triplette-paginated-gallery.php

<?php
/*
Plugin Name: Triplette Paginated Gallery
Plugin URI: http://www.triplette.it
Description: Adds pagination to standard wordpress gallery
Version: 0.1.1
Author: Henry Triplette
Author URI: http://www.triplette.it
License: GPL2
*/

/*  Copyright 2014  Henry Triplette  (email : scrivi@triplette.it)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2, as
    published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

require_once(dirname(__FILE__) . '/options.php');

if (get_option('use_gallery_shortcode')) {
	// Over-ride the standard gallery shortcode with our own
	remove_shortcode('gallery');
	add_shortcode('gallery', 'triplette_paginated_gallery');
} else {
	add_shortcode('paginated-gallery', 'triplette_paginated_gallery');
}

function triplette_paginated_gallery($attr) {
	$post = get_post();

	static $instance = 0;
	$instance++;

	if ( ! empty( $attr['ids'] ) ) {
		// 'ids' is explicitly ordered, unless you specify otherwise.
		if ( empty( $attr['orderby'] ) ) {
			$attr['orderby'] = 'post__in';
		}
		$attr['include'] = $attr['ids'];
	}

	$imagesPerPage = get_option('thumbnails_per_page');

	/**
	 * Filter the default gallery shortcode output.
	 *
	 * If the filtered output isn't empty, it will be used instead of generating
	 * the default gallery template.
	 *
	 * @since 2.5.0
	 * @since 4.2.0 The `$instance` parameter was added.
	 *
	 * @see gallery_shortcode()
	 *
	 * @param string $output   The gallery output. Default empty.
	 * @param array  $attr     Attributes of the gallery shortcode.
	 * @param int    $instance Unique numeric ID of this gallery shortcode instance.
	 */
	$output = apply_filters( 'post_gallery', '', $attr, $instance );
	if ( $output != '' ) {
		// return $output;
	}

	$html5 = current_theme_supports( 'html5', 'gallery' );
	$atts = shortcode_atts( array(
		'order'      => 'ASC',
		'orderby'    => 'menu_order ID',
		'id'         => $post ? $post->ID : 0,
		'itemtag'    => $html5 ? 'figure'     : 'dl',
		'icontag'    => $html5 ? 'div'        : 'dt',
		'captiontag' => $html5 ? 'figcaption' : 'dd',
		'columns'    => 3,
		'perpage'		 => $imagesPerPage,
		'size'       => 'thumbnail',
		'include'    => '',
		'exclude'    => '',
		'link'       => ''
	), $attr, 'gallery' );

	$id = intval( $atts['id'] );

	if ( ! empty( $atts['include'] ) ) {
		$_attachments = get_posts( array( 'include' => $atts['include'], 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $atts['order'], 'orderby' => $atts['orderby'] ) );

		$attachments = array();
		foreach ( $_attachments as $key => $val ) {
			$attachments[$val->ID] = $_attachments[$key];
		}
	} elseif ( ! empty( $atts['exclude'] ) ) {
		$attachments = get_children( array( 'post_parent' => $id, 'exclude' => $atts['exclude'], 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $atts['order'], 'orderby' => $atts['orderby'] ) );
	} else {
		$attachments = get_children( array( 'post_parent' => $id, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $atts['order'], 'orderby' => $atts['orderby'] ) );
	}

	if ( empty( $attachments ) ) {
		return '';
	}

	if ( is_feed() ) {
		$output = "\n";
		foreach ( $attachments as $att_id => $attachment ) {
			$output .= wp_get_attachment_link( $att_id, $atts['size'], true ) . "\n";
		}
		return $output;
	}

	// Work out how many pages we need and what page we are currently on
	$imageCount = count($attachments);
	$pageCount = ceil($imageCount / $imagesPerPage);

	$currentPage = intval($_GET['galleryPage']);
	if ( empty($currentPage) || $currentPage<=0 ) $currentPage=1;

	$maxImage = $currentPage * $imagesPerPage;
	$minImage = ($currentPage-1) * $imagesPerPage;

	if ($pageCount > 1) {
		$page_link= get_permalink();
		$page_link_perma= true;
		if ( strpos($page_link, '?')!==false )
			$page_link_perma= false;

		$gplist= '<div class="gallery_pages_list">'.__('Gallery Page').'<hr /> <ul class="pagination pagination-sm">';
		for ( $j=1; $j<= $pageCount; $j++)
		{
			if ( $j==$currentPage ) {
				if ( $j < 10 ) { $j2 = '0'.$j; } else { $j2 = $j; }
				$gplist .= '<li class="active"><a href="#">'.$j2.' </a></li>';
			} else {
				if ( $j < 10 ) { $j2 = '0'.$j; } else { $j2 = $j; }
				$gplist .= '<li><a href="'.$page_link. ( ($page_link_perma?'?':'&amp;') ). 'galleryPage='.$j.'">'.$j2.'</a></li> ';
			}
		}

