functions.php

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


/**
 * Returns a string to be used for cache busting
 *
 * @return str
 */
function uri_tedx_cache_buster() {
	static $cache_buster;
	if ( empty( $cache_buster ) ) {
		$cache_buster = wp_get_theme()->get( 'Version' );
		// $cache_buster = date(time());
	}
	return $cache_buster;
}


/**
 * Returns the subdomain to use
 *
 * @return str
 */
function uri_tedx_get_the_subdomain() {

	$default = 'www';

	$whitelist = array(
		'www',
		'next',
		'quack',
	);

	$parsed_url = parse_url( get_site_url() );
	$host = explode( '.', $parsed_url['host'] );
	$subdomain = $host[0];

	return in_array( $subdomain, $whitelist ) ? $subdomain : $default;

}


/**
 * Echos the subdomain to use
 */
function uri_tedx_the_subdomain() {
	echo uri_tedx_get_the_subdomain();
}


if ( ! function_exists( 'uri_tedx_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 uri_tedx_setup() {
		/*
		 * Make theme available for translation.
		 * Translations can be filed in the /languages/ directory.
		 * If you're building a theme based on _s, use a find and replace
		 * to change 'uri' to the name of your theme in all the template files.
		 */
		load_theme_textdomain( 'uri', 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' );

		// add custom URI image sizes
		add_image_size( 'thumbnail@2x', 300, 300, true );
		add_image_size( 'third_column', 364 );
		add_image_size( 'half_column', 500 );
		add_image_size( 'full_column', 1000 );
		add_image_size( 'hero', 1280 );
		add_image_size( 'full_column@2x', 2000 );
		add_image_size( 'hero@2x', 2560 );

		// This theme uses wp_nav_menu() in one location.
		register_nav_menus(
			array(
				'menu-1' => esc_html__( 'Primary', 'uri' ),
			)
		);

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

		// Set up the WordPress core custom background feature.
		add_theme_support(
			'custom-background',
			apply_filters(
				'uri_tedx_custom_background_args',
				array(
					'default-color' => 'ffffff',
					'default-image' => '',
				)
			)
		);

		// Add theme support for selective refresh for widgets.
		add_theme_support( 'customize-selective-refresh-widgets' );

		// Add theme support for post formats
		add_theme_support(
			'post-formats',
			array(
				'video',
			)
		);

	}
endif;
add_action( 'after_setup_theme', 'uri_tedx_setup' );


/**
 * Label the custom image sizes.
 */
function uri_tedx_custom_sizes( $sizes ) {
	return array_merge(
		 $sizes,
		array(
			'thumbnail@2x' => __( 'Thumbnail @2x' ),
			'third_column' => __( 'Third Column' ),
			'half_column' => __( 'Half Column' ),
			'full_column' => __( 'Full Column' ),
			'hero' => __( 'Hero' ),
			'full_column@2x' => __( 'Full Column @2x' ),
			'hero@2x' => __( 'Hero @2x' ),
		)
		);
}
add_filter( 'image_size_names_choose', 'uri_tedx_custom_sizes' );


/**
 * Set max srcset image width to 2560px
 */
function set_max_srcset_image_width( $max_width ) {
	$max_width = 2560;
	return $max_width;
}
add_filter( 'max_srcset_image_width', 'set_max_srcset_image_width' );


/**
 * Enables the Excerpt meta box in Page edit screen.
 */
function uri_tedx_add_excerpt_support_for_pages() {
	add_post_type_support( 'page', 'excerpt' );
}
add_action( 'init', 'uri_tedx_add_excerpt_support_for_pages' );


/**
 * Add post-formats to post_type 'post'.
 */
function uri_tedx_add_post_formats_to_post() {
	add_post_type_support( 'post', 'post-formats' );
	register_taxonomy_for_object_type( 'post_format', 'post' );
}
add_action( 'init', 'uri_tedx_add_post_formats_to_post', 11 );


/**
 * Set the content width in pixels, based on the theme's design and stylesheet.
 *
 * Priority 0 to make it available to lower priority callbacks.
 *
 * @global int $content_width
 */
function uri_tedx_content_width() {
	$GLOBALS['content_width'] = apply_filters( 'uri_tedx_content_width', 1000 );
}
add_action( 'after_setup_theme', 'uri_tedx_content_width', 0 );


/**
 * Add open graph elements to the <head>
 *
 * @todo: allow other twitter handles
 */
function uri_tedx_open_graph() {
	global $post;
	$summary_type = 'summary';
	if ( is_single() || is_page() ) {
		$image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'full' );

