Angular UI-grid not sorting by date

I am using UI-grid, and I have a bunch of JS date objects like so:

"dob": new Date('1942-11-19')

I want to be able to filter the column by date when you click the "sort ascending/descending" buttons. As such, I have set the colDef up like so:

      {
        field: 'dob'
        , displayName: 'D.O.B.'
        , width: '130'
        , editableCellTemplate: '<div><form name="inputForm"><input type="INPUT_TYPE" ng-class="\'colt\' + col.uid" ui-grid-editor ng-model="MODEL_COL_FIELD" style="border-bottom-color: #74B3CE; border-bottom-width: 2px;"></form></div>'
        , headerCellClass: $scope.highlightFilteredHeader
        , cellTemplate: '<div class="ui-grid-cell-contents" >{{grid.getCellValue(row, col)| date:\'MM-dd-yyyy\'}}</div>'
        , cellFilter: 'date'
        , type: 'date'
      },

however, the column simply does not sort correctly. I even tried to set up a function to sort it from an external button like so:

      function mostRecent(){
        console.log('clicked mostRecent');
        $scope.gridApi.grid.sortColumn(
          $scope.gridApi.grid.getColumn('dob'), uiGridConstants.DESC
        );
        $scope.gridApi.grid.notifyDataChange(uiGridConstants.dataChange.ALL); //this line updates the rest of the columns accordingly
      };

But it also causes a mish-mush sort that is not correct. Does anyone know what the issue is? I thought it might have to do with my cellTemplate, but after removing the template, there wasn't a difference...

Solution

Yes you are right, ui-grid doesn't support sorting of Date type columns.

However you can define a sortingAlgorithm in the columnDef.

Here is how your column definition should look like:

...

columnDefinition.sortingAlgorithm = function (firstDateString, secondDateString) {
  var dateFormat = 'YYYY-MM-DD';
  return function (firstDateString, secondDateString, dateFormat) {
    if (!firstDateString && !secondDateString) {
      return 0;
    }

    if (!firstDateString) {
      return 1;
    }

    if (!secondDateString) {
      return -1;
    }

    var firstDate = $window.moment(firstDateString, dateFormat);
    if (!firstDate.isValid()) {
      throw new Error('Invalid date: ', firstDateString);
    }

    var secondDate = $window.moment(secondDateString, dateFormat);
    if (!firstDate.isValid()) {
      throw new Error('Invalid date: ', secondDateString);
      }

    if (firstDate.isSame(secondDate)) {
      return 0;
    } else {
      return firstDate.isBefore(secondDate) ? -1 : 1;
    }
  };
};

...

Please note that in this example Moment.js is used. It is a very useful library so you might probably find also another place in your project where to use it.