		$gplist .= '</ul></div><hr />';
	} else {
		$gplist= '';
	}

	$itemtag = tag_escape( $atts['itemtag'] );
	$captiontag = tag_escape( $atts['captiontag'] );
	$icontag = tag_escape( $atts['icontag'] );
	$valid_tags = wp_kses_allowed_html( 'post' );
	if ( ! isset( $valid_tags[ $itemtag ] ) ) {
		$itemtag = 'dl';
	}
	if ( ! isset( $valid_tags[ $captiontag ] ) ) {
		$captiontag = 'dd';
	}
	if ( ! isset( $valid_tags[ $icontag ] ) ) {
		$icontag = 'dt';
	}

	$columns = intval( $atts['columns'] );
	$itemwidth = $columns > 0 ? floor(100/$columns) : 100;
	$float = is_rtl() ? 'right' : 'left';

	$selector = "gallery-{$instance}";

	$gallery_style = '';

	/**
	 * Filter whether to print default gallery styles.
	 *
	 * @since 3.1.0
	 *
	 * @param bool $print Whether to print default gallery styles.
	 *                    Defaults to false if the theme supports HTML5 galleries.
	 *                    Otherwise, defaults to true.
	 */
	if ( apply_filters( 'use_default_gallery_style', ! $html5 ) ) {
		$gallery_style = "
		<style type='text/css'>
			#{$selector} {
				margin: auto;
			}
			#{$selector} .gallery-item {
				float: {$float};
				margin-top: 10px;
				text-align: center;
				width: {$itemwidth}%;
			}
			#{$selector} img {
				border: 2px solid #cfcfcf;
			}
			#{$selector} .gallery-caption {
				margin-left: 0;
			}
			/* see gallery_shortcode() in wp-includes/media.php */
		</style>\n\t\t";
	}

	$size_class = sanitize_html_class( $atts['size'] );
	$gallery_div = "<div id='$selector' class='gallery galleryid-{$id} gallery-columns-{$columns} gallery-size-{$size_class}'>";

	/**
	 * Filter the default gallery shortcode CSS styles.
	 *
	 * @since 2.5.0
	 *
	 * @param string $gallery_style Default CSS styles and opening HTML div container
	 *                              for the gallery shortcode output.
	 */
	$output = apply_filters( 'gallery_style', $gallery_style . $gallery_div );

	$i = 0;
	$k = 0;
	foreach ( $attachments as $id => $attachment ) {
		if ($k >= $minImage && $k < $maxImage) {
			$attr = ( trim( $attachment->post_excerpt ) ) ? array( 'aria-describedby' => "$selector-$id" ) : '';
			if ( ! empty( $atts['link'] ) && 'file' === $atts['link'] ) {
				$image_output = wp_get_attachment_link( $id, $atts['size'], false, false, false, $attr );
			} elseif ( ! empty( $atts['link'] ) && 'none' === $atts['link'] ) {
				$image_output = wp_get_attachment_image( $id, $atts['size'], false, $attr );
			} else {
				$image_output = wp_get_attachment_link( $id, $atts['size'], true, false, false, $attr );
			}
			$image_meta  = wp_get_attachment_metadata( $id );

			$orientation = '';
			if ( isset( $image_meta['height'], $image_meta['width'] ) ) {
				$orientation = ( $image_meta['height'] > $image_meta['width'] ) ? 'portrait' : 'landscape';
			}
			$output .= "<{$itemtag} class='gallery-item'>";
			$output .= "
				<{$icontag} class='gallery-icon {$orientation}'>
					$image_output
				</{$icontag}>";
			if ( $captiontag && trim($attachment->post_excerpt) ) {
				$output .= "
					<{$captiontag} class='wp-caption-text gallery-caption' id='$selector-$id'>
					" . wptexturize($attachment->post_excerpt) . "
					</{$captiontag}>";
			}
			$output .= "</{$itemtag}>";
			if ( ! $html5 && $columns > 0 && ++$i % $columns == 0 ) {
				$output .= '<br style="clear: both" />';
			}

		}
		$k++;
	}

	if ( ! $html5 && $columns > 0 && $i % $columns !== 0 ) {
		$output .= "
			<br style='clear: both' />";
	}

	$output .= "
		</div>\n";

	$output .= "\n$gplist\n";

	// If we've got this far then we must have some attachments to play with!
	// $output .= 'Gallery Here - Page '. $currentPage. ' of '. $pageCount;

	return $output;
}

?>