Templates in EJ2 JavaScript Combo box control

2 May 202318 minutes to read

The ComboBox has been provided with several options to customize each list item, group title, selected value, header, and footer elements. It uses the Essential JS 2 Template engine to compile and render the elements properly.

Item template

The content of each list item within the ComboBox can be customized with the help of itemTemplate property.

In the following sample, each list item is split into two columns to display relevant data’s.

index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
    }),
    //bind the Query instance to query property
    query: new ej.data.Query().from('Employees').select(['FirstName', 'City','EmployeeID']).take(6),
    //map the appropriate columns to fields property
    fields: { value: 'FirstName' },
    //set the placeholder to ComboBox input
    placeholder:"Select an employee",   
    //sort the resulted items
    sortOrder: 'Ascending',
    //set the value to itemTemplate property
    itemTemplate: "<span><span class='name'>${FirstName}</span><span class ='city'>${City}</span></span>"
});

//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <input type="text" id="comboelement">
    </div>


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

Group template

The group header title under which appropriate sub-items are categorized can also be customize with the help of groupTemplate property. This template is common for both inline and floating group header template.

In the following sample, employees are grouped according to their city.

index.js
index.html
var groupPredicate = new ej.data.Predicate('City', 'equal','london').or('City','equal','seattle');
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
    }),
    //bind the Query instance to query property
    query: new ej.data.Query().from('Employees').select(['FirstName', 'City','EmployeeID']).take(6).where(groupPredicate),
    //map the appropriate columns to fields property
    fields: { value: 'FirstName', groupBy: 'City'},
    //set the placeholder to ComboBox input
    placeholder:"Select an employee",   
    //sort the resulted items
    sortOrder: 'Ascending',
    //set the value to groupTemplate
    groupTemplate: "<strong>${City}</strong>"
});

//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <input type="text" id="comboelement">
    </div>


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

Header template

The header element is shown statically at the top of the popup list items within the ComboBox, and any custom element can be placed as a header element using the headerTemplate property.

In the following sample, the list items and its headers are designed and displayed as two columns similar to multiple columns of the grid.

index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
    }),
    //bind the Query instance to query property
    query: new ej.data.Query().from('Employees').select(['FirstName', 'City','EmployeeID']).take(6),
    //map the appropriate columns to fields property
    fields: { value: 'FirstName'},
    //set the placeholder to ComboBox input
    placeholder:"Select an employee",   
    //sort the resulted items
    sortOrder: 'Ascending',
    //set the value to headerTemplate
    headerTemplate: "<span class='head'><span class='name'>Name</span><span class='city'>City</span></span>",
    //set the value to item template
    itemTemplate: "<span class='item' ><span class='name'>${FirstName}</span><span class='city'>${City}</span></span>"
});

//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <input type="text" id="comboelement">
    </div>


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

The ComboBox has options to show a footer element at the bottom of the list items in the popup list. Here, you can place any custom element as a footer element using the footerTemplate property.

In the following sample, footer element displays the total number of list items present in the ComboBox.

index.js
index.html
var sportsData = [ "Basketball", "Cricket", "Football", "Golf"];
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: sportsData ,
    //set the placeholder to ComboBox input
    placeholder:"Select games",
    //set the value to footer template
    footerTemplate:"<span class='foot'> Total list items: "+ sportsData.length +"</span>"
});
 
//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        
        <input type="text" id="comboelement">
    </div>


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

No records template

The ComboBox is provided with support to custom design the popup list content when no data is found and no matches found on search with the help of noRecordsTemplate property.

In the following sample, popup list content displays the notification of no data available.

index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: [],
    //set the placeholder to ComboBox input
    placeholder:"Select an item",
    //set the value to noRecords template
    noRecordsTemplate:"<span class='norecord'> NO DATA AVAILABLE</span>"
}); 
//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <input type="text" tabindex="1" id="comboelement">
    </div>


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

Action failure template

There is also an option to custom design the popup list content when the data fetch request fails at the remote server. This can be achieved using the actionFailureTemplate property.

In the following sample, when the data fetch request fails, the ComboBox displays the notification.

index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            // Here, use the wrong url to display the action failure template
            url: 'https://services.odata.org/V4/Northwind/Northwind.svcs/',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
    }),
    //bind the Query instance to query property
    query: new ej.data.Query().from('Employees').select(['FirstName']).take(6),
    //map the appropriate columns to fields property
    fields: { text: 'FirstName', value: 'EmployeeID' },
    //set the placeholder to ComboBox input
    placeholder:"Select an employee",
    //set the value to action failure template
    actionFailureTemplate:"<span class='action-failure'> Data fetch get fails</span>"

});
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript UI Controls">
    <meta name="author" content="Syncfusion">
    <link href="styles.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/28.1.33/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/28.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <input type="text" tabindex="1" id="comboelement">
    </div>


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