		// use a larger image in twitter card if the image is wider than it is tall.
		if ( $image ) {
		$landscape = ( $image[1] > $image[2] );
		if ( true === $landscape ) {
				$summary_type = 'summary_large_image';
		}

		$image_thumb = $image[0];
		if ( empty( $image_thumb ) ) {
				$image_thumb  = get_template_directory_uri() . '/images/logo_uri_open_graph.jpg';
				$summary_type = 'summary_large_image';
		}
	}

		$title = get_the_title();
		if ( empty( $title ) ) {
			$title = get_bloginfo( 'name', 'display' ); }

		$excerpt = get_the_excerpt();

		if ( empty( $excerpt ) ) {
			if ( strpos( $post->post_content, '<!--more' ) !== false ) {
				$bits = explode( '<!--more', $post->post_content );
			} else {
				$bits = explode( "\n", wordwrap( $post->post_content, 200 ) );
			}
			$excerpt = $bits[0];
		}

		$excerpt = strip_tags( $excerpt );
		$excerpt = str_replace( '"', '&quot;', $excerpt );
		$excerpt = trim( $excerpt );

		?>
<meta name="description" content="<?php echo $excerpt; ?>" />
<meta name="twitter:card" content="<?php echo $summary_type; ?>" />
<meta name="twitter:site" content="@tedxuri" />
<meta name="twitter:creator" content="@tedxuri" />
<meta property="og:url" content="<?php echo get_permalink(); ?>" />
<meta property="og:title" content="<?php echo $title; ?>" />
<meta property="og:description" content="<?php echo $excerpt; ?>" />
<?php
if ( isset( $image_thumb ) ) :
				?>
<meta property="og:image" content="<?php echo $image_thumb; ?>" />
					<?php
endif;
	}
}

add_action( 'wp_head', 'uri_tedx_open_graph' );

/**
 * Enqueue scripts and styles.
 */
function uri_tedx_scripts() {
	wp_enqueue_style( 'uri-tedx-style', get_template_directory_uri() . '/style.css', array(), uri_tedx_cache_buster(), 'all' );

	wp_enqueue_script( 'uri-tedx-navigation', get_template_directory_uri() . '/js/navigation.js', array(), uri_tedx_cache_buster(), true );

	wp_enqueue_script( 'uri-tedx-smoothscroll', get_template_directory_uri() . '/js/smoothscroll.min.js', array(), uri_tedx_cache_buster(), true );

	wp_enqueue_script( 'uri-tedx-skip-link-focus-fix', get_template_directory_uri() . '/js/skip-link-focus-fix.js', array(), uri_tedx_cache_buster(), true );

	wp_enqueue_script( 'uri-tedx-scripts', get_template_directory_uri() . '/js/script.min.js', array(), uri_tedx_cache_buster(), true );

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


/**
 * Gets the current WP path as known by Apache, not WordPress.
 *
 * @param bool $strip is a switch to strip slashes from the end of the URL.
 * It does this so that paths like "who" and "who/*" can be differentiated.
 * Otherwise, there's no way to single out "who".
 *
 * @return str
 */
function uri_tedx_get_current_path( $strip = true ) {

	if ( strpos( $_SERVER['HTTP_REFERER'], 'wp-admin/customize.php' ) === false ) {
		$current_path = trim( $_SERVER['REQUEST_URI'] );
	} else {
		// when the Customizer is being used, we need to use the referrer
		// because the Request URI is a different endpoint.
		$url          = parse_url( $_SERVER['HTTP_REFERER'] );
		$q            = trim( urldecode( $url['query'] ) );
		$q            = str_replace( 'url=', '', $q );
		$url          = parse_url( $q );
		$current_path = $url['path'];
	}

	$base_bits = parse_url( site_url() );
	if ( strpos( $current_path, $base_bits['path'] ) === 0 ) {
		$current_path = substr( $current_path, strlen( $base_bits['path'] ) );
	}
	if ( true === $strip ) {
		$current_path = rtrim( $current_path, '/' );
	}

	return $current_path;
}


/**
 * Wrap oembeds with a styleable class
 *
 * @param str $html the html.
 * @param str $url is the URL that was originally included in the post.
 * @param arr $attr is an array with width and height... neither value seems to have a purpose.
 * @param str $post_id is the id of the current post.
 */
function uri_tedx_embed_oembed_html( $html, $url, $attr, $post_id ) {
	// parse the URL of the embed to convert the domain name into a CSS class.
	preg_match( '#(http|ftp)s?://(www\.)?([a-z0-9\.\-]+)/?.*#i', $url, $matches );
	$server_class = str_replace( '.', '-', $matches[3] );

	return '<div class="oembed oembed-' . $server_class . '" style="" data-url="' . $url . '">' . $html . '</div>';
}
add_filter( 'embed_oembed_html', 'uri_tedx_embed_oembed_html', 99, 4 );


