Before adding the select list itself, we would first add a line to initialize the select_list option in the ch3sapi_get_options function, if not found in the options retrieved from the database: $new_options['select_list'] = 'First';

The next step to rendering a drop-down list is to provide the list of all possible options, along with the option name, in the optional field data array. Here is an example of a call to the add_settings_field function call with such a list:

add_settings_field( 'select_list', 'Select List',
    'ch3sapi_select_list', 'ch3sapi_settings_section',
    'ch3sapi_main_section',
    array( 'name' => 'select_list',
           'choices' => array( 'First', 'Second', 'Third' ) ) );

With this information, we can provide an implementation for the ch3sapi_select_list function that will be able to render an HTML select element using the choices array to populate it:

function ch3sapi_select_list( $data = array() ) {
    extract ( $data );
    $options = ch3sapi_get_options();
    ?>
    <select name="ch3sapi_options[<?php echo $name; ?>]">
        <?php foreach( $choices as $item ) { ?>
        <option value="<?php echo $item; ?>"
        <?php selected( $options[$name] == $item ); ?>>
        <?php echo $item; ?></option>;
    <?php } ?>
    </select>
<?php }