jqGrid loadonce doesn’t work with asp.net

Does anyone know how to solve this nasty issue with asp.net+asmx+jqGrid sorting.
Because, in order to call pagemethods or asmx web services from jqGrid, it needs to be hacked like this:

datatype: function() {
                    $.ajax({
                        url: 'Default.aspx/GetPersons',
                        data: "{}",
                        type: "POST",
                        dataFilter: function(data) {
                            var msg = eval('(' + data + ')');
                            if (msg.hasOwnProperty('d'))
                                return msg.d;
                            else
                                return msg;
                        }

instead of this:

datatype: "json"

Because of that, setting loadonce attribute to true in order to do my sortings on the client, doesn’t work and jqGrid calls server for every event that occur in grid.

Any ideas?

Thanx
Marko

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

It’s a little bit late, but here’s a (the?) super-easy solution for any future solution-seekers:

gridComplete: function(){ 
  $("#yourGridID").setGridParam({datatype: 'local'}); 
}

That’s it. I’m using 3.7.2, can’t speak for any other versions. The problem (apparently) stems from ‘loadonce’ only working with the pre-defined datatype values, which a function is not. I believe the other built-in values will also work, but ‘local’ makes sense.

Method 2

I eventually gave up on JSON (with ASP.NET) and just used XML. Then everything just works.
Make sure the return type from your asmx is XmlDocument

A good summary of everything you need to do to make it work (on the client side at least) can be found on the the JQGrid wiki

Look at their sample XML and make sure what your service returns a buffer (best to validate with Fiddler) that follows the same schema.

UPDATE – Some Code samples

Here is the client side script to create the grid

     var mygrid = $("#list").jqGrid({
      url: '../../webServices/callsGridService.asmx/getCallsGridDataXML?nd=' + new Date().getTime(),
      datatype: 'xml',
      mtype: 'POST',
      contentType: "text/xml",
      colNames: ['Call ID', 'Date / Time', 'Duration'],
      colModel: [
      { name: 'callId', index: 'callId', align: "right", key: true },
  { name: 'callTime', index: 'callTime', sorttype: 'date' },
      { name: 'duration', index: 'duration', align: "right" }
    ],
      pager: $('#pager'),
      rowNum: 10,
      rowList: [10, 25, 50, 100],
      sortname: 'callTime',
      viewrecords: true,
      sortorder: "desc",
      height: "100%",
      multiselect: true,
      rownumbers: true,
      gridview: true,
      autowidth: true,
      caption: "Calls"
    })

And here is the service code (VB.NET):

  Public Function getCallsGridDataXML() As XmlDocument
    Dim xmlRet As New XmlDocument
    Dim ret As New StringBuilder

    m_pageNum = CInt(HttpContext.Current.Request.Form.Item("page"))
    If m_pageNum = Nothing OrElse m_pageNum = 0 Then
      m_pageNum = 1
    End If
    m_pageSize = CInt(HttpContext.Current.Request.Form.Item("rows"))
    If m_pageSize = Nothing OrElse m_pageSize = 0 Then
      m_pageSize = 10
    End If
    m_sortItem = CStr(HttpContext.Current.Request.Form.Item("sidx"))
    m_sortOrder = CStr(HttpContext.Current.Request.Form.Item("sord"))

    Dim dt As DataTable
    dt = Session(SESSION_CALLS_GRID_DATA)

    Dim myView As DataView = dt.DefaultView
    If m_sortItem IsNot Nothing AndAlso m_sortOrder IsNot Nothing Then
      myView.Sort = m_sortItem & " " & m_sortOrder
    End If

    ret.Append("<?xml version='1.0' encoding='utf-8'?>")
    ret.Append("<rows>")
    ret.Append("<page>" & m_pageNum & "</page>")
    ret.Append("<total>" & Math.Floor(dt.Rows.Count / m_pageSize) & "</total>")
    ret.Append("<records>" & dt.Rows.Count & "</records>")

    For i As Integer = (m_pageNum - 1) * m_pageSize To Math.Min(dt.Rows.Count - 1, m_pageNum * m_pageSize - 1)
      ret.Append("<row>")
      Dim cellCount As Integer = 0

      ret.Append("<cell>" & Server.HtmlEncode(myView(i)("callId")) & "</cell>")
      ret.Append("<cell>" & Server.HtmlEncode(myView(i)("callTime")) & "</cell>")
      ret.Append("<cell>" & Server.HtmlEncode(myView(i)("duration")) & "</cell>")

      ret.Append("</row>")
    Next

    ret.Append("</rows>")
    xmlRet.LoadXml(ret.ToString)
    Return xmlRet
   End Function

You can see I’m building the XML as a string and then loading it into the XMLDocumennt. I can’t say I know this is the best way. You could build the XML DOM directly on the document.

Method 3

Thanx a lot harlev…also for others one tip, you can set grid to work on client with

datatype: ‘clientside’

attribute. I didn’t find it at first because is not listed in online documentation but it is in pdf documentation which you can download from here.

Cheers

Method 4

For those to whom @Groxx’s solution didn’t work (when I tried it the content of my grid dissapeared every time I tried to sort a column), try the solution from this thread. It worked for me. I’m using jqGrid 4.5.4.

First, set loadonce : true in your grid’s settings. As explained here, this changes the datatype parameters to ‘local’ after the grids finishes loading for the first time. Then, when you want to reload the grid, change datatype back to json:

$('#your-grid').setGridParam({ datatype : 'json' }).trigger('reloadGrid');

If you are using navGrid you may want to review your add, edit and delete options to force your grid to reload like indicated in this answer.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0