How to create a custom control in customizer

Question

I'm trying to create a custom control which can select all contact form 7 forms in a plugin. I've done this

<?php 
   if( !class_exists( 'Silicon_CF7_Custom_Control' ) ) {
      class Silicon_CF7_Custom_Control extends WP_Customize_Control {
    /**
     * Returns true / false if the plugin: Contact Form 7 is activated;
     *
     * This right here disables the control for selecting a contact form IF the plugin isn\'t active
     *
     * @since Pixova Lite 1.15
     *
    * @return bool
     */

    public function active_callback( ) {

        if( class_exists( 'WPCF7' ) ) {
            return true;
        } else {
            return false;
        }
    }

    public function silicon_get_cf7_forms() {
        global $wpdb;

        // no more php warnings
        $contact_forms = array();

        // check if CF7 is activated
        if ( $this->active_callback()) {
            $cf7 = $wpdb->get_results("SELECT ID, post_title FROM $wpdb->posts WHERE post_type = 'wpcf7_contact_form' ");
            if ($cf7) {

                foreach ($cf7 as $cform) {
                    $contact_forms[$cform->ID] = $cform->post_title;
                }
            } else {
                $contact_forms[0] = __('No contact forms found', 'silicon');
            }
        }
        return $contact_forms;
    }

    public function render_content() {
        $Pixova_Lite_contact_forms = $this->silicon_get_cf7_forms();

        if ( !empty($Pixova_Lite_contact_forms ) ) { ?>
            <span class="customize-control-title"><?php echo esc_html($this->label); ?></span>
            <select <?php esc_url($this->link()); ?> style="width:100%;">
            <?php echo '<option value="default">'.__('Select your contact form', 'silicon').'</option>';
            foreach ($Pixova_Lite_contact_forms as $form_id => $form_title) {
                echo '<option value="' . sanitize_key( $form_id ). '" >' . esc_html( $form_title ). '</option>';
            }
            echo '</select>';
        }
    }
}

}

And required it here

require_once ( dirname( __FILE__ ) . '/controls/contact-form.php' );

But if I call it like this

$wp_customize->add_control( new Silicon_CF7_Custom_Control(
$wp_customize,
$setting_id,
    array(
        'label'             => $label,
        'section'           => $section_id,
        'priority'          => $priority,
        'type'              => 'silicon_contact_form_7'
    ) ) );

I get an error that says

Fatal error: Class 'Silicon_CF7_Custom_Control' not found in C:\wamp\www\wp-5\wp-content\plugins\silicon-extension\inc\customize\sections\contact.php on line 41

Answer 1

I've solved the issue, it was because I called the class before creating it

require_once ( dirname( __FILE__ ) . '/sections/contact.php' );
require_once ( dirname( __FILE__ ) . '/controls/contact-form.php' );