Hi,

I am trying to create ATLAS enabled Drag-Drop webparts dynamically (!)  ..Webparts will be created from database. And so I've implemented custom WebpartManager, WebPart, WebPartZone, etc and I am instantiate them in OnInit() of the page. Now I have couple of problems...

1) On postback, webparts are gettind duplicated. I am pretty sure there is something to do with personalisation stored in ASPNETDB database (App_Data folder). I want to completely DISABLE the aspnetdb, because I am also authenticating users dynamically.

2) When I edit any webpart I get this exception...
    System.InvalidOperationException: Should only have editor parts in the ZoneTemplate of 'editor'.

This is how I create EditZone:


here is the code for ControlHolder class
   public class ControlHolder : ITemplate {
      Control ctrl = new Control();

      public ControlHolder() {
         ctrl.Controls.Clear();
         ctrl.Controls.Add(new LiteralControl("control list is empty."));
      }

      public ControlHolder(Control _ctrl) {
         ctrl.Controls.Clear();
         if (_ctrl == null) {
            ctrl.Controls.Add(new LiteralControl("control list is empty."));
         }
         else {
            ctrl.Controls.Add(_ctrl);
         }
      }

      void ITemplate.InstantiateIn(Control owner) {
         owner.Controls.Add(ctrl);
      }
   }


Please help me solving above problems.

Thanks,
Haresh

hareshgpatel:

Hi,
I am trying to create ATLAS enabled Drag-Drop webparts dynamically (!)  ..Webparts will be created from database. And so I've implemented custom WebpartManager, WebPart, WebPartZone, etc and I am instantiate them in OnInit() of the page. Now I have couple of problems...

My collegues and I have been struggling with this also. Finally we've found a solution: everything can be standard (although our webparts are .ascx files which derive from a base class that inherits from IWebPart), however you need to use a custom CatalogPart in the CatalogZone's ZoneTemplate.

Helpful sites:
http://www.carlosag.net/articles/WebParts/catalogPartSample.aspx
http://www.codeproject.com/aspnet/DropDownCatalogZone.asp

Some sample code (but please make sure to look at http://www.carlosag.net/articles/WebParts/catalogPartSample.aspx , lots of it is derived from that example!):

  

    public class MyCatalogPart : CatalogPart
    {
        WebPartDescriptionCollection _description;
        Dictionary<string, WebPart> _loadedWebparts;
		
        public MyCatalogPart()
        {
        }
		
        public override string Title
        {
            get
            {
                string title = base.Title;
                return string.IsNullOrEmpty(title) ? "My Catalog Part" : title;
            }
            set
            {
                base.Title = value;
            }
        }
		
        public override WebPartDescriptionCollection GetAvailableWebPartDescriptions()
        {
            if (this.DesignMode)
            {
                return new WebPartDescriptionCollection(new object[] {
                    new WebPartDescription("1", "Xml WebPart 1", null, null),
                    new WebPartDescription("2", "Xml WebPart 2", null, null),
                    new WebPartDescription("3", "Xml WebPart 3", null, null)});
            }

            if (_description == null)
                this.GetWebParts();

            return this._description;
		}
		
		// VERY IMPORTANT -- NOT MENTIONED IN ARTICLES!
		// to REMOVE the webparts from the catalog after adding them, you need code like this:
		// if you don't do this, the webparts will still be present in the catalog after adding them
        protected override void OnPreRender(EventArgs e)
        {
            string sCheckBoxKey = Zone.UniqueID + "$_checkbox";
            string sActionKey = "__EVENTARGUMENT";
			
            string sCheckBox = string.Empty;
            if (HttpContext.Current.Request[sCheckBoxKey] != null)
            {
                sCheckBox = HttpContext.Current.Request[sCheckBoxKey].ToString();
            }

            string sAction = string.Empty;
            if (HttpContext.Current.Request[sActionKey] != null)
            {
                sAction = HttpContext.Current.Request[sActionKey].ToString();
            }

