Wordpress Custom Taxonomy Additional Fields Used with any number of Taxonomies High Usability

custom_taxonomy_additional_fields.php

<?php

/**
 * Base class
 **/
if ( ! class_exists( 'CustomTaxonomyAdditionalFields' ) ) {

	abstract class CustomTaxonomyAdditionalFields {

		protected $taxonomy_slug;

		public function __construct( $taxonomy_slug )
		{
			$this->taxonomy_slug = $taxonomy_slug ;

			$this->init();
		}

		/*
		 * Initialize the class and start calling our hooks and filters
		 * @since 1.0.0
		*/
		public function init() {
			add_action( "{$this->taxonomy_slug}_add_form_fields", array ( $this, 'add_additional_fields' ), 10, 2 );
			add_action( "created_{$this->taxonomy_slug}", array ( $this, 'save_additional_fields' ), 10, 2 );
			add_action( "{$this->taxonomy_slug}_edit_form_fields", array ( $this, 'update_taxonomy_add_additional_fields' ), 10, 2 );
			add_action( "edited_{$this->taxonomy_slug}", array ( $this, 'update_taxonomy_save_additional_fields' ), 10, 2 );

			add_action( 'admin_enqueue_scripts', array( $this, 'load_media' ) );
			add_action( 'admin_footer', array ( $this, 'add_script' ) );
		}

		public function load_media() {
			wp_enqueue_media();
		}

		/*
		 * Add a form field in the new category page
		 * @since 1.0.0
		*/
		public function add_additional_fields ( $taxonomy ) {
			do_action( "create_{$this->taxonomy_slug}_term_add_additional_form_fields" , $taxonomy );
		}

		/*
		 * Save the form field
		 * @since 1.0.0
		*/
		public function save_additional_fields ( $term_id, $t_id ) {
			do_action( "create_{$this->taxonomy_slug}_term_save_additional_form_fields" , $term_id, $t_id );
		}

		/*
		 * Edit the form field
		 * @since 1.0.0
		*/
		public function update_taxonomy_add_additional_fields ( $term, $taxonomy ) {
			do_action( "update_{$this->taxonomy_slug}_term_add_additional_form_fields" , $term, $taxonomy );
		}

		/*
		 * Update the form field value
		 * @since 1.0.0
		 */
		public function update_taxonomy_save_additional_fields ( $term_id, $t_id ) {
			do_action( "update_{$this->taxonomy_slug}_term_save_additional_form_fields" , $term_id, $t_id );
		}

		/*
		 * Add script
		 * @since 1.0.0
		 */
		public function add_script() {
			do_action( "create_or_update_{$this->taxonomy_slug}_custom_scripts" );
		}
	}
}

/**
 * Class to Use the base Class added actions
 *
 * Class anyTaxonomyAdditionalFields
 */
class anyTaxonomyAdditionalFields extends CustomTaxonomyAdditionalFields{

	protected $taxonomy_slug = "custom_tax_name" ;

	function __construct()
	{
		parent::__construct( $this->taxonomy_slug );

		$this->add_actions();
	}

	public function add_actions()
	{
		add_action("{$this->taxonomy_slug}_add_form_fields", array( $this, "add_form_fields" ) );
		add_action("created_{$this->taxonomy_slug}", array( $this, "save_added_fields" ) );
		add_action("{$this->taxonomy_slug}_edit_form_fields", array( $this, "update_form_fields" ) );
		add_action("edited_{$this->taxonomy_slug}", array( $this, "save_updated_form_fields" ) );

		add_action("create_or_update_{$this->taxonomy_slug}_custom_scripts" , array( $this, "add_footer_script" ) );
	}

	public function add_form_fields( $taxonomy )
	{
		// put html here
	}

	public function save_added_fields( $term_id, $t_id )
	{
		// save from $_POST Request
	}

	public function update_form_fields( $term )
	{
		// put html here
	}

	public function save_updated_form_fields( $term_id, $t_id )
	{
		// save from $_POST Request
	}

	public function add_footer_script()
	{
		// js code if you want
	}
}


new anyTaxonomyAdditionalFields();