/lib/utils.php

<?php
// Add post thumbnails (http://codex.wordpress.org/Post_Thumbnails)
add_theme_support('post-thumbnails');
// set_post_thumbnail_size(150, 150, false);
// add_image_size('category-thumb', 300, 9999); // 300px wide (and unlimited height)

// Add post formats (http://codex.wordpress.org/Post_Formats)
// add_theme_support('post-formats', array('aside', 'gallery', 'link', 'image', 'quote', 'status', 'video', 'audio', 'chat'));



// Backwards compatibility for older than PHP 5.3.0
if (!defined('__DIR__')) { define('__DIR__', dirname(__FILE__)); }

// Define helper constants
$get_theme_name = explode('/themes/', get_template_directory());

define('WP_BASE',                   wp_base_dir());
define('THEME_NAME',                next($get_theme_name));
define('RELATIVE_PLUGIN_PATH',      str_replace(site_url() . '/', '', plugins_url()));
define('FULL_RELATIVE_PLUGIN_PATH', WP_BASE . '/' . RELATIVE_PLUGIN_PATH);
define('RELATIVE_CONTENT_PATH',     str_replace(site_url() . '/', '', content_url()));
define('THEME_PATH',                RELATIVE_CONTENT_PATH . '/themes/' . THEME_NAME);

// show home in menus
function home_page_menu_args( $args ) {
$args['show_home'] = true;
return $args;
}
add_filter( 'wp_page_menu_args', 'home_page_menu_args' );

/**
 * Page titles
 */
function title() {
	if (is_home()) {
		if (get_option('page_for_posts', true)) {
			echo get_the_title(get_option('page_for_posts', true));
		} else {
			_e('Latest Posts', 'roots');
		}
	} elseif (is_archive()) {
		$term = get_term_by('slug', get_query_var('term'), get_query_var('taxonomy'));
		if ($term) {
			echo $term->name;
		} elseif (is_post_type_archive()) {
			echo get_queried_object()->labels->name;
		} elseif (is_day()) {
			printf(__('Daily Archives: %s', 'roots'), get_the_date());
		} elseif (is_month()) {
			printf(__('Monthly Archives: %s', 'roots'), get_the_date('F Y'));
		} elseif (is_year()) {
			printf(__('Yearly Archives: %s', 'roots'), get_the_date('Y'));
		} elseif (is_author()) {
			global $post;
			$author_id = $post->post_author;
			printf(__('Author Archives: %s', 'roots'), get_the_author_meta('display_name', $author_id));
		} else {
			single_cat_title();
		}
	} elseif (is_search()) {
		printf(__('Search Results for %s', 'roots'), get_search_query());
	} elseif (is_404()) {
		_e('File Not Found', 'roots');
	} else {
		the_title();
	}
}

/**
 * Show an admin notice if .htaccess isn't writable
 */
function htaccess_writable() {
	if (!is_writable(get_home_path() . '.htaccess')) {
		if (current_user_can('administrator')) {
			add_action('admin_notices', create_function('', "echo '<div class=\"error\"><p>" . sprintf(__('Please make sure your <a href="%s">.htaccess</a> file is writable ', 'roots'), admin_url('options-permalink.php')) . "</p></div>';"));
		}
	}
}

add_action('admin_init', 'htaccess_writable');

// returns WordPress subdirectory if applicable
function wp_base_dir() {
	preg_match('!(https?://[^/|"]+)([^"]+)?!', site_url(), $matches);
	if (count($matches) === 3) {
		return end($matches);
	} else {
		return '';
	}
}

// opposite of built in WP functions for trailing slashes
function leadingslashit($string) {
	return '/' . unleadingslashit($string);
}

function unleadingslashit($string) {
	return ltrim($string, '/');
}

function add_filters($tags, $function) {
	foreach($tags as $tag) {
		add_filter($tag, $function);
	}
}

function is_element_empty($element) {
	$element = trim($element);
	return empty($element) ? false : true;
}