$(() => {
const MILLISECONDS_IN_DAY = 1000 * 60 * 60 * 24;
let dataGrid;
$('#grid-container').dxDataGrid({
dataSource: {
store: {
type: 'odata',
url: 'https://js.devexpress.com/Demos/DevAV/odata/Tasks',
key: 'Task_ID',
},
expand: 'ResponsibleEmployee',
select: [
'Task_ID',
'Task_Subject',
'Task_Start_Date',
'Task_Due_Date',
'Task_Status',
'ResponsibleEmployee/Employee_Full_Name',
],
},
selection: {
mode: 'multiple',
deferred: true,
},
filterRow: {
visible: true,
},
onInitialized(e) {
dataGrid = e.component;
calculateStatistics();
},
selectionFilter: ['Task_Status', '=', 'Completed'],
showBorders: true,
columns: [{
caption: 'Subject',
dataField: 'Task_Subject',
}, {
caption: 'Start Date',
dataField: 'Task_Start_Date',
width: 'auto',
dataType: 'date',
}, {
caption: 'Due Date',
dataField: 'Task_Due_Date',
width: 'auto',
dataType: 'date',
}, {
caption: 'Assigned To',
dataField: 'ResponsibleEmployee.Employee_Full_Name',
width: 'auto',
allowSorting: false,
}, {
caption: 'Status',
width: 'auto',
dataField: 'Task_Status',
}],
}).dxDataGrid('instance');
function calculateStatistics() {
dataGrid.getSelectedRowsData().then((rowData) => {
let commonDuration = 0;
for (let i = 0; i < rowData.length; i += 1) {
commonDuration += rowData[i].Task_Due_Date - rowData[i].Task_Start_Date;
}
commonDuration /= MILLISECONDS_IN_DAY;
$('#tasks-count').text(rowData.length);
$('#people-count').text(
DevExpress.data.query(rowData)
.groupBy('ResponsibleEmployee.Employee_Full_Name')
.toArray()
.length,
);
$('#avg-duration').text(Math.round(commonDuration / rowData.length) || 0);
});
}
$('#calculateButton').dxButton({
text: 'Get statistics on the selected tasks',
type: 'default',
onClick: calculateStatistics,
});
});
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>DevExtreme Demo</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>window.jQuery || document.write(decodeURIComponent('%3Cscript src="js/jquery.min.js"%3E%3C/script%3E'))</script>
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/22.1.3/css/dx.common.css" />
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/22.1.3/css/dx.light.css" />
<script src="https://cdn3.devexpress.com/jslib/22.1.3/js/dx.all.js"></script>
<link rel="stylesheet" type="text/css" href="styles.css" />
<script src="index.js"></script>
</head>
<body class="dx-viewport">
<div class="demo-container">
<div id="grid-container"></div>
<div class="selection-summary center">
<div id="calculateButton"></div>
<div>
<div class="column">
<span class="text count">Task count:</span>
<span class="value" id="tasks-count">0</span>
</div>
<div class="column">
<span class="text people-count">People assigned:</span>
<span class="value" id="people-count">0</span>
</div>
<div class="column">
<span class="text avg-duration"> Average task duration (days): </span>
<span class="value" id="avg-duration">0</span>
</div>
</div>
</div>
</div>
</body>
</html>
#grid-container {
height: 400px;
}
.center {
text-align: center;
}
.selection-summary {
border: 1px solid rgba(161, 161, 161, 0.2);
padding: 25px;
}
.column {
margin: 20px 30px 0 0;
display: inline-block;
white-space: nowrap;
text-align: right;
}
.value {
font-size: 40px;
display: inline-block;
vertical-align: middle;
}
.text {
text-align: left;
white-space: normal;
display: inline-block;
vertical-align: middle;
}
.avg-duration {
width: 100px;
}
.count {
width: 40px;
}
.people-count {
width: 65px;
}
