Es5 getting started in EJ2 JavaScript Combo box control

2 Jun 202322 minutes to read

The Essential JS 2 for JavaScript (global script) is an ES5 formatted pure JavaScript framework which can be directly used in latest web browsers.

Dependencies

The following list of dependencies are required to use the ComboBox component in your application.

|-- @syncfusion/ej2-dropdowns
    |-- @syncfusion/ej2-base
    |-- @syncfusion/ej2-data
    |-- @syncfusion/ej2-lists
    |-- @syncfusion/ej2-inputs
    |-- @syncfusion/ej2-navigations
    |-- @syncfusion/ej2-popups
        |-- @syncfusion/ej2-buttons

Component Initialization

The Essential JS 2 JavaScript components can be initialized by using either of the following ways.

Using local script and style references in a HTML page.
Using CDN link for script and style reference.

Using local script and style references in a HTML page

Step 1: Create an app folder myapp for Essential JS 2 JavaScript components.

Step 2: You can get the global scripts and styles from the Essential Studio JavaScript (Essential JS 2) build installed location.

Syntax:

Script: **(installed location)**/Syncfusion/Essential Studio/{RELEASE_VERSION}/Essential JS 2/{PACKAGE_NAME}/dist/global/{PACKAGE_NAME}.min.js

Styles: **(installed location)**/Syncfusion/Essential Studio/{RELEASE_VERSION}/Essential JS 2/{PACKAGE_NAME}/styles/material.css

Example:

Script: C:/Program Files (x86)/Syncfusion/Essential Studio/15.4.30/Essential JS 2/ej2-dropdowns/dist/global/ej2-dropdowns.min.js

Styles: C:/Program Files (x86)/Syncfusion/Essential Studio/15.4.30/Essential JS 2/ej2-dropdowns/styles/material.css

Step 3: Create a folder myapp/resources and copy/paste the global scripts and styles from the above installed location to myapp/resources location.

Step 4: Create a HTML page (index.html) in myapp location and add the Essentials JS 2 script and style references.

<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
       <head>
            <title>Essential JS 2</title>
            <!-- Essential JS 2 material theme -->
            <link href="resources/base/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/inputs/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/lists/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/popups/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/buttons/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>

            <!-- Essential JS 2 ComboBox's dependent scripts -->
            <script src="resources/ej2-base.min.js" type="text/javascript"></script>
            <script src="resources/ej2-data.min.js" type="text/javascript"></script>
            <script src="resources/ej2-inputs.min.js" type="text/javascript"></script>
            <script src="resources/ej2-lists.min.js" type="text/javascript"></script>
            <script src="resources/ej2-popups.min.js" type="text/javascript"></script>
            <script src="resources/ej2-buttons.min.js" type="text/javascript"></script>
            <!-- Essential JS 2 ComboBox's global script -->
            <script src="resources/ej2-dropdowns.min.js" type="text/javascript"></script>
       </head>
       <body>
       </body>
  </html>

Step 5: Now, add the input element and initiate the Essential JS 2 ComboBox component in the index.html by using following code

<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
       <head>
            <title>Essential JS 2</title>
            <!-- Essential JS 2 material theme -->
            <link href="resources/base/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/inputs/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/lists/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/popups/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/buttons/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="resources/dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>

            <!-- Essential JS 2 ComboBox's dependent scripts -->
            <script src="resources/ej2-base.min.js" type="text/javascript"></script>
            <script src="resources/ej2-data.min.js" type="text/javascript"></script>
            <script src="resources/ej2-inputs.min.js" type="text/javascript"></script>
            <script src="resources/ej2-lists.min.js" type="text/javascript"></script>
            <script src="resources/ej2-popups.min.js" type="text/javascript"></script>
            <script src="resources/ej2-buttons.min.js" type="text/javascript"></script>
            <!-- Essential JS 2 ComboBox's global script -->
            <script src="resources/ej2-dropdowns.min.js" type="text/javascript"></script>
       </head>
      <body>
           <!-- Add the HTML <input> element  -->
             <input type="text" id='comboelement' />
            <script>
            // initialize ComboBox component
            var comboBox = new ej.dropdowns.ComboBox();
            // Render initialized ComboBox.
            comboBox.appendTo('#comboelement');
            </script>
       </body>
  </html>

Step 6: Now, run the index.html in web browser, it will render the Essential JS 2 ComboBox component.

