A simple way to manage a slideshow with WordPress

functions.php

<?php
add_theme_support('post-thumbnails');
add_image_size('slideshow-mini', 870, 500, true);

print-slideshow.php

<?php
$images = get_attachments_by_media_tags('media_tags=slideshow');
echo slideshow($images);

result.html

<div id="carousel-4fbea6cb57c5b" class="carousel slide">

	<div class="carousel-inner">
		<div class="item active">

			<img width="870" height="500"
				src="http://www.emanueletessore.com/wp-content/uploads/2012/05/bootstrap-mdo-sfmoma-03.jpg"
				class="attachment-slideshow-mini"
				alt="Third Thumbnail alternate text" title="Third Thumbnail label" />

			<div class="carousel-caption">

				<h4>Third Thumbnail label</h4>

				<p>Cras justo odio, dapibus ac facilisis in, egestas eget quam.
					Donec id elit non mi porta gravida at eget metus. Nullam id dolor
					id nibh ultricies vehicula ut id elit.</p>

			</div>

		</div>
		<div class="item">

			<!-- second item here -->

		</div>
		<div class="item">

			<!-- third item here -->

		</div>
	</div>

	<a class="carousel-control left" href="#carousel-4fbea6cb57c5b"
		data-slide="prev">&lsaquo;</a> <a class="carousel-control right"
		href="#carousel-4fbea6cb57c5b" data-slide="next">&rsaquo;</a>

</div>

slideshow.php

<?php
function slideshow($images=null){

	if(isset($images)){
		$images = (array)get_children( 'post_type=attachment&post_mime_type=image&post_parent='.get_the_ID() );
	}
	$uid = uniqid('carousel-');
	$tpl = <<< EOF
		<div class="item%active%">
			%img%
			<div class="carousel-caption">
				<h4>%title%</h4>
				%description%
			</div>
		</div>
EOF;
	$prepend = '<div id="'.$uid.'" class="carousel slide">
	<div class="carousel-inner">';
	$append = '</div>
	<a class="carousel-control left" href="#'.$uid.'" data-slide="prev">&lsaquo;</a>
	<a class="carousel-control right" href="#'.$uid.'" data-slide="next">&rsaquo;</a>
	</div>';
	$toret = '';
	$size = 'slideshow-mini';
	$is_first = true;
	foreach($images as $img) {
		$alt = get_post_meta($img->ID, '_wp_attachment_image_alt', true);
		$toret .= str_replace(
				array('%img%','%title%','%description%', '%active%'),
				array(
						wp_get_attachment_image(
								$img->ID,
								$size,
								false,
								array(
										'class'	=> "attachment-$size",
										'alt'   => empty($alt) ? ' ' : trim(esc_attr(strip_tags($alt))),
										'title' => empty($img->post_title) ? '' : trim(esc_attr(strip_tags($img->post_title))),
								)
						),
						get_the_title($img->ID),
						apply_filters('the_content', $img->post_content),
						($is_first) ? ' active' : ''
				),
				$tpl
		);
		$is_first = false;
	}
	return $prepend.$toret.$append;
}