Sorting jqGrid in ASP.NET MVC client view with jQuery and LINQ-to-Entities

Question

I'm a jQuery noob, so I'm sure I'm missing something simple here.

I've got the jqGrid working with an action that creates JSON data from a LINQ-to-Entities operation. But when I click on the column headers in the browser, the rows don't sort. The ascending/descending indicator shows up, but nothing else happens.

The necessary JavaScript and CSS links are in the master page header:

<script src="/Scripts/jquery-1.3.2.min.js" type="text/javascript"></script>
<!-- CSS and JavaScript files for jqGrid to display on Details pages -->
<link rel="stylesheet" type="text/css" href="/scripts/jQuery/jqGrid-3.4.4/themes/green/grid.css" title="green" media="screen" />
<script src="/Scripts/jQuery/jqGrid-3.4.4/jquery.jqGrid.js" type="text/javascript"></script>
<script src="/Scripts/jQuery/jqGrid-3.4.4/js/jqModal.js" type="text/javascript"></script>
<script src="/Scripts/jQuery/jqGrid-3.4.4/js/jqDnR.js" type="text/javascript"></script>

Here's my initialization code:

// jqGrid setup.
$("#gridlist").jqGrid({
    url: '/Contact/GridData',
    datatype: 'json',
    mtype: 'GET',
    colNames: ['ID', 'First Name', 'Last Name', 'Organization'],
    colModel: [
        { name: 'id', index: 'id', width: 40, align: 'left', resizable: true },
        { name: 'first_name', index: 'first_name', width: 200, align: 'left', resizable: true, sortable: true, sorttype: "text" },
        { name: 'last_name', index: 'last_name', width: 200, align: 'left', resizable: true, sortable: true, sorttype: "text" },
        { name: 'organization', index: 'organization', width: 300, align: 'left', resizable: true, sortable: true, sorttype: "text"}],
    pager: jQuery('#pager'),
    rowNum: 5,
    rowList: [5, 10, 20, 50],
    repeatitems: false,
    viewrecords: true,
    imgpath: '/scripts/jQuery/jqGrid-3.4.4/themes/green/images',
    caption: 'Contacts'
});                  

And here's the HTML:

    <h3>My Grid Data</h3>
    <table id="gridlist" class="scroll" cellpadding="0" cellspacing="0">
    </table>
    <div id="pager" class="scroll" style="text-align:center;">
    </div>

And, just for completeness, the action method:

public ActionResult GridData()
{
    var page = new { page = 1 };

    IEnumerable contacts = _db.ContactSet;
    int i = 0;
    var rows = new object[contacts.Count()];

    foreach (Contact contact in contacts)
    {
        rows[i] = new { id = contact.ID, cell = new[] { contact.ID.ToString(), contact.First_Name, contact.Last_Name, contact.Organization } };
        i++;
    }

    var result = new JsonResult();
    result.Data = new { page = 1, records = 2, rows, total = 1 };

    return result;
}

Any ideas what obvious setting I'm missing here?

Solution 1

There are two basic ways to handle this. The grid can sort the data itself. I can't remember how to turn this on, because I never use this option. Generally, I work with datasets which are too large to return to the page, so I use the grid's paging features. This requires doing this sort on the server, since the grid will not see the entire dataset.

To do the paging on the server, add a sidx and a sord (both strings) argument to your action. sidx will be the name of the column to sort on. sord will be the direction, asc or desc.

I have a demo project which shows how to do this (using LINQ to Objects). But using LINQ to Entities is almost identical; I use LINQ to Entities in my production/non-demo code. Download the demo solution and look for yourself.

Solution 2

OK, I should have posted this when I figured it out, but I ended up getting caught up in other tasks. Here is what I did that worked with LINQ to Entities, implemented for a report entity. First, the code to load the jqGrid with a default search was simple (once I figured out what I had missed):

