DaST Concept: A simpler, smarter, and much more powerful alternative to Forms and MVC.

// VideoLibrary DEMO - DaST Technology Demonstrator
// Copyright (C) 2011 Roman Gubarenko 
// http://www.rgubarenko.net
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
// 
// Licence terms for AspNetDaST.dll (in Bin folder) are below.
// 
// ASP.NET DaST Rendering Engine (BETA version)
// Copyright (C) 2011 Roman Gubarenko
// http://www.rgubarenko.net
// 
// Redistribution and use of BETA version of DaST Rendering Engine 
// is permitted in binary form without modification. Only original and
// unmodified .NET dll (AspNetDaST.dll) can be used in your own projects and 
// redistributed. You may not copy, decompile, reverse engineer, disassemble, 
// modify, or create derivative works of the software or any part thereof.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE.
//
// DaST technology dev site: http://www.rgubarenko.net
// My contact email for questions: rgubarenko@gmail.com


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using AspNetDaST.Web;

/// <summary>
/// Summary description for PagerController
/// </summary>
public class PagerController : ScopeController
{
  public override void SetTemplate(SetTemplateArgs template)
  {
    template.Markup = Utils.LoadTemplate("PagerTemplate.htm");
  }

  public override void SetupModel(ControllerModelBuilder model)
  {
    model.SetDataBind(new DataBindHandler(ROOT_DataBind));

    model.HandleAction("NextPage", new ActionHandler(Action_NextPage));
    model.HandleAction("PrevPage", new ActionHandler(Action_PrevPage));

    model.RegisterMethod("UpdatePagerValues", new MethodHandler(UpdatePagerValues));
  }


  private void Action_NextPage(ActionArgs args)
  {
    int startItemIdx = ControlPath.Scope.Param<int>("StartItemIdx");
    int pageSize = ControlPath.Scope.Param<int>("PageSize");
    int itemTotalCount = ControlPath.Scope.Param<int>("ItemTotalCount");

    if (startItemIdx + pageSize <= itemTotalCount)
    {
      startItemIdx = startItemIdx + pageSize;
      ControlPath.Scope.SetParam("StartItemIdx", startItemIdx);

      RaiseAction("NextPage", null);
    }
  }

  private void Action_PrevPage(ActionArgs args)
  {
    int startItemIdx = ControlPath.Scope.Param<int>("StartItemIdx");
    int pageSize = ControlPath.Scope.Param<int>("PageSize");
    int itemTotalCount = ControlPath.Scope.Param<int>("ItemTotalCount");

    if (startItemIdx > 0)
    {
      startItemIdx = startItemIdx - pageSize;
      ControlPath.Scope.SetParam("StartItemIdx", startItemIdx);

      RaiseAction("PrevPage", null);
    }
  }


  private void ROOT_DataBind()
  {
    UpdatePagerValues(null);

    int startItemIdx = CurrentPath.Scope.Param<int>("StartItemIdx");
    int pageSize = CurrentPath.Scope.Param<int>("PageSize");
    int itemCount = CurrentPath.Scope.Param<int>("ItemTotalCount");

    if (startItemIdx >= 0 && pageSize > 0 && itemCount > 0)
    {
      int currPage = startItemIdx / pageSize + (startItemIdx % pageSize == 0 ? 0 : 1); ;
      int pageCount = itemCount / pageSize + (itemCount % pageSize == 0 ? 0 : 1);

      CurrentPath.Scope.Replace("{PrevPageIdx}", currPage > 0 ? currPage - 1 : 0);
      CurrentPath.Scope.Replace("{NextPageIdx}", currPage + 1);
      CurrentPath.Scope.Replace("{CurrPageNum}", currPage + 1);
      CurrentPath.Scope.Replace("{TotalPageCount}", pageCount);

      CurrentPath.Fwd("PrevEnabled").Scope.Replace("{PrevPageIdx}", currPage > 0 ? currPage - 1 : 0);
      CurrentPath.Fwd("NextEnabled").Scope.Replace("{NextPageIdx}", currPage + 1);

      if (currPage > 0)
      {
        CurrentPath.Fwd("PrevEnabled").Scope.RenderType = ScopeRenderType.Normal;
        CurrentPath.Fwd("PrevDisabled").Scope.RenderType = ScopeRenderType.None;
      }
      else
      {
        CurrentPath.Fwd("PrevEnabled").Scope.RenderType = ScopeRenderType.None;
        CurrentPath.Fwd("PrevDisabled").Scope.RenderType = ScopeRenderType.Normal;
      }

      if (currPage < pageCount - 1)
      {
        CurrentPath.Fwd("NextEnabled").Scope.RenderType = ScopeRenderType.Normal;
        CurrentPath.Fwd("NextDisabled").Scope.RenderType = ScopeRenderType.None;
      }
      else
      {
        CurrentPath.Fwd("NextEnabled").Scope.RenderType = ScopeRenderType.None;
        CurrentPath.Fwd("NextDisabled").Scope.RenderType = ScopeRenderType.Normal;
      }
    }
    else
    {
      CurrentPath.Scope.RenderType = ScopeRenderType.Empty;
    }
  }


  private object UpdatePagerValues(object jsonData)
  {
    int startItemIdx, pageSize, itemTotalCount;
    if (DaSTUtils.HasValue("StartItemIdx", jsonData)) startItemIdx = (int)DaSTUtils.GetValue("StartItemIdx", jsonData);
    else startItemIdx = ControlPath.Scope.Param<int>("StartItemIdx", 0);
    if (DaSTUtils.HasValue("PageSize", jsonData)) pageSize = (int)DaSTUtils.GetValue("PageSize", jsonData);
    else pageSize = ControlPath.Scope.Param<int>("PageSize", 1);
    if (DaSTUtils.HasValue("ItemTotalCount", jsonData)) itemTotalCount = (int)DaSTUtils.GetValue("ItemTotalCount", jsonData);
    else itemTotalCount = ControlPath.Scope.Param<int>("ItemTotalCount", 0);

    startItemIdx = Math.Min(startItemIdx, itemTotalCount - 1);
    startItemIdx = ((int)(startItemIdx / pageSize)) * pageSize;
    
    // set recalculated values
    ControlPath.Scope.SetParam("StartItemIdx", startItemIdx);
    ControlPath.Scope.SetParam("PageSize", pageSize);
    ControlPath.Scope.SetParam("ItemTotalCount", itemTotalCount);

    return null;
  }
}