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Diffstat (limited to 'phpBB/phpbb/pagination.php')
| -rw-r--r-- | phpBB/phpbb/pagination.php | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/phpBB/phpbb/pagination.php b/phpBB/phpbb/pagination.php new file mode 100644 index 0000000000..57e7932341 --- /dev/null +++ b/phpBB/phpbb/pagination.php @@ -0,0 +1,295 @@ +<?php +/** +* +* @package phpbb +* @copyright (c) 2013 phpBB Group +* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2 +* +*/ + +namespace phpbb; + +class pagination +{ + /** @var \phpbb\template\template */ + protected $template; + + /** @var \phpbb\user */ + protected $user; + + /** + * Constructor + * + * @param \phpbb\template\template $template + * @param \phpbb\user $user + */ + public function __construct(\phpbb\template\template $template, \phpbb\user $user) + { + $this->template = $template; + $this->user = $user; + } + + /** + * Generate a pagination link based on the url and the page information + * + * @param string $base_url is url prepended to all links generated within the function + * If you use page numbers inside your controller route, base_url should contains a placeholder (%d) + * for the page. Also be sure to specify the pagination path information into the start_name argument + * @param string $on_page is the page for which we want to generate the link + * @param string $start_name is the name of the parameter containing the first item of the given page (example: start=20) + * If you use page numbers inside your controller route, start name should be the string + * that should be removed for the first page (example: /page/%d) + * @param int $per_page the number of items, posts, etc. to display per page, used to determine the number of pages to produce + * @return URL for the requested page + */ + protected function generate_page_link($base_url, $on_page, $start_name, $per_page) + { + if (strpos($start_name, '%d') !== false) + { + return ($on_page > 1) ? sprintf($base_url, (int) $on_page) : str_replace($start_name, '', $base_url); + } + else + { + $url_delim = (strpos($base_url, '?') === false) ? '?' : ((strpos($base_url, '?') === strlen($base_url) - 1) ? '' : '&'); + return ($on_page > 1) ? $base_url . $url_delim . $start_name . '=' . (($on_page - 1) * $per_page) : $base_url; + } + } + + /** + * Generate template rendered pagination + * Allows full control of rendering of pagination with the template + * + * @param string $base_url is url prepended to all links generated within the function + * If you use page numbers inside your controller route, base_url should contains a placeholder (%d) + * for the page. Also be sure to specify the pagination path information into the start_name argument + * @param string $block_var_name is the name assigned to the pagination data block within the template (example: <!-- BEGIN pagination -->) + * @param string $start_name is the name of the parameter containing the first item of the given page (example: start=20) + * If you use page numbers inside your controller route, start name should be the string + * that should be removed for the first page (example: /page/%d) + * @param int $num_items the total number of items, posts, etc., used to determine the number of pages to produce + * @param int $per_page the number of items, posts, etc. to display per page, used to determine the number of pages to produce + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @param bool $reverse_count determines whether we weight display of the list towards the start (false) or end (true) of the list + * @param bool $ignore_on_page decides whether we enable an active (unlinked) item, used primarily for embedded lists + * @return null + */ + public function generate_template_pagination($base_url, $block_var_name, $start_name, $num_items, $per_page, $start = 1, $reverse_count = false, $ignore_on_page = false) + { + $total_pages = ceil($num_items / $per_page); + $on_page = $this->get_on_page($per_page, $start); + $u_previous_page = $u_next_page = ''; + + if ($total_pages > 1) + { + if ($reverse_count) + { + $start_page = ($total_pages > 5) ? $total_pages - 4 : 1; + $end_page = $total_pages; + } + else + { + // What we're doing here is calculating what the "start" and "end" pages should be. We + // do this by assuming pagination is "centered" around the currently active page with + // the three previous and three next page links displayed. Anything more than that and + // we display the ellipsis, likewise anything less. + // + // $start_page is the page at which we start creating the list. When we have five or less + // pages we start at page 1 since there will be no ellipsis displayed. Anymore than that + // and we calculate the start based on the active page. This is the min/max calculation. + // First (max) would we end up starting on a page less than 1? Next (min) would we end + // up starting so close to the end that we'd not display our minimum number of pages. + // + // $end_page