile" provider="CommunityProfileProvider" type="Netmester.Framework.Community.DomainObjects.User"/>  
  </properties>  
 </profile>