When binding the remote data source, by using the actionComplete event, you can modify the result data before passing it to DropDownList.
The following sample demonstrate how to modify the result data.
import { DropDownList } from '@syncfusion/ej2-dropdowns';
//import DataManager related classes
import { Query, DataManager, ODataV4Adaptor } from '@syncfusion/ej2-data';
//initiates the component
let customers: DropDownList = new DropDownList({
//bind the DataManager instance to dataSource property
dataSource: new DataManager({
url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
adaptor: new ODataV4Adaptor,
crossDomain: true
}),
//bind the Query instance to query property
query: new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6),
//map the appropriate columns to fields property
fields: { text: 'ContactName', value: 'CustomerID' },
//set the placeholder to DropDownList input
placeholder:"Select a customer",
//sort the resulted items
actionComplete: function (e: any) {
// 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
customers.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="//cdn.syncfusion.com/ej2/21.1.35/ej2-base/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/21.1.35/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/21.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
<script src="systemjs.config.js"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<input type="text" id='ddlelement' />
</div>
</body>
</html>