Filtering in EJ2 TypeScript Multi select control
2 May 202320 minutes to read
The MultiSelect has built-in support to filter data items when allowFiltering is enabled. The filter
operation starts as soon as you start typing characters in the MultiSelect input.
To display filtered items in the popup, filter the required data and return it to the MultiSelect via updateData method by using the filtering event.
The following sample illustrates how to query the data source and pass the data to the MultiSelect through the updateData method in filtering event.
import { MultiSelect, FilteringEventArgs } from '@syncfusion/ej2-dropdowns';
import { DataManager, Query } from '@syncfusion/ej2-data';
let searchData: { [key: string]: Object; }[] = [
{ index: "s1", country: "Alaska" }, { index: "s2", country: "California" },
{ index: "s3", country: "Florida" }, { index: "s4", country: "Georgia" }
];
let filter: MultiSelect = new MultiSelect({
dataSource: searchData,
// map the appropriate column
fields: { text: "country", value: "index" },
// set placeholder to MultiSelect input element
placeholder:"Select countries",
// set true to allowFiltering for enable filtering supports
allowFiltering: true,
//Bind the filter event
filtering: function (e: FilteringEventArgs) {
let query = new Query();
//frame the query based on search string with filter type.
query = (e.text != "") ? query.where("country", "startswith", e.text, true) : query;
//pass the filter data source, filter query to updateData method.
e.updateData(searchData, query);
}
});
filter.appendTo('#select');<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 MultiSelect</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/ej2/27.1.48/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-buttons/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<!--element which is going to render the MultiSelect-->
<input type="text" tabindex="1" id='select' />
</div>
</body>
</html>Limit the minimum filter character
When filtering the list items, you can set the limit for character count to raise remote request and fetch filtered data on the MultiSelect. This can be done by manual validation within the filter event handler.
In the following example, the remote request does not fetch the search data until the search key contains three characters.
import { MultiSelect, FilteringEventArgs } from '@syncfusion/ej2-dropdowns';
import { Query, DataManager, ODataV4Adaptor } from '@syncfusion/ej2-data';
let searchData: DataManager = new DataManager({
url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
adaptor: new ODataV4Adaptor,
crossDomain: true
});
let filter: MultiSelect = new MultiSelect({
dataSource: searchData,
query: new Query().select(['ContactName', 'CustomerID']).take(7),
// map the appropriate column
fields: { text: 'ContactName', value: 'CustomerID' },
// set placeholder to MultiSelect input element
placeholder:"Select customers",
//sort the resulted items
sortOrder: 'Ascending',
// set true to allowFiltering for enable filtering supports
allowFiltering: true,
//bind the filtering event handler
filtering: (e: FilteringEventArgs) => {
// load overall data when search key empty.
if(e.text == '') e.updateData(searchData);
else{
// restrict the remote request until search key contains 3 characters.
if (e.text.length < 3) { return; }
let query: Query = new Query().select(['ContactName', 'CustomerID']);
query = (e.text !== '') ? query.where('ContactName', 'startswith', e.text, true) : query;
e.updateData(searchData, query);
}
}
});
filter.appendTo('#select');<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 MultiSelect</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/ej2/27.1.48/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-buttons/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<!--element which is going to render the MultiSelect-->
<input type="text" tabindex="1" id='select' />
</div>
</body>
</html>Change the filter type
While filtering, you can change the filter type to contains, startsWith, or endsWith for string type within the filter event handler.
