A generic functions file for WP theme, When creating custom Post Types

functions.php

<?php
/*
Shout Out to :
	http://stackoverflow.com/questions/27896131
	http://webexplorar.com/wordpress-create-custom-post-types-with-tags-and-categories
*/
add_action ('init', 'register_custom_post_type_event');

function register_custom_post_type_event() {
	$labels = array(
		'name' => _x('Event', 'post type general name'),
		'singular_name' => _x('Event', 'post type singular name'),
		'add_new' => _x('Add Event', 'event'),
		'add_new_item' => __('Add New Event'),
		'edit_item' => __('Edit Event'),
		'new_item' => __('New Event'),
		'all_items' => __('All Events'),
		'view_item' => __('View Event'),
		'search_items' => __('Search Events'),
		'not_found' => __('No Events found'),
		'not_found_in_trash' => __('No Events found in Trash'),
		'parent_item_colon' => '',
		'menu_name' => __('Event')
	);

	$args = array(
		'labels' => $labels,
		'public' => true,
		'publicly_queryable' => true,
		'show_ui' => true,
		'show_in_menu' => true,
		'query_var' => true,
		'rewrite' => array('slug' => 'event'),
		'capability_type' => 'post',
		'has_archive' => true,
		'hierarchical' => true,
		'menu_position' => null,
		'supports' => array('title', 'editor', 'excerpt', 'thumbnail', 'author')
	);
	register_post_type('event', $args);

	register_taxonomy( 'event_categories', array('event'), array(
        'hierarchical' => true, 
        'label' => 'Event Categories', 
        'singular_label' => 'Event Category', 
        'rewrite' => array( 'slug' => 'categories', 'with_front'=> false )
        )
    );

    register_taxonomy_for_object_type( 'event_categories', 'event' );
}

add_action( 'init', 'event_tag_taxonomies' ); //change order add_action( 'init', 'news_tag_taxonomies', 0 );
 
function event_tag_taxonomies() {
 
	// Add new taxonomy, NOT hierarchical (like tags)
	$labels = array(
		'name' => _x( 'Event Tags', 'taxonomy general name' ),
		'singular_name' => _x( 'Tag', 'taxonomy singular name' ),
		'search_items' => __( 'Search Tags' ),
		'popular_items' => __( 'Popular Tags' ),
		'all_items' => __( 'All Tags' ),
		'parent_item' => null,
		'parent_item_colon' => null,
		'edit_item' => __( 'Edit Tag' ),
		'update_item' => __( 'Update Tag' ),
		'add_new_item' => __( 'Add New Tag' ),
		'new_item_name' => __( 'New Tag Name' ),
		'separate_items_with_commas' => __( 'Separate tags with commas' ),
		'add_or_remove_items' => __( 'Add or remove tags' ),
		'choose_from_most_used' => __( 'Choose from the most used tags' ),
		'menu_name' => __( 'Event Tags' ),
	);
 
	register_taxonomy('event_tag','event',array(
		'hierarchical' => false,
		'labels' => $labels,
		'show_ui' => true,
		'update_count_callback' => '_update_post_term_count',
		'query_var' => true,
		'rewrite' => array( 'slug' => 'tag' ),
	));
}