How to implement Resource paging

HOW-TO

Implement Resource paging.

## DESCRIPTION

One nice way to display a long list of resources in RadScheduler and improve performance is to use paging:

Pagination for resources is not provided out-of-the-box, but it can easily be implemented with a little bit of coding.

SOLUTION

The underlying method to achieve the above described functionality is to manipulate the Resources collection of RadScheduler in its DataBound event. We cycle through all resources and remove those that do not fall in the currently selected range. We also add those resources which we have removed to another collection saved in a session and use it in FormCreating to populate the resources which we have removed in DataBound.

private const int PageSize = 2;

    protected void Page_Init(object sender, EventArgs e)
    {
        XmlSchedulerProvider provider = new XmlSchedulerProvider(Server.MapPath("~/App_Data/Appointments_MultipleResources.xml"), true);
        RadScheduler1.Provider = provider;
    }
    protected void RadScheduler1_DataBound(object sender, EventArgs e)
    {
        RadScheduler1.ResourceTypes.FindByName("User").AllowMultipleValues = true;
        int pageIndex = (int?)ViewState["PageIndex"] ?? 0;
        IList<Resource> pagedResources = new List<Resource>(RadScheduler1.Resources.GetResourcesByType("User"));
        IList<Resource> remainingResources = new List<Resource>();
        int resourceCount = pagedResources.Count;
        int pageStart = pageIndex * PageSize;
        int pageEnd = pageStart + PageSize;

        int resourceIndex = 0;
        foreach (Resource resource in pagedResources)
        {
            if (resourceIndex < pageStart || resourceIndex >= pageEnd)
            {
                RadScheduler1.Resources.Remove(resource);
                remainingResources.Add(resource);
            }  
            resourceIndex++;
        }
        int pageEndToDisplayInPagingStatus = pageStart + RadScheduler1.Resources.GetResourcesByType("User").Count;
        Session["remainingResources"] = remainingResources;
        PagingStatus.Text = string.Format("Showing pages {0} to {1} of {2} total.", pageStart + 1, pageEndToDisplayInPagingStatus, resourceCount);
        int pageCount = (int) Math.Ceiling((double)resourceCount / (double)PageSize);
        NextPage.Enabled = pageIndex < pageCount-1;
        PrevPage.Enabled = pageIndex > 0;
    }
    protected void NextPage_Click(object sender, EventArgs e)
    {
        int pageIndex = (int?)ViewState["PageIndex"] ?? 0;
        pageIndex++;
        ViewState["PageIndex"] = pageIndex;
        RadScheduler1.Rebind();
    }
    protected void PrevPage_Click(object sender, EventArgs e)
    {
        int pageIndex = (int?)ViewState["PageIndex"] ?? 0;
        pageIndex = Math.Max(pageIndex - 1, 0);
        ViewState["PageIndex"] = pageIndex;
        RadScheduler1.Rebind();
    }

    protected void RadScheduler1_AppointmentCommand(object sender, AppointmentCommandEventArgs e)
    {
        if (e.CommandName == "Cancel")
            RadScheduler1.Rebind();
    }
    protected void RadScheduler1_FormCreating(object sender, SchedulerFormCreatingEventArgs e)
    {
        if (e.Mode == SchedulerFormMode.AdvancedEdit || e.Mode == SchedulerFormMode.AdvancedInsert)
        {
            IList<Resource> remainingResources = Session["remainingResources"] as List<Resource>;
            if (remainingResources != null)
            {
                foreach (Resource resource in remainingResources)
                {
                    RadScheduler1.Resources.Add(resource);
                }
                Session.Remove("remainingResources");
            }
        }
    }

Private Const PageSize As Integer = 2
   Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
       Dim provider As New XmlSchedulerProvider(Server.MapPath("~/App_Data/Appointments_MultipleResources.xml"), True)
       RadScheduler1.Provider = provider
   End Sub
   Protected Sub RadScheduler1_DataBound(ByVal sender As Object, ByVal e As EventArgs)
       RadScheduler1.ResourceTypes.FindByName("User").AllowMultipleValues = True
       Dim pageIndex As Integer = If(DirectCast(ViewState("PageIndex"), System.Nullable(Of Integer)), 0)
       Dim pagedResources As IList(Of Resource) = New List(Of Resource)(RadScheduler1.Resources.GetResourcesByType("User"))
       Dim remainingResources As IList(Of Resource) = New List(Of Resource)()
       Dim resourceCount As Integer = pagedResources.Count
       Dim pageStart As Integer = pageIndex * PageSize
       Dim pageEnd As Integer = pageStart + PageSize
       Dim resourceIndex As Integer = 0
       For Each resource As Resource In pagedResources
           If resourceIndex < pageStart OrElse resourceIndex >= pageEnd Then
               RadScheduler1.Resources.Remove(resource)
               remainingResources.Add(resource)
           End If
           System.Math.Max(System.Threading.Interlocked.Increment(resourceIndex), resourceIndex - 1)
       Next
       Dim pageEndToDisplayInPagingStatus As Integer = pageStart + RadScheduler1.Resources.GetResourcesByType("User").Count
       Session("remainingResources") = remainingResources
       PagingStatus.Text = String.Format("Showing pages {0} to {1} of {2} total.", pageStart + 1, pageEndToDisplayInPagingStatus, resourceCount)
       Dim pageCount As Integer = Math.Ceiling(resourceCount / PageSize)
       NextPage.Enabled = pageIndex < pageCount - 1
       PrevPage.Enabled = pageIndex > 0
   End Sub
   Protected Sub NextPage_Click(ByVal sender As Object, ByVal e As EventArgs)
       Dim pageIndex As Integer = If(DirectCast(ViewState("PageIndex"), System.Nullable(Of Integer)), 0)
       System.Math.Max(System.Threading.Interlocked.Increment(pageIndex), pageIndex - 1)
       ViewState("PageIndex") = pageIndex
       RadScheduler1.Rebind()
   End Sub
   Protected Sub PrevPage_Click(ByVal sender As Object, ByVal e As EventArgs)
       Dim pageIndex As Integer = If(DirectCast(ViewState("PageIndex"), System.Nullable(Of Integer)), 0)
       pageIndex = Math.Max(pageIndex - 1, 0)
       ViewState("PageIndex") = pageIndex
       RadScheduler1.Rebind()
   End Sub
   Protected Sub RadScheduler1_FormCreating(ByVal sender As Object, ByVal e As Telerik.Web.UI.SchedulerFormCreatingEventArgs)
       If e.Mode = SchedulerFormMode.AdvancedEdit OrElse e.Mode = SchedulerFormMode.AdvancedInsert Then
           Dim remainingResources As IList(Of Resource) = TryCast(Session("remainingResources"), List(Of Resource))
           If Not remainingResources Is Nothing Then
               For Each resource As Resource In remainingResources
                   RadScheduler1.Resources.Add(resource)
               Next
               Session.Remove("remainingResources")
           End If
       End If
   End Sub
   Protected Sub RadScheduler1_AppointmentCommand(ByVal sender As Object, ByVal e As Telerik.Web.UI.AppointmentCommandEventArgs)
       If e.CommandName = "Cancel" Then
           RadScheduler1.Rebind()
       End If
   End Sub