Using CDN link for script and style reference

Step 1: Create an app folder myapp for the Essential JS 2 JavaScript components.

Step 2: The Essential JS 2 component’s global scripts and styles are already hosted in the below CDN link formats.

Syntax:

Script: http://cdn.syncfusion.com/ej2/{PACKAGE_NAME}/dist/global/{PACKAGE_NAME}.min.js

Styles: http://cdn.syncfusion.com/ej2/{PACKAGE_NAME}/styles/material.css

Example:

Script: http://cdn.syncfusion.com/ej2/ej2-dropdowns/dist/global/ej2-dropdowns.min.js

Styles: http://cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css

Step 3: Create a HTML page (index.html) in myapp location and add the CDN link references. Now, add the input element and initiate the Essential JS 2 ComboBox component in the index.html by using following code.

index.html
<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
        <title>Essential JS 2</title>
        <!-- Essential JS 2 material theme -->
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>
        <!-- Essential JS 2 all script -->
        <!-- <script src="https://cdn.syncfusion.com/ej2/27.2.2/dist/ej2.min.js" type="text/javascript"></script> -->

        <!-- Essential JS 2 ComboBox's dependent scripts -->
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/dist/global/ej2-base.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-data/dist/global/ej2-data.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/dist/global/ej2-inputs.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/dist/global/ej2-buttons.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-lists/dist/global/ej2-lists.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/dist/global/ej2-popups.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/dist/global/ej2-dropdowns.min.js" type="text/javascript"></script>
   <script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
   <body>
       <!-- Add the HTML <input> element  -->
         <input type="text" id='comboelement' />
        <script>
        var sportsData = ['Badminton', 'Basketball', 'Cricket', 'Football', 'Golf', 'Gymnastics', 'Hockey', 'Rugby', 'Snooker', 'Tennis'];
        // initialize ComboBox component
        var comboBox = new ej.dropdowns.ComboBox({
            dataSource: sportsData,
        });
        // Render initialized ComboBox.
        comboBox.appendTo('#comboelement');
        </script>
   </body>
  </html>

Step 4: Now, run the index.html in web browser, it will render the Essential JS 2 ComboBox component.

Binding data source

After initializing, populate the ComboBox with data using the dataSource property. Here, an array of string values is passed to the ComboBox component.

<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
       <head>
            <title>Essential JS 2</title>
            <!-- Essential JS 2 material theme -->
            <link href="//cdn.syncfusion.com/ej2/ej2-base/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet" type="text/css"/>
            <link href="//cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>
            <!-- Essential JS 2 all script -->
            <!-- <script src="https://cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script> -->

            <!-- Essential JS 2 ComboBox's dependent scripts -->
            <script src="//cdn.syncfusion.com/ej2/ej2-base/dist/global/ej2-base.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-data/dist/global/ej2-data.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-inputs/dist/global/ej2-inputs.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-buttons/dist/global/ej2-buttons.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-lists/dist/global/ej2-lists.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-popups/dist/global/ej2-popups.min.js" type="text/javascript"></script>
            <script src="//cdn.syncfusion.com/ej2/ej2-dropdowns/dist/global/ej2-dropdowns.min.js" type="text/javascript"></script>
       </head>
       <body>
           <!-- Add the HTML <input> element  -->
             <input type="text" id='comboelement' />
            <script>
            var sportsData = ['Badminton', 'Basketball', 'Cricket', 'Football', 'Golf', 'Gymnastics', 'Hockey', 'Rugby', 'Snooker', 'Tennis'];
            // initialize ComboBox component
            var comboBox = new ej.dropdowns.ComboBox({
                dataSource: sportsData,
            });
            // Render initialized ComboBox.
            comboBox.appendTo('#comboelement');
            </script>
       </body>
  </html>