In the following examples, data filtering is done with endsWith type.
import { MultiSelect, FilteringEventArgs } from '@syncfusion/ej2-dropdowns';
import { Query, DataManager, ODataV4Adaptor } from '@syncfusion/ej2-data';
let searchData: DataManager = new DataManager({
url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
adaptor: new ODataV4Adaptor,
crossDomain: true
});
let filter: MultiSelect = new MultiSelect({
dataSource: searchData,
query: new Query().select(['ContactName', 'CustomerID']).take(7),
// map the appropriate column
fields: { text: 'ContactName', value: 'CustomerID' },
// set placeholder to MultiSelect input element
placeholder:"Select names",
// set true to allowFiltering for enable filtering supports
allowFiltering: true,
//set the height of the popup element
popupHeight: "250px",
//sort the resulted items
sortOrder: 'Ascending',
//bind the filtering event handler
filtering: (e: FilteringEventArgs) => {
// load overall data when search key empty.
if(e.text == '') e.updateData(searchData);
else{
let query: Query = new Query().select(['ContactName', 'CustomerID']);
// change the type of filtering
query = (e.text !== '') ? query.where('ContactName', 'endswith', e.text, true) : query;
e.updateData(searchData, query);
}
}
});
filter.appendTo('#select');<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 MultiSelect</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/ej2/27.1.48/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-buttons/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<!--element which is going to render the MultiSelect-->
<input type="text" tabindex="1" id='select' />
</div>
</body>
</html>Case sensitive filtering
Data items can be filtered either with or without case sensitivity using the DataManager. This can be done by passing the fourth optional parameter of the where clause.
The following example shows how to perform case-sensitive filter.
import { MultiSelect, FilteringEventArgs } from '@syncfusion/ej2-dropdowns';
let sportsData: { [key: string]: Object }[] = [
{ id: 'game1', sports: 'Badminton' },
{ id: 'game2', sports: 'Football' },
{ id: 'game3', sports: 'Tennis' },
{ id: 'game4', sports: 'Golf' },
{ id: 'game5', sports: 'Hockey' }
];
let filter: MultiSelect = new MultiSelect({
dataSource: sportsData,
// map the appropriate column
fields: { text: 'sports', value: 'id' },
// set placeholder to MultiSelect input element
placeholder:"Select names",
// set true to allowFiltering for enable filtering supports
allowFiltering: true,
//set the height of the popup element
popupHeight: "250px",
//sort the resulted items
sortOrder: 'Ascending',
//bind the filtering event handler
filtering: (e: FilteringEventArgs) => {
// load overall data when search key empty.
if(e.text == '') e.updateData(sportsData);
else{
let query: Query = new Query().select(['sports', 'id']);
//enable the case sensitive filtering by passing false to 4th parameter.
query = (e.text !== '') ? query.where('sports', 'startswith', e.text, false) : query;
e.updateData(sportsData, query);
}
}
});
filter.appendTo('#select');<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 MultiSelect</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/ej2/27.1.48/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-buttons/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<!--element which is going to render the MultiSelect-->
<input type="text" tabindex="1" id='select' />
</div>
</body>
</html>Diacritics Filtering
The MultiSelect supports diacritics filtering which will ignore the diacritics and makes it easier to filter the results in international characters lists when the ignoreAccent is enabled.
In the following sample,data with diacritics are bound as dataSource for MultiSelect.
import { MultiSelect } from '@syncfusion/ej2-dropdowns';
// create local data
let data: string[] = [
'Aeróbics',
'Aeróbics en Agua',
'Aerografía',
'Aeromodelaje',
'Águilas',
'Ajedrez',
'Ala Delta',
'Álbumes de Música',
'Alusivos',
'Análisis de Escritura a Mano'];
// initialize MultiSelect component
let multiObj: MultiSelect = new MultiSelect({
//set the local data to dataSource property
dataSource: data,
// set the placeholder to MultiSelect input element
placeholder: 'e.g: aero',
// enabled the ignoreAccent property for ignore the diacritics
ignoreAccent: true,
// set true for enable the filtering support.
allowFiltering: true
});
multiObj.appendTo('#select');<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 MultiSelect</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/ej2/27.1.48/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-dropdowns/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/27.1.48/ej2-buttons/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<br>
<!--element which is going to render the MultiSelect-->
<input type="text" tabindex="1" id='select' />
</div>
</body>
</html>