WP: Visual composer custom element

vc-custom-element.php

<?php

// Before VC Init
add_action( 'vc_before_init', 'vc_before_init_actions' );
 
function vc_before_init_actions() {
     
    //.. Code from other Tutorials ..//
 
    // Require new custom Element
    require_once( get_stylesheet_directory().'/vc-custom-element.php' ); 
     
}

/*
Element Description: vcCustomElement
*/
 
// Element Class 
class vcCustomElement extends WPBakeryShortCode {
     
    // Element Init
    function __construct() {
        add_action( 'init', array( $this, 'vc_custom_mapping' ) );
        add_shortcode( 'vc_nvl_cat_item', array( $this, 'vc_custom_html' ) );
    }
     
    // Element Mapping
    public function vc_custom_mapping() {
         
        // Stop all if VC is not enabled
        if ( !defined( 'WPB_VC_VERSION' ) ) {
            return;
        }
         
        // Map the block with vc_map()
        vc_map( 
            array(
                'name' => __('Custom element item', 'text-domain'),
                'base' => 'custom_element_item_base',
                'description' => __('Custom element item', 'text-domain'), 
                'category' => __('Custom element', 'text-domain'),   
                'icon' => get_template_directory_uri().'/assets/img/vc-icon.png',            
                'params' => array(   
                         
                    array(
                        'type' => 'textfield',
                        'holder' => 'div',
                        'class' => 'field-class',
                        'heading' => __( 'Field name', 'text-domain' ),
                        'param_name' => 'param',
                        'value' => __( 'Field name', 'text-domain' ),
                        'description' => __( 'Field name', 'text-domain' ),
                        'admin_label' => false,
                        'weight' => 0,
                        'group' => 'Field group',
                    ),
  

                ),
            )
        );                                
        
    }
     
     
    // Element HTML
    public function vc_custom_html( $atts ) {
         
        // Params extraction
        extract(
            shortcode_atts(
                array(
                    'param'   => '',
                ), 
                $atts
            )
        );
				
				ob_start();
        ?>
				
				<div><?php echo $param; ?></div>
        
				<?php
        return ob_get_clean();
         
    }
     
} // End Element Class
 
 
// Element Class Init
new vcCustomElement();