functions.php

<?php
/**
 * Jeff How Starter functions and definitions
 * If you're building a theme based on Jeff How Starter, use a find and replace
 * to change 'jeffhowstarter' to the name of your theme in all the template files.
 *
 * @version 1.0
 */

/**
 * Sets up theme defaults and registers support for various WordPress features.
 */
function jeffhowstarter_setup() {
	/*
	 * Make theme available for translation.
	 */
	load_theme_textdomain( 'jeffhowstarter' );

	// 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' );

	add_image_size( 'jeffhowstarter-featured-image', 2000, 1200, true );

	add_image_size( 'jeffhowstarter-thumbnail-avatar', 100, 100, true );

	// Set the default content width.
	$GLOBALS['content_width'] = 525;

  /**
   * This theme assumes baked in navigation menus

	// This theme uses wp_nav_menu() in two locations.
	register_nav_menus( array(
		'top'    => __( 'Top Menu', 'jeffhowstarter' ),
		'social' => __( 'Social Links Menu', 'jeffhowstarter' ),
	) );
	
	*/

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

	/*
	 * Enable support for Post Formats.
	 *
	 * See: https://codex.wordpress.org/Post_Formats
	 */
	add_theme_support( 'post-formats', array(
		'aside',
		'image',
		'video',
		'quote',
		'link',
		'gallery',
		'audio',
	) );

	/**
	 * This theme assumes all header content baked in
	 *
	 
	// Add theme support for Custom Logo.
	add_theme_support( 'custom-logo', array(
		'width'       => 250,
		'height'      => 250,
		'flex-width'  => true,
	) );
	
	*/
	
	// Add theme support for selective refresh for widgets.
	add_theme_support( 'customize-selective-refresh-widgets' );

}
add_action( 'after_setup_theme', 'jeffhowstarter_setup' );

/**
 * Register custom fonts.
 */
function jeffhowstarter_fonts_url() {
	$fonts_url = '';
  
	$query_args = array(
		'family' => 'Open+Sans:400,400i,700,700i|Roboto+Slab:700'
	);

	$fonts_url = add_query_arg( $query_args, 'https://fonts.googleapis.com/css' );

	return esc_url_raw( $fonts_url );
}

/**
 * Add preconnect for Google Fonts.
 *
 * @param array  $urls           URLs to print for resource hints.
 * @param string $relation_type  The relation type the URLs are printed.
 * @return array $urls           URLs to print for resource hints.
 */
function jeffhowstarter_resource_hints( $urls, $relation_type ) {
	if ( wp_style_is( 'jeffhowstarter-fonts', 'queue' ) && 'preconnect' === $relation_type ) {
		$urls[] = array(
			'href' => 'https://fonts.gstatic.com',
			'crossorigin',
		);
	}

	return $urls;
}
add_filter( 'wp_resource_hints', 'jeffhowstarter_resource_hints', 10, 2 );

/**
 * Register widget area.
 *
 * @link https://developer.wordpress.org/themes/functionality/sidebars/#registering-a-sidebar
 */
function jeffhowstarter_widgets_init() {
	register_sidebar( array(
		'name'          => __( 'Blog Sidebar', 'jeffhowstarter' ),
		'id'            => 'sidebar-1',
		'description'   => __( 'Add widgets here to appear in your sidebar on blog posts and archive pages.', 'jeffhowstarter' ),
		'before_widget' => '<section id="%1$s" class="widget %2$s">',
		'after_widget'  => '</section>',
		'before_title'  => '<h2 class="widget-title">',
		'after_title'   => '</h2>',
	) );

	register_sidebar( array(
		'name'          => __( 'Footer 1', 'jeffhowstarter' ),
		'id'            => 'sidebar-2',
		'description'   => __( 'Add widgets here to appear in your footer.', 'jeffhowstarter' ),
		'before_widget' => '<section id="%1$s" class="widget %2$s">',
		'after_widget'  => '</section>',
		'before_title'  => '<h2 class="widget-title">',
		'after_title'   => '</h2>',
	) );

	register_sidebar( array(
		'name'          => __( 'Footer 2', 'jeffhowstarter' ),
		'id'            => 'sidebar-3',
		'description'   => __( 'Add widgets here to appear in your footer.', 'jeffhowstarter' ),
		'before_widget' => '<section id="%1$s" class="widget %2$s">',
		'after_widget'  => '</section>',
		'before_title'  => '<h2 class="widget-title">',
		'after_title'   => '</h2>',
	) );
}
add_action( 'widgets_init', 'jeffhowstarter_widgets_init' );

/**
 * Replaces "[...]" (appended to automatically generated excerpts) with ... and
 * a 'Continue reading' link.
 *
 * @since Twenty Seventeen 1.0
 *
 * @param string $link Link to single post/page.
 * @return string 'Continue reading' link prepended with an ellipsis.
 */
function jeffhowstarter_excerpt_more( $link ) {
	if ( is_admin() ) {
		return $link;
	}

	$link = sprintf( '<p class="link-more"><a href="%1$s" class="more-link">%2$s</a></p>',
		esc_url( get_permalink( get_the_ID() ) ),
		/* translators: %s: Name of current post */
		sprintf( __( 'Continue reading<span class="screen-reader-text"> "%s"</span>', 'jeffhowstarter' ), get_the_title( get_the_ID() ) )
	);
	return ' &hellip; ' . $link;
}
add_filter( 'excerpt_more', 'jeffhowstarter_excerpt_more' );

