Filtering in EJ2 JavaScript 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.

var searchData = [
{ index: "s1", country: "Alaska" }, { index: "s2", country: "California" },
{ index: "s3", country: "Florida" }, { index: "s4", country: "Georgia" }
];

//initiates the component
var msObject = new ej.dropdowns.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) {
        let query = new ej.data.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);
    }
});

msObject.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/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/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:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id="select">
    </div>


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

var searchData = new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
});
var filter = new ej.dropdowns.MultiSelect({
    dataSource: searchData,
    query: new ej.data.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) => {
        // 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; }
          var query = new ej.data.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/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/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:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id="select">
    </div>


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

var searchData = new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
});
var filter = new ej.dropdowns.MultiSelect({
    dataSource: searchData,
    query: new ej.data.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) => {
        // load overall data when search key empty.
        if(e.text == '') e.updateData(sportsData);
        else{
          let query = new ej.data.Query().select(['sports', 'id']);
           //enable the case sensitive filtering by passing false to 4th parameter.
          query = (e.text !== '') ? query.where('sports', 'endswith', e.text, true) : 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/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/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:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id="select">
    </div>


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

var searchData = new ej.data.DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
});
var filter = new ej.dropdowns.MultiSelect({
    dataSource: searchData,
    query: new ej.data.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) => {
        // load overall data when search key empty.
        if(e.text == '') e.updateData(sportsData);
        else{
          let query = new ej.data.Query().select(['sports', 'id']);
           //enable the case sensitive filtering by passing false to 4th parameter.
          query = (e.text !== '') ? query.where('sports', 'startswith', e.text, true) : 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/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/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:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id="select">
    </div>


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

// create local data
    var data = [
        'Aeróbics',
        'Aeróbics en Agua',
        'Aerografía',
        'Aeromodelaje',
        'Águilas',
        'Ajedrez',
        'Ala Delta',
        'Álbumes de Música',
        'Alusivos',
        'Análisis de Escritura a Mano'];
    // initialize MultiSelect component
    var multiObj = new ej.dropdowns.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/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/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:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id="select">
    </div>


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

See Also