functions.php

<?php
/**
 * wtsp functions and definitions
 *
 * @link https://developer.wordpress.org/themes/basics/theme-functions/
 *
 * @package wtsp
 */

function register_my_session(){
 	if( !session_id() ) {
 		session_start();
 	}
}
add_action('init', 'register_my_session');

if ( ! function_exists( 'wtsp_setup' ) ) :
	/**
	 * Sets up theme defaults and registers support for various WordPress features.
	 *
	 * Note that this function is hooked into the after_setup_theme hook, which
	 * runs before the init hook. The init hook is too late for some features, such
	 * as indicating support for post thumbnails.
	 */
	function wtsp_setup() {
		/*
		 * Make theme available for translation.
		 * Translations can be filed in the /languages/ directory.
		 * If you're building a theme based on wtsp, use a find and replace
		 * to change 'wtsp' to the name of your theme in all the template files.
		 */
		load_theme_textdomain( 'wtsp', get_template_directory() . '/languages' );

		// Add default posts and comments RSS feed links to head.
		add_theme_support( 'automatic-feed-links' );

		/*
		 * Let WordPress manage the document title.
		 * By adding theme support, we declare that this theme does not use a
		 * hard-coded <title> tag in the document head, and expect WordPress to
		 * provide it for us.
		 */
		add_theme_support( 'title-tag' );

		/*
		 * Enable support for Post Thumbnails on posts and pages.
		 *
		 * @link https://developer.wordpress.org/themes/functionality/featured-images-post-thumbnails/
		 */
		add_theme_support( 'post-thumbnails' );

		/*
		 * Switch default core markup for search form, comment form, and comments
		 * to output valid HTML5.
		 */
		add_theme_support( 'html5',[
			'search-form',
			'comment-form',
			'comment-list',
			'gallery',
			'caption',
		]);
	}

endif;
add_action( 'after_setup_theme', 'wtsp_setup' );

// Function to change email address
function wpb_sender_email( $original_email_address ) {
	return 'no-reply@wordpress.test';
}
add_filter( 'wp_mail_from', 'wpb_sender_email' );

// Function to change sender name
function wpb_sender_name( $original_email_from ) {
	return get_bloginfo('name'); //ex. 'Wordpress Test';
}
add_filter( 'wp_mail_from_name', 'wpb_sender_name' );

/* Add the default style and some other */
add_action( 'wp_enqueue_scripts', 'wtsp_my_styles_method');
function wtsp_my_styles_method() {

	wp_enqueue_style(
		'style',
		get_stylesheet_uri()
	);

	wp_enqueue_style(
		'fontawesome',
    'https://use.fontawesome.com/releases/v5.12.0/css/all.css',
		[ ],
		'5.12.0'
	);

	wp_enqueue_style(
		'icons',
		get_template_directory_uri() . '/dist/icons/icons.css',
		['style'],
		'20200126'
	);

	wp_enqueue_style(
		'slick-carousel',
		'https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.css',
		[ ],
		'1.9.0'
	);

	wp_enqueue_style(
		'slick-carousel-theme',
		'https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick-theme.css',
		['slick-carousel'],
		'1.9.0'
	);

  wp_enqueue_style(
    'animate-css',
    'https://cdnjs.cloudflare.com/ajax/libs/animate.css/4.0.0/animate.min.css',
    [],
    '4.0.0'
  );

	wp_enqueue_style(
		'main',
		get_template_directory_uri() . '/dist/styles/main.css',
		['style', 'fontawesome', 'icons'],
		'20200126'
	);

}

/* Add some js scripts */
add_action( 'wp_enqueue_scripts', 'wtsp_my_scripts_method');
function wtsp_my_scripts_method() {

	wp_enqueue_script( 'jquery' );
	wp_enqueue_script( 'lodash' );

	wp_enqueue_script(
		'popper.js',
		'https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js',
		[ ],
		'1.14.7',
		true
	);

	wp_enqueue_script(
		'bootstrap',
		'https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js',
		['jquery', 'popper.js'],
		'4.3.1',
		true
	);

	wp_enqueue_script(
		'slick',
		'https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.min.js',
		['jquery'],
		'1.9.0',
		true
	);

	wp_enqueue_script(
		'main',
		get_template_directory_uri() . '/dist/scripts/main.js',
		['jquery', 'bootstrap', 'slick'],
		'20200126',
		true
	);

}

/* Enamble custom thumbnail sizes */
if ( function_exists( 'add_image_size' ) ) {
    add_image_size( '1920', 1920 );
	add_image_size( '800x600', 800, 600, true );
}

/* Customize the excerpt lenght */
add_filter( 'excerpt_more', 'wtsp_new_excerpt_more' );
function wtsp_new_excerpt_more( $more ) {
	return '…';
}

/* Enable custom menu */
add_action( 'init', 'wtsp_register_my_menu' );
function wtsp_register_my_menu( ) {
	register_nav_menu( 'mainmenu', 'Main menu of the theme');
	register_nav_menu( 'footermenu', 'Footer menu of the theme');
}

function wtsp_content_width() {
	$GLOBALS['content_width'] = apply_filters( 'wtsp_content_width', 1200 );
}
add_action( 'after_setup_theme', 'wtsp_content_width', 0 );

/* Title Tag */
if ( ! function_exists( '_wp_render_title_tag' ) ) {
	function wtsp_render_title() { ?>
		<title><?php wp_title( '-', true, 'right' ); ?></title>
	<?php }
	add_action( 'wp_head', 'wtsp_render_title' );
}