/**
 * Get the featured image caption
 *
 * @param obj $post the post.
 */
function uri_tedx_get_thumbnail_caption( $post ) {
	if ( empty( $post ) ) {
		return false;
	}

	$thumbnail_id    = get_post_thumbnail_id( $post->ID );
	$thumbnail_image = get_posts(
		array(
			'p'         => $thumbnail_id,
			'post_type' => 'attachment',
		)
	);

	if ( $thumbnail_image && isset( $thumbnail_image[0] ) ) {
		return nl2br( $thumbnail_image[0]->post_excerpt );
	}
	return '';
}


/**
 * Remove WordPress page title prepends
 *
 * @param str $t the post title.
 */
function uri_tedx_sanitize_title( $t ) {

	$prepends = array(
		'Category: ',
		'Archive: ',
		'Tag: ',
	);

	foreach ( $prepends as $p ) {

		if ( substr( $t, 0, strlen( $p ) ) == $p ) {
			 return substr( $t, strlen( $p ) );
		}
	}

}


/**
 * Wrapper for Advanced Custom Fields get_field()
 */
function uri_tedx_get_field() {

	$r = false;

	if ( function_exists( 'get_field' ) ) {
		$r = call_user_func_array( 'get_field', func_get_args() );
	}

	return $r;

}


/**
 * Enable shortcodes in text widgets
 */
add_filter( 'widget_text', 'do_shortcode' );

/**
 * Talks custom post type
 */
require get_template_directory() . '/inc/talks-custom-fields.php';

/**
 * Implement the Custom Header feature.
 */
require get_template_directory() . '/inc/custom-header.php';

/**
 * Custom template tags for this theme.
 */
require get_template_directory() . '/inc/template-tags.php';

/**
 * Custom functions that act independently of the theme templates.
 */
require get_template_directory() . '/inc/extras.php';

/**
 * Customizer additions.
 */
require get_template_directory() . '/inc/customizer.php';

/**
 * Layout options
 */
require get_template_directory() . '/inc/layout-options.php';

/**
 * Load Jetpack compatibility file.
 */
require get_template_directory() . '/inc/jetpack.php';

/**
 * Add page slug to body class list in the format 'ln-{slug}'
 *
 * @param array $classes the classes.
 */
function uri_tedx_add_slug_body_class( $classes ) {
	global $post;
	if ( isset( $post ) ) {
		$classes[] = 'ln-' . $post->post_name;
	}
	return $classes;
}
add_filter( 'body_class', 'uri_tedx_add_slug_body_class' );

/**
 * Add a span around the title prefix so that the prefix can be hidden with CSS
 * if desired.
 * Note that this will only work with LTR languages.
 *
 * @see https://www.binarymoon.co.uk/2017/02/hide-archive-title-prefix-wordpress/
 *
 * @param string $title Archive title.
 * @return string Archive title with inserted span around prefix.
 */
function uri_tedx_hide_archive_title( $title ) {
	// Skip if the site isn't LTR, this is visual, not functional.
	// Should try to work out an elegant solution that works for both directions.
	if ( is_rtl() ) {
		return $title;
	}

	// Split the title into parts so we can wrap them with spans.
	$title_parts = explode( ': ', $title, 2 );

	// Given higher ed's propensity for colons in titles, let's be specific with our targeting
	$hide = array( 'Category', 'Tag', 'Archives' );

	// Glue it back together again.
	if ( ! empty( $title_parts[1] ) && in_array( trim( $title_parts[0] ), $hide ) ) {
		$title = wp_kses(
			$title_parts[1],
			array(
				'span' => array(
					'class' => array(),
				),
			)
		);
		$title = '<span class="screen-reader-text">' . esc_html( $title_parts[0] ) . ': </span>' . $title;
	}

	return $title;

}

add_filter( 'get_the_archive_title', 'uri_tedx_hide_archive_title' );

/**
 * Modify the query for the Talks archive page
 */
function uri_tedx_set_talks_per_page( $query ) {
	if ( ! is_admin() && $query->is_main_query() ) {
		// Not a query for an admin page.
		// It's the main query for a front end page of your site.

		if ( is_post_type_archive( 'talk' ) ) {
			$query->set( 'orderby', 'meta_value' );
			$query->set( 'meta_key', 'event' );
			$query->set( 'order', 'DEC' );
			$query->set( 'posts_per_page', 60 );
		}
	}
}
add_action( 'pre_get_posts', 'uri_tedx_set_talks_per_page' );