How to modify result data in EJ2 JavaScript Dropdown List

4 Sep 20263 minutes to read

When binding a remote data source, handle the actionComplete event to modify the result data before passing it to the DropDownList.

The following sample demonstrates how to modify the result data.

var ddlObject = new ej.dropdowns.DropDownList({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
    }),
    //bind the Query instance to query property
    query: new ej.data.Query().select(['ContactName']),
    //map the appropriate columns to fields property
    fields: { value: 'ContactName'},
    //set the placeholder to DropDownList input
    placeholder: "Find a customer",
     //sort the resulted items
    actionComplete: function (e) {
        // initially result contains 6 items
        console.log("Before modified the result: " + e.result.length);
        // remove first 2 items from result.
        e.result.splice(0, 2);
        // now displays the result count is 4.
        console.log("After modified the result: " + e.result.length);
    }
});

//render the component
ddlObject.appendTo('#ddlelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 DropDownList</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/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/34.2.2/dist/ej2.min.js" type="text/javascript"></script>
</head>

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


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