Templates in Combo Box Control

19 Feb 20247 minutes to read

The ComboBox has been provided with several options to customize each list item, group title, selected value, header, and footer elements. It uses the Essential JS 2 Template engine to compile and render the elements properly.

Item template

The content of each list item within the ComboBox can be customized with the help of itemTemplate property.

In the following sample, each list item is split into two columns to display relevant data.

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="customers" query="new ej.data.Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6)" placeholder="Select a customer" popupHeight="200px"
                          itemTemplate="@Html.Raw("<span><span class='name'>${FirstName}</span><span class ='city'>${City}</span></span>")">
            <e-combobox-fields value="FirstName"></e-combobox-fields>
            <e-data-manager url="https://services.odata.org/V4/Northwind/Northwind.svc/" adaptor="ODataV4Adaptor" crossDomain="true"></e-data-manager>
        </ejs-combobox>
    </div>
</div>

<style>
    .city {
        right: 15px;
        position: absolute;
    }
</style>

Group template

The group header title under which appropriate sub-items are categorized can also be customized with the help of groupTemplate property. This template is common for both inline and floating group header template.

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="customers" query="new ej.data.Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6).where(new ej.data.Predicate('City', 'equal','london').or('City','equal','seattle'))" placeholder="Select a customer" popupHeight="200px"
                          groupTemplate="@Html.Raw("<strong>${City}</strong>")">
            <e-combobox-fields groupBy="City" value="FirstName"></e-combobox-fields>
            <e-data-manager url="https://services.odata.org/V4/Northwind/Northwind.svc/" adaptor="ODataV4Adaptor" crossDomain="true"></e-data-manager>
        </ejs-combobox>
    </div>
</div>

Header template

The header element is shown statically at the top of the popup list items within the ComboBox, and any custom element can be placed as a header element using the headerTemplate property.

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="customers" query="new ej.data.Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6)" placeholder="Find an Employee" popupHeight="200px"
                          headerTemplate="@Html.Raw("<span class='head'><span class='name'>Name</span><span class='city'>City</span></span>")"
                          itemTemplate="@Html.Raw("<span class='item' ><span class='name'>${FirstName}</span><span class='city'>${City}</span></span>")">
            <e-combobox-fields value="FirstName"></e-combobox-fields>
            <e-data-manager url="https://services.odata.org/V4/Northwind/Northwind.svc/" adaptor="ODataV4Adaptor" crossDomain="true"></e-data-manager>
        </ejs-combobox>
    </div>
</div>

<style>
    .head, .item {
        display: table;
        width: 100%;
        margin: auto;
    }

    .head {
        height: 40px;
        font-size: 15px;
        font-weight: 600;
    }

    .name, .city {
        display: table-cell;
        vertical-align: middle;
        width: 50%;
    }

    .head .name {
        text-indent: 16px;
    }

    .head .city {
        text-indent: 10px;
    }
</style>

The ComboBox has options to show a footer element at the bottom of the list items in the popup list. Here, you can place any custom element as a footer element using the footerTemplate property.

@{
    var data = new string[] { "Badminton", "Basketball", "Cricket", "Football", "Golf", "Gymnastics", "Hockey", "Tennis" };
}

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="employees" dataSource="@data" placeholder="Select a game" popupHeight="270px"
                          footerTemplate="@Html.Raw( "<span class='foot'> Total list items: " + 8 + "</span>")">
            <e-combobox-fields value="Name"></e-combobox-fields>
        </ejs-combobox>
    </div>
</div>

<style>
    .foot {
        text-indent: 1.2em;
        display: block;
        font-size: 15px;
        line-height: 40px;
        border-top: 1px solid #e0e0e0;
    }
</style>

No records template

The ComboBox is provided with support to custom design the popup list content when no data is found and no matches are found on search with the help of noRecordsTemplate property.

@{
    var data = new string[] { };
}

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="employees" dataSource="@data" placeholder="Select an employee" popupHeight="270px"
                          noRecordsTemplate="@Html.Raw("<span class='norecord'> NO DATA AVAILABLE</span>")">
            <e-combobox-fields value="Name"></e-combobox-fields>
        </ejs-combobox>
    </div>
</div>

Action failure template

There is also an option to custom design the popup list content when the data fetch request fails at the remote server. This can be achieved using the actionFailureTemplate property.

<div class='control-wrapper'>
    <div style='padding-top:75px;'>
        <ejs-combobox id="customers" query="new ej.data.Query().from('Employees').select(['FirstName']).take(6)" placeholder="Select a customer" popupHeight="200px"
                          actionFailureTemplate="@Html.Raw("<span class='action-failure'> Data fetch get fails</span>")">
            <e-combobox-fields value="FirstName"></e-combobox-fields>
            <e-data-manager url="https://services.odata.org/V4/Northwind/Northwind.svcs/" adaptor="ODataV4Adaptor" crossDomain="true"></e-data-manager>
        </ejs-combobox>
    </div>
</div>

NOTE

View Sample in GitHub.

See also