PHP version of https://github.com/JedWatson/classnames

classNames.php

<?php

function classNames() {
	return join(' ',
		array_map(
			function ($arg) {
				if (is_array($arg)) {
					$values = [];
					foreach ($arg as $className => $show) {
						if ($show) {
							$values[] = $className;
						}
					}
					return join(' ', $values);
				} elseif (is_string($arg)) {
					return $arg;
				} else {
					throw new InvalidArgumentException("argument must be a string or object");
				}
			},
			func_get_args()
		)
	);
}

?>

<!-- Test case -->
<?
$show_spangle = true;
$show_blah = false;
?>

<!-- Old way -->
<div class="foo bar <?php if ($show_spangle): ?>spangle<? endif ?> <?php if ($show_blah): ?>blah<?php endif ?>"></div>

<!-- New way -->
<div class="<?= classNames('foo', 'bar', ['spangle' => $show_spangle, 'blah' => $show_blah]) ?>"></div>