$(document).ready(function() {

    // Set up jqGrid for the report search results table.
    // This is displayed in a tab in the bottom section of the master page.
    $("#searchResultList").jqGrid({
        url: '/Report/GetResultsL2E/',
        datatype: 'json',
        mtype: 'GET',
        colNames: ['', 'ID', 'Title', 'Post_Date', 'Start_Date', 'End_Date', 'Summary'],
        colModel: [
          { name: 'act', index: 'act', width: 75, sortable: false },
          { name: 'ID', index: 'ID', width: 40, align: 'left', hidden: true },
          { name: 'Title', index: 'Title', width: 150, align: 'left' },
          { name: 'Post_Date', index: 'Post_Date', width: 80, align: 'left', formatter: 'date' },
          { name: 'Start_Date', index: 'Start_Date', width: 80, align: 'left', formatter: 'date' },
          { name: 'End_Date', index: 'End_Date', width: 80, align: 'left', formatter: 'date' },
          { name: 'Summary', index: 'Summary', width: 240, align: 'left' }
        ],
        pager: jQuery('#searchResultPager'),
        rowNum: 10,
        rowList: [5, 10, 20, 50],
        sortname: 'Title',
        sortorder: "asc",
        viewrecords: true,
        imgpath: '/Scripts/jqGrid/themes/green/images',
        caption: 'Report Search Results', 
        editurl: "/Report/Edit",
        scroll: true,
        height: 'auto',
        recordtext: ' Reports',
        pgtext: ' of ',
        multiselect: true, 
        multiboxonly: true, //adds check box column
        altRows: true,
        loadComplete: function() {
            var ids = jQuery("#searchResultList").getDataIDs();
            for (var i = 0; i ";
                se = "";
                ce = "";
                jQuery("#searchResultList").setRowData(ids[i], { act: be + se + ce })
            }
        }
    }).navGrid('#searchResultPager',
    { edit: false, add: false, del: false, search: false }, //options 
    {height: 280, reloadAfterSubmit: false }, // edit options 
    {height: 280, reloadAfterSubmit: false }, // add options 
    {reloadAfterSubmit: false }, // del options 
    {} // search options 
    );
});

The method to load the default search set returns the first page of the total set of reports available:

/// 
/// Query the ReportSet to return a paged, sorted set of Report entity properties in response to a call from a view.
/// 
/// The name of the column to use for sorting.
/// The order of the sort (ascending or descending).
/// The number of the page to return to the calling process.
/// The number of rows to return for the page.
/// This ActionResult returns a JSON result to be used by a jqGrid using the jQuery library.
/// jQuery requires a script tag linking the jQuery.js script.
/// jqGrid requires stylesheet links to the following scripts and stylesheets:
/// 
/// jQuery/themes/base/ui.all.css
/// jqGrid/themes/green/grid.css (or other theme CSS file)
/// jqGrid/jquery.jqGrid.js
/// jqGrid/grid.base.js
/// jqGrid/js/jqModal.js
/// jqGrid/js/jqDnR.js
/// 
public ActionResult GetResultsL2E(string sidx, string sord, int page, int rows)
{
    int pageIndex = Convert.ToInt32(page) - 1;
    int pageSize = rows;
    int totalRecords = _db.ReportSet.Count();
    int totalPages = (int)Math.Ceiling((float)totalRecords / (float)pageSize);
    int startRecord = pageIndex * pageSize;

    List rowStrings = new List();
    // Get all of the reports in the model in a fixed order (for comparison).
    //var reports = from item in _db.ReportSet
    //              orderby item.Start_Date, item.Title
    //              select new { item.ID, item.Title, item.Post_Date, 
    //              item.Start_Date, item.End_Date, item.Summary };
    // Get all of the reports in the model in a dynamic order passed from jqGrid.
    string orderBytext = "";
    orderBytext = string.Format("it.{0} {1}", sidx, sord);
    var reports = _db.ReportSet
                   .OrderBy(orderBytext);

    List stringList = new List();

    int counter = reports.Count();
    foreach (var report in reports)
    {
        var rowString = new
        {
            id = report.ID,
            cell = new[] {
                    "",
                    report.ID.ToString(),
                    report.Title,
                    report.Post_Date.ToShortDateString(),
                    report.Start_Date.ToShortDateString(),
                    report.End_Date.ToString(),
                    report.Summary.ToString()}
        };
        stringList.Add(rowString);
    }

    var rowsOut = new object[counter];
    for (int i = 0; i 

I later added another method to respond to the user selecting columns to sort, using the PredicateBuilder discussed from the Albaharis' book C# in a Nutshell's section on Dynamically Composing Expression Predicates. I discussed my solution to that in a question I started on MSDN at PredicateBuilder fails on nested predicates with LINQ to Entities