storefront/inc/functions/extras.php

<?php
/**
 * Custom functions that act independently of the theme templates
 *
 * Eventually, some of the functionality here could be replaced by core features
 *
 * @package storefront
 */

/**
 * Get our wp_nav_menu() fallback, wp_page_menu(), to show a home link.
 *
 * @param array $args Configuration arguments.
 * @return array
 */
function storefront_page_menu_args( $args ) {
	$args['show_home'] = true;
	return $args;
}

/**
 * Adds custom classes to the array of body classes.
 *
 * @param array $classes Classes for the body element.
 * @return array
 */
function storefront_body_classes( $classes ) {
	// Adds a class of group-blog to blogs with more than 1 published author.
	if ( is_multi_author() ) {
		$classes[] = 'group-blog';
	}

	return $classes;
}

/**
 * Filters wp_title to print a neat <title> tag based on what is being viewed.
 *
 * @param string $title Default title text for current view.
 * @param string $sep Optional separator.
 * @return string The filtered title.
 */
function storefront_wp_title( $title, $sep ) {
	if ( is_feed() ) {
		return $title;
	}

	global $page, $paged;

	// Add the blog name
	$title .= get_bloginfo( 'name', 'display' );

	// Add the blog description for the home/front page.
	$site_description = get_bloginfo( 'description', 'display' );
	if ( $site_description && ( is_home() || is_front_page() ) ) {
		$title .= " $sep $site_description";
	}

	// Add a page number if necessary:
	if ( ( $paged >= 2 || $page >= 2 ) && ! is_404() ) {
		$title .= " $sep " . sprintf( __( 'Page %s', 'storefront' ), max( $paged, $page ) );
	}

	return $title;
}

/**
 * Sets the authordata global when viewing an author archive.
 *
 * This provides backwards compatibility with
 * http://core.trac.wordpress.org/changeset/25574
 *
 * It removes the need to call the_post() and rewind_posts() in an author
 * template to print information about the author.
 *
 * @global WP_Query $wp_query WordPress Query object.
 * @return void
 */
function storefront_setup_author() {
	global $wp_query;

	if ( $wp_query->is_author() && isset( $wp_query->post ) ) {
		$GLOBALS['authordata'] = get_userdata( $wp_query->post->post_author );
	}
}

/**
 * Query WooCommerce activation
 */
if ( ! function_exists( 'is_woocommerce_activated' ) ) {
	function is_woocommerce_activated() {
		if ( class_exists( 'woocommerce' ) ) { return true; } else { return false; }
	}
}

/**
 * Schema type
 * @return string schema itemprop type
 */
function storefront_html_tag_schema() {
    $schema = 'http://schema.org/';
    $type 	= 'WebPage';

    // Is single post
    if ( is_singular( 'post' ) ) {
        $type = "Article";
    }

    // Is author page
    elseif ( is_author() ) {
        $type = 'ProfilePage';
    }

    // Is search results page
    elseif ( is_search() ) {
        $type = 'SearchResultsPage';
    }

    echo 'itemscope="itemscope" itemtype="' . $schema . $type . '"';
}

/**
 * Returns true if a blog has more than 1 category.
 *
 * @return bool
 */
function storefront_categorized_blog() {
	if ( false === ( $all_the_cool_cats = get_transient( 'storefront_categories' ) ) ) {
		// Create an array of all the categories that are attached to posts.
		$all_the_cool_cats = get_categories( array(
			'fields'     => 'ids',
			'hide_empty' => 1,

			// We only need to know if there is more than one category.
			'number'     => 2,
		) );

		// Count the number of categories that are attached to the posts.
		$all_the_cool_cats = count( $all_the_cool_cats );

		set_transient( 'storefront_categories', $all_the_cool_cats );
	}

	if ( $all_the_cool_cats > 1 ) {
		// This blog has more than 1 category so storefront_categorized_blog should return true.
		return true;
	} else {
		// This blog has only 1 category so storefront_categorized_blog should return false.
		return false;
	}
}

/**
 * Flush out the transients used in storefront_categorized_blog.
 */
function storefront_category_transient_flusher() {
	// Like, beat it. Dig?
	delete_transient( 'storefront_categories' );
}
add_action( 'edit_category', 'storefront_category_transient_flusher' );
add_action( 'save_post',     'storefront_category_transient_flusher' );