/**
 * Handles JavaScript detection.
 *
 * Adds a `js` class to the root `<html>` element when JavaScript is detected.
 *
 * @since Twenty Seventeen 1.0
 */
function jeffhowstarter_javascript_detection() {
	echo "<script>(function(html){html.className = html.className.replace(/\bno-js\b/,'js')})(document.documentElement);</script>\n";
}
add_action( 'wp_head', 'jeffhowstarter_javascript_detection', 0 );

/**
 * Add a pingback url auto-discovery header for singularly identifiable articles.
 */
function jeffhowstarter_pingback_header() {
	if ( is_singular() && pings_open() ) {
		printf( '<link rel="pingback" href="%s">' . "\n", get_bloginfo( 'pingback_url' ) );
	}
}
add_action( 'wp_head', 'jeffhowstarter_pingback_header' );


/**
 * Enqueue scripts and styles.
 */
function jeffhowstarter_scripts() {
	// Add custom fonts, used in the main stylesheet.
	wp_enqueue_style( 'jeffhowstarter-fonts', jeffhowstarter_fonts_url(), array(), null );

	// Theme stylesheet.
	wp_enqueue_style( 'jeffhowstarter-style', get_stylesheet_uri() );
	wp_enqueue_style('jeffhowstarter-stylesheet', get_theme_file_uri( '/assets/css/jeffhowstarter.css' ) );
	
  // Theme JavaScript
  wp_enqueue_script( 'jeffhowstarter-javascript', get_theme_file_uri( '/assets/js/jeffhowstarter.js' ), array( 'jquery-scrollto', 'font-face-observer' ), '1.0', true );
  wp_enqueue_script( 'font-face-observer', get_theme_file_uri( '/assets/js/fontfaceobserver.js' ), array( 'jquery' ), '2.0', true );

 
	// Load the html5 shiv.
	wp_enqueue_script( 'html5', get_theme_file_uri( '/assets/js/html5.js' ), array(), '3.7.3' );
	wp_script_add_data( 'html5', 'conditional', 'lt IE 9' );

	wp_enqueue_script( 'jeffhowstarter-skip-link-focus-fix', get_theme_file_uri( '/assets/js/skip-link-focus-fix.js' ), array(), '1.0', true );

	wp_enqueue_script( 'jquery-scrollto', get_theme_file_uri( '/assets/js/jquery.scrollTo.js' ), array( 'jquery' ), '2.1.2', true );

	wp_localize_script( 'jeffhowstarter-skip-link-focus-fix', 'jeffhowstarterScreenReaderText', $jeffhowstarter_l10n );

	if ( is_singular() && comments_open() && get_option( 'thread_comments' ) ) {
		wp_enqueue_script( 'comment-reply' );
	}
}
add_action( 'wp_enqueue_scripts', 'jeffhowstarter_scripts' );

/**
 * Add custom image sizes attribute to enhance responsive image functionality
 * for content images.
 *
 * @since Twenty Seventeen 1.0
 *
 * @param string $sizes A source size value for use in a 'sizes' attribute.
 * @param array  $size  Image size. Accepts an array of width and height
 *                      values in pixels (in that order).
 * @return string A source size value for use in a content image 'sizes' attribute.
 */
function jeffhowstarter_content_image_sizes_attr( $sizes, $size ) {
	$width = $size[0];

	if ( 740 <= $width ) {
		$sizes = '(max-width: 706px) 89vw, (max-width: 767px) 82vw, 740px';
	}

	if ( is_active_sidebar( 'sidebar-1' ) || is_archive() || is_search() || is_home() || is_page() ) {
		if ( ! ( is_page() && 'one-column' === get_theme_mod( 'page_options' ) ) && 767 <= $width ) {
			 $sizes = '(max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px';
		}
	}

	return $sizes;
}
add_filter( 'wp_calculate_image_sizes', 'jeffhowstarter_content_image_sizes_attr', 10, 2 );



/**
 * Add custom image sizes attribute to enhance responsive image functionality
 * for post thumbnails.
 *
 * @since Twenty Seventeen 1.0
 *
 * @param array $attr       Attributes for the image markup.
 * @param int   $attachment Image attachment ID.
 * @param array $size       Registered image size or flat array of height and width dimensions.
 * @return string A source size value for use in a post thumbnail 'sizes' attribute.
 */
function jeffhowstarter_post_thumbnail_sizes_attr( $attr, $attachment, $size ) {
	if ( is_archive() || is_search() || is_home() ) {
		$attr['sizes'] = '(max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px';
	} else {
		$attr['sizes'] = '100vw';
	}

	return $attr;
}
add_filter( 'wp_get_attachment_image_attributes', 'jeffhowstarter_post_thumbnail_sizes_attr', 10, 3 );

/**
 * Use front-page.php when Front page displays is set to a static page.
 *
 * @since Twenty Seventeen 1.0
 *
 * @param string $template front-page.php.
 *
 * @return string The template to be used: blank if is_home() is true (defaults to index.php), else $template.

function jeffhowstarter_front_page_template( $template ) {
	return is_home() ? '' : $template;
}
add_filter( 'frontpage_template',  'jeffhowstarter_front_page_template' );*/