            Hashtable htSelected = new Hashtable();
            foreach (string sSel in sCheckBox.Split(','))
            {
                htSelected.Add(sSel, true);
            }

            if (sAction == "add" && _description != null)
            {
                List list = new List();

                foreach (WebPartDescription oWPD in _description)
                {
                    if (htSelected[oWPD.ID] == null)
                    {
                        list.Add(oWPD);
                    }
                }

                this._description = new WebPartDescriptionCollection(list);
            }

            base.OnPreRender(e);
        }

        private void GetWebParts()
        {
            WebPartDescription description = null;
            List list = new List();
            this._loadedWebparts = new Dictionary<string, WebPart>();
			
			// retrieve the web parts from the database:
            List lMWP = GetMyWebParts();

            foreach (MyWebPart oMWP in lMWP)
            {
                WebPart oWP = CreateWebPartFromMyWebPart(oMWP);

                if ((oWP != null) && ((base.WebPartManager == null) || (base.WebPartManager.IsAuthorized(oWP)) && (!IsWebPartLoaded(oWP))))
                {
                    description = new WebPartDescription(oWP);
                    list.Add(description);
                    this._loadedWebparts.Add(description.ID, oWP);
                }
            }
            this._description = new WebPartDescriptionCollection(list);
        }

        private WebPart CreateWebPartFromMyWebPart(MyWebPart oSWP)
        {
            WebPart webPart = null;

            if (oSWP.Type.LastIndexOf(".ascx") > 0)
            {
                Control control = this.Page.LoadControl(oSWP.Type);
                control.ID = oSWP.ID;

                if (base.WebPartManager != null)
                    webPart = base.WebPartManager.CreateWebPart(control);
            }
            else
            {
                Type type = Type.GetType(oSWP.Type);
                webPart = Activator.CreateInstance(type, null) as WebPart;
            }

            webPart.ID = oSWP.ID;
            webPart.Title = oSWP.Title;
            webPart.CatalogIconImageUrl = oSWP.ImageUrl;
            webPart.AuthorizationFilter = oSWP.AuthorizationFilter;

            return webPart;
        }

        private bool IsWebPartLoaded(WebPart oWP)
        {
            foreach (WebPart oWebPart in base.WebPartManager.WebParts)
            {
                if (oWP.Title == oWebPart.Title)
                    return true;
            }
            return false;
        }
	}

 

Hello,

Can someone explain what this line is doing.

        Dictionary<string, WebPart> _loadedWebparts;

I've looked at the sample Catalog from Carlos and like the extras this sample suggest such as deleting from a Catalog.

However, I work in VB and have an error when convert the entire Class to VB.

 Regardless of what I try I get an error that it doesn't know what Dictionary is.

I tried this and other derivations.

Private _loadedWebparts As Dictionary(Of String, WebPart)

 

Thanks!

 

VBMan:

Can someone explain what this line is doing.

        Dictionary<string, WebPart> _loadedWebparts;

This contains the list of WebParts. Mind you, it could be not all of the code above is necessary, it's a cropped version of the code we use and some of it has to do with stuff we need. The best way to look at the code above is as inspiration, you don't need to slavishly follow it to succeed. Look at what it does, how it does it and why it does it (and when it does it).

Now I remember where _loadedWebparts is used: look at http://www.carlosag.net/articles/WebParts/catalogPartSample.aspx , there's public override WebPart GetWebPart(WebPartDescription description) and in our version of that method we do this:

public override WebPart GetWebPart(WebPartDescription description)
{
	if (this._loadedWebparts == null)
		this.GetWebParts();
		
	return this._loadedWebparts[description.ID];
}

 I don't know about using Dictionary in VB (and IMHO that question isn't relevant in this forum anyway). Perhaps you can use a HashTable instead?

BCdotNet, Thanks for trying to help.

I am new to .net 2.0 and a VB programmer so learning C# on the fly is problematic at best.

I am unable to resolve using your sample because the code I mentioned is not recognized in C#, so I expect either you have some background code to allow them to be used.

These lines are not recognized without some type of additional coding/assemblies and without seeing a working sample I am unable to take the next step.