Custom values

The ComboBox allows the user to give input as custom value which is not required to present in predefined set of values. By default, this support is enabled by allowCustom property. In this case, both text field and value field considered as same.
The custom value will be sent to post back handler when a form is about to be submitted.

index.html
<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
                
        <title>Essential JS 2</title>
        <!-- Essential JS 2 material theme -->
         <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>
       <!-- Essential JS 2 all script -->
        <!-- <script src="https://cdn.syncfusion.com/ej2/27.2.2/dist/ej2.min.js" type="text/javascript"></script> -->

        <!-- Essential JS 2 ComboBox's dependent scripts -->
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/dist/global/ej2-base.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-data/dist/global/ej2-data.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/dist/global/ej2-inputs.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/dist/global/ej2-buttons.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-lists/dist/global/ej2-lists.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/dist/global/ej2-popups.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/dist/global/ej2-dropdowns.min.js" type="text/javascript"></script>
   <script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
   <body>
       <!-- Add the HTML <input> element  -->
         <input type="text" id='comboelement' />
        <script>
        let sportsData = [
            { Id: 'Game1', Game: 'Badminton' },
            { Id: 'Game2', Game: 'Basketball' },
            { Id: 'Game3', Game: 'Cricket' },
            { Id: 'Game4', Game: 'Football' },
            { Id: 'Game5', Game: 'Golf' },
            { Id: 'Game6', Game: 'Hockey' },
            { Id: 'Game7', Game: 'Rugby' },
            { Id: 'Game8', Game: 'Snooker' }
        ];
        // initialize ComboBox component
        var listObj = new ej.dropdowns.ComboBox({
        //set the data to dataSource property
            dataSource: sportsData,
            // By default, its enabled. For your better understanding, showcase this property.
            allowCustom: true,
            // maps the appropriate column to fields property
            fields: { value: 'Game' },
            // set placeholder to ComboBox input element
            placeholder: "Find a game"});
        listObj.appendTo('#comboelement');
        </script>
   </body>
  </html>

By default, the width of the popup list automatically adjusts according to the ComboBox input element’s width, and the height of the popup list has ‘300px’.

The height and width of the popup list can also be customized using the popupHeight and popupWidth properties respectively.

In the following sample, popup list’s width and height are configured.

index.html
<!DOCTYPE html>
  <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
                
        <title>Essential JS 2</title>
        <!-- Essential JS 2 material theme -->
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet" type="text/css"/>
        <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/styles/material.css" rel="stylesheet" type="text/css"/>
       <!-- Essential JS 2 all script -->
        <!-- <script src="https://cdn.syncfusion.com/ej2/27.2.2/dist/ej2.min.js" type="text/javascript"></script> -->

        <!-- Essential JS 2 ComboBox's dependent scripts -->
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/dist/global/ej2-base.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-data/dist/global/ej2-data.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/dist/global/ej2-inputs.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/dist/global/ej2-buttons.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-lists/dist/global/ej2-lists.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/dist/global/ej2-popups.min.js" type="text/javascript"></script>
        <script src="//cdn.syncfusion.com/ej2/21.2.3/ej2-dropdowns/dist/global/ej2-dropdowns.min.js" type="text/javascript"></script>
   <script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
   <body>
       <!-- Add the HTML <input> element  -->
         <input type="text" id='comboelement' />
        <script>
        var sportsData = ['Badminton', 'Basketball', 'Cricket', 'Football', 'Golf', 'Gymnastics', 'Hockey', 'Rugby', 'Snooker', 'Tennis'];
        // initialize ComboBox component
        var listObj = new ej.dropdowns.ComboBox({
        //set the data to dataSource property
            dataSource: sportsData,
            //set width to suggestion list
            popupWidth: '250px',
            // set the popup list height
            popupHeight: "250px",
            // set placeholder to ComboBox input element
            placeholder: "Find a game"});
        listObj.appendTo('#comboelement');
        </script>
   </body>
  </html>