Wordpress 4.1 TinyMce Button Plugin

I'm trying to add a button on tinymce editor in wordpress

WordPress version: 4.1

I followed this tutorial : http://code.tutsplus.com/tutorials/guide-to-creating-your-own-wordpress-editor-buttons--wp-30182

But it doesn't work. I've at least googled the assignment and I've tried to find something but no results.

Anyone know what's wrong with the tutorial?

All I want to do is add a button on tinymce that takes the youtube url and add a custom html with a link where the cursor is.

Thank you in advance, I'm really new to php, wordpress and tinymce.

edit:

Try the tutorial link suggested by @Kaloyan Ivanov : https://www.gavick.com/blog/wordpress-tinymce-custom-buttons

My steps:

1. I added the first 4 php codes at the end of the theme's functions.php

        //add custom plugin to tinymce
        add_action('admin_head', 'gavickpro_add_my_tc_button');

        function gavickpro_add_my_tc_button() {
            global $typenow;
            // check user permissions
            if ( !current_user_can('edit_posts') && !current_user_can('edit_pages') ) {
            return;
            }
            // verify the post type
            if( ! in_array( $typenow, array( 'post', 'page' ) ) )
                return;
            // check if WYSIWYG is enabled
            if ( get_user_option('rich_editing') == 'true') {
                add_filter("mce_external_plugins", "gavickpro_add_tinymce_plugin");
                add_filter('mce_buttons', 'gavickpro_register_my_tc_button');
            }
        }

        function gavickpro_add_tinymce_plugin($plugin_array) {
            $plugin_array['gavickpro_tc_button'] = plugins_url( '/text-button.js', __FILE__ ); // CHANGE THE BUTTON SCRIPT HERE
            return $plugin_array;
        }

        function gavickpro_register_my_tc_button($buttons) {
           array_push($buttons, "gavickpro_tc_button");
           return $buttons;
        }

2. Then I created a file called text-button.js in the same theme folder as functions.php and added the code

            (function() {
                tinymce.PluginManager.add('gavickpro_tc_button',   function( editor, url ) {
                    editor.addButton( 'gavickpro_tc_button', {
                        text: 'My test button',
                        icon: false,
                        onclick: function() {
                            editor.insertContent('Hello World!');
                        }
                    });
                });
            })();

but this doesn't work, it makes all tinymce buttons in the editor disappear

Ultimately, just a little change (as suggested by Kaloyan Ivanov):

Change the line:

$plugin_array['gavickpro_tc_button'] = plugins_url( '/text-button.js', __FILE__ );

and:

$plugin_array['gavickpro_tc_button'] = get_bloginfo( 'stylesheet_directory' ) . '/text-button.js';

Thanks to Kaloyan Ivanov and gavick.com/blog, it's new tinymce editor for wordpress 4.1