        Dictionary<string, WebPart> _loadedWebparts;
        List list = new List();
        List list = new List();
        this._loadedWebparts = new Dictionary<string, WebPart>();

These lines generate errors when trying to compile as List and Dictionary<...> are not recognized.

 

 

You need to "import" or "use" the proper classes. If you don't know which class List or Dictionary belongs to, use Visual Studio's help.

Hey, I am also having the same issue.

 We have a requirement of showing the webparts based on the database values.. ie., we will be creating the Dynamic Webpart and also the WebPartZone.

When I try to populate the Webpart on to the UI, first time it shows fine but when I do the postback, the WebParts are getting duplicated. How can I resolve this error?

 
Warm Regards,

Ravi Kalyan
 

Look at the code above, and use it as a guide. We don't use dynamic WebPartZones, however, but we did solve the duplication problem.

BCdotNET:

Look at the code above, and use it as a guide. We don't use dynamic WebPartZones, however, but we did solve the duplication problem.

Ya, I tried creating the CustomCatalogPart class extending from CatalogPart. But problem is that how can I add my custom class to CatalogZone? Please provide me any samples if u have.

 
Regards

 

hi

i am following the link you have given here

http://www.carlosag.net/articles/WebParts/catalogPartSample.aspx

when i am running that application i am gettign error in the following funtion

public override WebPart GetWebPart(WebPartDescription description)

{

string typeName = this.GetTypeNameFromXml(description.ID);

Type type =Type.GetType(typeName);

return Activator.CreateInstance(type, null) as WebPart;

}

 in the type i m not gettign the type of webpart type.. it returning null...

 

Haresh,

I am also having the same situation where i wanted to use the authentication and not the personalisation stored in ASPNETDB database (App_Data folder). I want to completely DISABLE the aspnetdb, because I am also authenticating users dynamically.

Did you have any luck with your question and have you found any solution

Can share your example to this piece of code as how you were able to implement this 

 

Sudhir,

This is how I DISABLED and DELETED the aspnetDB database from APP_Data folder:

1) In Web.Config file add the following
...
  <system.web>
     <webParts>
       <personalization defaultProvider="VoidPersonalizationProvider">
         <providers>
           <add name="VoidPersonalizationProvider"
                type="MyApp.VoidPersonalizationProvider" />
         </providers>

...

     </webParts>
...

2) Add VoidPersonalizationProvider class to your project
using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections.Specialized;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Hosting;
using System.Diagnostics;

namespace MyApp
{
   //This class is just to disable ASPNETDB database
   public class VoidPersonalizationProvider : PersonalizationProvider
    {
      private string _applicationName;

      public override string ApplicationName {
         get {
            if (string.IsNullOrEmpty(_applicationName))
               _applicationName = HostingEnvironment.ApplicationVirtualPath;
            return _applicationName;
         }
         set {
            _applicationName = value;
         }
      }

      public override void Initialize(string name, NameValueCollection configSettings) {
         base.Initialize(name, configSettings);
      }

      public override PersonalizationStateInfoCollection FindState(PersonalizationScope scope,
             PersonalizationStateQuery query, int pageIndex, int pageSize, out int totalRecords) {
         totalRecords = 1;
         return null;
      }

      public override int GetCountOfState(PersonalizationScope scope, PersonalizationStateQuery query) {
         return -1;
      }

      public override int ResetUserState(string path, DateTime userInactiveSinceDate) {
         return 0;
      }

      protected override void LoadPersonalizationBlobs(WebPartManager webPartManager, string path,
                     string userName, ref byte[] sharedDataBlob, ref byte[] userDataBlob) {
      }

      protected override void ResetPersonalizationBlob(WebPartManager webPartManager, string path,
                                            string userName) {
      }

      public override int ResetState(PersonalizationScope scope, string[] paths, string[] usernames) {
         return 0;
      }

      protected override void SavePersonalizationBlob(WebPartManager webPartManager, string path,
                                string userName, byte[] dataBlob) {
      }
    }

}

3. Delete ASPNETDB database from APP_Data folder