jqgrid select only one row per group

Question

How can we allow the users to only select one row per group?

I have the following code.

var data = [
           { ActionItemId: "AAZ08702-0001104", StrarTime: "2007-10-01", Category: "General", CategoryDetails: "dummy text of industry. a galley of type ", TargetCategory: "200.00",
            TargetDateCategory: "10.00", ActualCategory: "210.00"}
        ];

        $("#jqGrid").jqGrid({
            data: data,
            datatype: "local",
            colModel: [
                { label: 'Action Item ID', name: 'ActionItemId',  key: true },
                { label: 'Start Time', name: 'StrarTime'},
                { label: 'Category', name: 'Category'},
                { label: 'Details', name: 'CategoryDetails', cellattr: function (rowId, tv, rawObject, cm, rdata) { return 'style="white-space: normal;"' }},
                { label: 'Target <Category>', name: 'TargetCategory' },
                { label: 'Target Date <Category>', name: 'TargetDateCategory'}
            ],
            loadonce: true,
            viewrecords: true,
            //width: 1000,
            height: 400,
            rowNum: 20,
            rowList: [20, 30, 50],
            rownumbers: true,
            rownumWidth: 25,
            multiselect: true,
            shrinkToFit: false,
            pager: "#jqGridPager",
            grouping: true,
            groupingView: {
                groupField: ["Category"],
                groupColumnShow: [true],
                groupText: ["Category: <b>{0}</b>"],
                groupOrder: ["asc"],
                groupSummary: [false],
                groupCollapse: false

            }
        });

I need to disable the ability to select multiple rows per column. is it possible?

Is there a setting in the grouping function to enable which will work as mu requirement? or should it be custom development?

Note: I have only added one column to avoid a very long code in the question

Answer 1

One of the possible implementation could be adding add callback which return false if another row from the same group is already selected. An example of the implementation is the following:

beforeSelectRow: function (rowid, e) {
    var selarrrow = $(this).jqGrid("getGridParam", "selarrrow"),
        $tr = $(e.target).closest("tr.jqgrow"),
        otherIdsOfTheGroup;

    if ($tr.length > 0) {
        otherIdsOfTheGroup =
            // get all rows of the group before the current
            $tr.prevUntil("tr.jqgroup")
                // add all rows of the group after the current
                .add($tr.nextUntil("tr.jqgroup"))
                // enum all the rows of the group without the current
                .map(function () {
                    // test whether the rowid is already selected
                    if ($.inArray(this.id, selarrrow) >= 0) {
                        // add the rowid to the array of returned values
                        return this.id;
                    }
                });
        // otherIdsOfTheGroup contains the array of rowids of the rows
        // from the same group, which are already selected
        if (otherIdsOfTheGroup.length > 0) {
            return false; // prevent selection
        }
    }
    return true; // allow selection
}

See the demo

UPDATED: One can easy modify the aboce vode to unselect the previously selected rows from the same group. One need just call resetSelection for every rowid from otherIdsOfTheGroup array and return true from otherIdsOfTheGroup to allow selection:

beforeSelectRow: function (rowid, e) {
    var $this = $(this),
        selarrrow = $this.jqGrid("getGridParam", "selarrrow"),
        $tr = $(e.target).closest("tr.jqgrow"),
        otherIdsOfTheGroup;

    if ($tr.length > 0) {
        otherIdsOfTheGroup =
            // get all rows of the group before the current
            $tr.prevUntil("tr.jqgroup")
                // add all rows of the group after the current
                .add($tr.nextUntil("tr.jqgroup"))
                // enum all the rows of the group without the current
                .map(function () {
                    // test whether the rowid is already selected
                    if ($.inArray(this.id, selarrrow) >= 0) {
                        // add the rowid to the array of returned values
                        return this.id;
                    }
                });
        // otherIdsOfTheGroup contains the array of rowids of the rows
        // from the same group, which are already selected
        if (otherIdsOfTheGroup.length > 0) {
            $.each(otherIdsOfTheGroup, function () {
                $this.jqGrid("resetSelection", this);
            });
        }
    }
    return true; // allow selection
}

See the next demo. I included hiding of the column header of "Select All" button just to write less code. You can implement onSelectAll callback and allow to select only one (for example the first) row from every group.

Answer 2

I managed to solve this issue using the following code.

        beforeSelectRow: function (id, e) {
            var rowdata = $("#jqGrid").getRowData(id);
            var category = rowdata.Category;
            var selectedRowTR = $("#jqGrid").find("tr[id='" + id + "']");
            var groupTRs = $("#jqGrid").find("tbody> tr.jqgrow > td[title='" + category + "']").parents("tr");

            var ids = groupTRs.map(function () {
                return this.id;
            }).get();

            var selectedIDs = $("#jqGrid").getGridParam("selarrrow");

            var commonValues = [];
            var i, j;
            var arr1Length = ids.length;
            var arr2Length = selectedIDs.length;

            for (i = 0; i < arr1Length; i++) {
                for (j = 0; j < arr2Length; j++) {
                    if (ids[i] === selectedIDs[j]) {
                        commonValues.push(ids[i]);
                    }
                }
            }

            for (var i = 0; i < commonValues.length; i++) {
                $("#jqGrid").jqGrid('setSelection', commonValues[i], false);

            }

        return true;
    },

rowdata.Category; is the variable which the table is grouped. The only issue is that the user cannot untick what he/she has already selected in a group. so it works like a radio button set. But it works for my requirement. hopefully we can improve this and introduce radio kind of behavior for grouping in jqgrid. thanks everyone.