Search results

Filtering

The ComboBox 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 component.

To display filtered items in the popup, filter the required data and return it to the ComboBox via updateData method by using the filtering event.

The following sample illustrates how to query the data source and pass the data to the ComboBox through the updateData method in filtering event.

Source
Preview
index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
    //bind the data manager instance to dataSource property
    dataSource: new ej.data.DataManager({
            url: 'http://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 ComboBox input
    placeholder: "Find a customer",
    //set the filterType to searching operation
    filterType: 'StartsWith',
    //sort the resulted items
    sortOrder: 'Ascending'
});

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

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <br>
        <input type="text" id="comboelement">
    </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 ComboBox. 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.

Source
Preview
index.js
index.html
//initiates the component
var searchData = new ej.data.DataManager({
            url: 'http://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
});
var comboBoxObject = new ej.dropdowns.ComboBox({
    dataSource: searchData,
    query: new ej.data.Query().select(['ContactName', 'CustomerID']).take(7),
    // map the appropriate column
    fields: { text: 'ContactName', value: 'CustomerID' },
    // set placeholder to ComboBox 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);
        }
    }
});
//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</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/ej2-base/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="//cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <br>
        <input type="text" id="comboelement">
    </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.

Source
Preview
index.js
index.html
//initiates the component
var comboBoxObject = new ej.dropdowns.ComboBox({
      dataSource: searchData,
    query: new ej.data.Query().select(['ContactName', 'CustomerID']).take(7),
    // map the appropriate column
    fields: { text: 'ContactName', value: 'CustomerID' },
    // set placeholder to ComboBox 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{ 
          var query = new ej.data.Query().select(['ContactName', 'CustomerID']);
          // change the type of filtering to endswith filtering
          query = (e.text !== '') ? query.where('ContactName', 'endswith', e.text, true) : query;
          e.updateData(searchData, query);
        }
    }
});

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

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <br>
        <input type="text" id="comboelement">
    </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.

Source
Preview
index.js
index.html
//initiates the component
var searchData = new ej.data.DataManager({
            url: 'http://services.odata.org/V4/Northwind/Northwind.svc/Customers',
            adaptor: new ej.data.ODataV4Adaptor(),
            crossDomain: true
});
var comboBoxObject = new ej.dropdowns.ComboBox({
    dataSource: searchData,
    query: new ej.data.Query().select(['ContactName', 'CustomerID']).take(7),
    // map the appropriate column
    fields: { text: 'ContactName', value: 'CustomerID' },
    // set placeholder to ComboBox 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{ 
          var query = new ej.data.Query().select(['ContactName', 'CustomerID']);
          query = (e.text !== '') ? query.where('ContactName', 'startswith', e.text, true) : query;
          e.updateData(searchData, query);
        }
    }
});
//render the component
comboBoxObject.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</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/ej2-base/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="//cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <br>
        <input type="text" id="comboelement">
    </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 ComboBox 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 ComboBox.

Source
Preview
index.js
index.html
// 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 ComboBox component
    let comboObj: ComboBox = new ComboBox({
        //set the local data to dataSource property
        dataSource: data,
        // set the placeholder to ComboBox 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
    });
    comboObj.appendTo('#comboelement');
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 ComboBox</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/ej2-base/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css" rel="stylesheet">
    
    
<script src="//cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script>
</head>

<body>
    
    <div id="container" style="margin:50px auto 0; width:250px;">
        <br>
        <input type="text" id="comboelement">
    </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