Rebranding webpart URLs in runtime

Introduction

This article gives one of the practical usages of the .NET reflection concept in SharePoint webparts. We can make use of this concept to change the properties of the SharePoint webparts during runtime in a bulk manner. I have used this for changing the URLs from old to new referred in the CorasWorks webparts and Image webparts.

Background

The CorasWorks suite is used for roll up of all the lists in a SharePoint system. The challenge here is when the portal and the sites are restored, the weparts in the new system will have the links pointed to old URL. The CorasWorks store the "SiteURL" and "ListNames" properties in the .dwp file of that webpart.

All SharePoint developers know that the webparts are associated with a .dwp file and the data associated with the webparts are not stored in the database. The webpart specific data are stored in the .dwp file and so this has to be changed to the new one. You might wonder what the big deal is, but suppose the system has thousands of wss sites and least one CorasWorks webpart is there. Hope you can recognize the criticality now.

I need to really appreciate the "Reflection" concept of .NET here.

• The webparts are iterated for all the webs using the GetWebPartCollection of the SPWeb object and the webpart type is identified using GetType() method.
• Using the GetMember() method of the object, the Members[] array is created.
• A PropertyInfo object is created based on the Members element.
• Then the GetValue() and SetValue() method of PropertyInfo helps in getting the old value, replacing the new one and setting it back.

Once the value is set, the webpart values are saved using the SaveChanges method of the SPWebPartCollection object.

Note: This can be done only for the wss sites and not for portal areas due to permission restriction of saving the webpart values.

Using the code

The code shows looping through the virtual servers (the IIS websites linked to SharePoint) and all further sites. It looks for the type of the webpart.

SPGlobalAdmin global = new SPGlobalAdmin();
string webname = string.Empty;
#region looping Virtual servers
for(int count=1; count<=2; count++)
{
    SPSiteCollection allSitesOnServer = global.VirtualServers[count].Sites;
    int totalSites = allSitesOnServer.Count;
    for(int sitesCount =0;sitesCount<totalSites;sitesCount++)
    {
        try
        {
            SPSite allSites = allSitesOnServer[sitesCount];
            SPWebCollection allWebs = allSites.AllWebs;
            #region looping web collection
            foreach(SPWeb currentWeb in allWebs)
            {
                webname = currentWeb.Url ;
                // Get the webpart collection
                SPWebPartCollection webParts = currentWeb.GetWebPartCollection
                    ("default.aspx",Storage.Shared);
                for(int i=0; i<webParts.Count;i++)
                {
                    WebPart currentWebPart = webParts[i];
                    object obj = null;
                    Type typeobj = currentWebPart.GetType();
                    // condition to check the webpart is of type ImageWebpart.
                    // you can put which webpart you are looking for.
                    if(currentWebPart.GetType().FullName.EndsWith
                            ("ImageWebPart"))
                    {
                        Log("The Image webparts " + 
                    currentWebPart.GetType().FullName);
                        Log("Info of " + currentWeb.Url + ":");
                        currentWebPart.AllowZoneChange = true;
                        // Read the properties and change to the 
                        // new values in the webpart
                        WebPart newWebPart = ReadUpdatePropertyValues
                    (currentWebPart,typeobj,obj,oldUrl,newUrl);
                        // Save the changes to the webpart
                        webParts.SaveChanges(newWebPart.StorageKey);
                    }
                }
            }
            #endregion
        }

        catch(Exception ex)
        {
            Log("Error in : " + webname + "--->" + ex.Message);
        }
    }
}

public static WebPart ReadUpdatePropertyValues
 (WebPart wpart,Type wptype, object obj,string oldUrl,string newUrl)
{
    try
    {
        // string array to get selected properties
        string[] wpProps = new string[]{"ImageLink"};
        #region looping through properties
        foreach (string wpProp in wpProps)
        {
            MemberInfo[] members = wptype.GetMember(wpProp);
            if(members.Length != 1)
            {
                Log(failed+": Not handled - No required property " + 
                            wpart.Title );
                // counter to find the number of unhandled coras webparts
                failed++;
            }
            else
            {
                switch(members[0].MemberType)
                {
                    case MemberTypes.Property :
                    {
                        PropertyInfo prop = (PropertyInfo)members[0];
                        // Gets the value of the property
                        obj = prop.GetValue(wpart, new object[0]);
                        string newurl = obj.ToString().Replace(oldUrl,newUrl);
                        // Log("OLD URL : " + oldUrl );
                        if(newurl != obj.ToString())
                        {
                            object strVal = (object)newurl;
                            // Sets the value of the property
                            prop.SetValue(wpart, strVal ,new object[0]);
                            Log(changed + ": " + wpart.Title + 
                        " : Changed property");
                            Log(changed + ": " + newurl + 
                        " : Changed property");
                            changed++;
                        }
                    }
                    break;
                    case MemberTypes.Field :
                    {
                        FieldInfo field = (FieldInfo)members[0];
                        obj = field.GetValue(wpart);
                        string newurl = obj.ToString().Replace(oldUrl,newUrl);
                        object strVal = (object)newurl;
                        field.SetValue(wpart,strVal);
                    }
                    break;
                    default :
                    throw new Exception("Not found");
                }
            }
            Log(success +": " +wpart.Title+" : Has property");
            // counter to find the number of coras webparts 
            // which has that property
            success++;
        }
        #endregion
    }
    catch(Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
    return wpart;
}