Custom aggregate in EJ2 JavaScript Grid control

13 Apr 20239 minutes to read

To calculate the aggregate value with your own aggregate functions, use the custom aggregate option. To use custom aggregation, specify the type as Custom, and provide the custom aggregate function in the customAggregate property.

The custom aggregate function will be invoked with different arguments for total and group aggregations.

  • Total aggregation: The custom aggregate function will be called with the whole data and current AggregateColumn
    object.
  • Group aggregation: This will be called with the current group details and AggregateColumn object.
var customAggregateFn = function(data, aggColumn){
return data.result.filter(function(item) {
    return item[aggColumn.columnName] === 'Brazil';
  }).length;
} 

var grid = new ej.grids.Grid({
    dataSource: data,
    columns: [
        { field: 'OrderID', headerText: 'Order ID', textAlign: 'Right', width: 120 },
        { field: 'CustomerID', headerText: 'Customer ID', width: 150 },
        { field: 'Freight', headerText: 'Freight', width: 150, format: 'C2' },
        { field: 'ShipCountry', headerText: 'Ship Name', width: 150 }
    ],
    height: 268,
    aggregates: [{
        columns: [{
            type: 'Custom',
            customAggregate: customAggregateFn,
            columnName: 'ShipCountry',
            footerTemplate: 'Brazil Count: ${Custom}'
        }]
    }]
});
grid.appendTo('#Grid');
<!DOCTYPE html><html lang="en"><head>
    <title>EJ2 Grid</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript Grid Control">
    <meta name="author" content="Syncfusion">
    <link href="index.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-grids/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-navigations/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-lists/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-calendars/styles/material.css" rel="stylesheet">
    
    
    
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    
    

    
    
<script src="https://cdn.syncfusion.com/ej2/24.2.3/dist/ej2.min.js" type="text/javascript"></script>
<script src="es5-datasource.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="Grid"></div>

        <div id="toolbar-template">
            <div id="refresh" title="Refresh">
                <button class="e-btn e-flat">
                    <span class="e-btn-icon e-icons e-refresh"></span>
                </button>
            </div>
        </div>
    </div>



<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

To access the custom aggregate value inside the template, use the key as Custom.

Show the count of distinct values in aggregate row

You can calculate the aggregate value with your own aggregate functions. To use custom aggregation, specify the type as Custom, and provide the custom aggregate function in the customAggregate property.

In this below demo, we have show the count of distinct value for ShipCountry column by using custom aggregate.

ej.grids.Grid.Inject(ej.grids.Page, ej.grids.Aggregate);

var customAggregateFn = function() {
let results = new ej.data.DataManager(this.currentViewData).executeLocal(new ej.data.Query().select(['ShipCountry']));
let distinct = new ej.data.DataUtil.distinct(results, 'ShipCountry', true);
return distinct.length;
}

var grid = new ej.grids.Grid({
    dataSource: data,
    allowPaging: true,
    columns: [
        { field: 'OrderID', headerText: 'Order ID', textAlign: 'Right', width: 120, type: 'number' },
        { field: 'CustomerID', width: 140, headerText: 'Customer ID', type: 'string' },
        { field: 'Freight', headerText: 'Freight', textAlign: 'Right', width: 120, format: 'C2' },
        { field: "ShipCountry", headerText: "Ship Country", width: 150 }
    ],
    height: 220,
    aggregates: [{
        columns: [{
            type: 'Custom',
            customAggregate: customAggregateFn,
            columnName: 'ShipCountry',
            footerTemplate: 'Distinct Count: ${Custom}'
        }]
    }]
});
grid.appendTo('#Grid');
<!DOCTYPE html><html lang="en"><head>
    <title>EJ2 Grid</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript Grid Control">
    <meta name="author" content="Syncfusion">
    <link href="index.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-grids/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-navigations/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-lists/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-calendars/styles/material.css" rel="stylesheet">
    
    
    
    <link href="https://cdn.syncfusion.com/ej2/24.2.3/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    
    
    
    
<script src="https://cdn.syncfusion.com/ej2/24.2.3/dist/ej2.min.js" type="text/javascript"></script>
<script src="es5-datasource.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
    
    <div id="container">
        <div id="Grid"></div>        
    </div>

<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>