is the last page in the list to display. Like $start_page we use a min/max to + // determine this number. Again at most five pages? Then just display them all. More than + // five and we first (min) determine whether we'd end up listing more pages than exist. + // We then (max) ensure we're displaying the minimum number of pages. + $start_page = ($total_pages > 5) ? min(max(1, $on_page - 3), $total_pages - 4) : 1; + $end_page = ($total_pages > 5) ? max(min($total_pages, $on_page + 3), 5) : $total_pages; + } + + if ($on_page != 1) + { + $u_previous_page = $this->generate_page_link($base_url, $on_page - 1, $start_name, $per_page); + + $this->template->assign_block_vars($block_var_name, array( + 'PAGE_NUMBER' => '', + 'PAGE_URL' => $u_previous_page, + 'S_IS_CURRENT' => false, + 'S_IS_PREV' => true, + 'S_IS_NEXT' => false, + 'S_IS_ELLIPSIS' => false, + )); + } + + // This do...while exists purely to negate the need for start and end assign_block_vars, i.e. + // to display the first and last page in the list plus any ellipsis. We use this loop to jump + // around a little within the list depending on where we're starting (and ending). + $at_page = 1; + do + { + // We decide whether to display the ellipsis during the loop. The ellipsis is always + // displayed as either the second or penultimate item in the list. So are we at either + // of those points and of course do we even need to display it, i.e. is the list starting + // on at least page 3 and ending three pages before the final item. + $this->template->assign_block_vars($block_var_name, array( + 'PAGE_NUMBER' => $at_page, + 'PAGE_URL' => $this->generate_page_link($base_url, $at_page, $start_name, $per_page), + 'S_IS_CURRENT' => (!$ignore_on_page && $at_page == $on_page), + 'S_IS_NEXT' => false, + 'S_IS_PREV' => false, + 'S_IS_ELLIPSIS' => ($at_page == 2 && $start_page > 2) || ($at_page == $total_pages - 1 && $end_page < $total_pages - 1), + )); + + // We may need to jump around in the list depending on whether we have or need to display + // the ellipsis. Are we on page 2 and are we more than one page away from the start + // of the list? Yes? Then we jump to the start of the list. Likewise are we at the end of + // the list and are there more than two pages left in total? Yes? Then jump to the penultimate + // page (so we can display the ellipsis next pass). Else, increment the counter and keep + // going + if ($at_page == 2 && $at_page < $start_page - 1) + { + $at_page = $start_page; + } + else if ($at_page == $end_page && $end_page < $total_pages - 1) + { + $at_page = $total_pages - 1; + } + else + { + $at_page++; + } + } + while ($at_page <= $total_pages); + + if ($on_page != $total_pages) + { + $u_next_page = $this->generate_page_link($base_url, $on_page + 1, $start_name, $per_page); + + $this->template->assign_block_vars($block_var_name, array( + 'PAGE_NUMBER' => '', + 'PAGE_URL' => $u_next_page, + 'S_IS_CURRENT' => false, + 'S_IS_PREV' => false, + 'S_IS_NEXT' => true, + 'S_IS_ELLIPSIS' => false, + )); + } + } + + // If the block_var_name is a nested block, we will use the last (most + // inner) block as a prefix for the template variables. If the last block + // name is pagination, the prefix is empty. If the rest of the + // block_var_name is not empty, we will modify the last row of that block + // and add our pagination items. + $tpl_block_name = $tpl_prefix = ''; + if (strrpos($block_var_name, '.') !== false) + { + $tpl_block_name = substr($block_var_name, 0, strrpos($block_var_name, '.')); + $tpl_prefix = strtoupper(substr($block_var_name, strrpos($block_var_name, '.') + 1)); + } + else + { + $tpl_prefix = strtoupper($block_var_name); + } + $tpl_prefix = ($tpl_prefix == 'PAGINATION') ? '' : $tpl_prefix . '_'; + + $template_array = array( + $tpl_prefix . 'BASE_URL' => $base_url, + $tpl_prefix . 'PER_PAGE' => $per_page, + 'U_' . $tpl_prefix . 'PREVIOUS_PAGE' => ($on_page != 1) ? $u_previous_page : '', + 'U_' . $tpl_prefix . 'NEXT_PAGE' => ($on_page != $total_pages) ? $u_next_page : '', + $tpl_prefix . 'TOTAL_PAGES' => $total_pages, + $tpl_prefix . 'CURRENT_PAGE' => $on_page, + $tpl_prefix . 'PAGE_NUMBER' => $this->on_page($num_items, $per_page, $start), + ); + + if ($tpl_block_name) + { + $this->template->alter_block_array($tpl_block_name, $template_array, true, 'change'); + } + else + { + $this->template->assign_vars($template_array); + } + } + + /** + * Get current page number + * + * @param int $per_page the number of items, posts, etc. per page + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @return int Current page number + */ + public function get_on_page($per_page, $start) + { + return floor($start / $per_page) + 1; + } + + /** + * Return current page + * + * @param int $num_items the total number of items, posts, topics, etc. + * @param int $per_page the number of items, posts, etc. per page + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @return string Descriptive pagination string (e.g. "page 1 of 10") + */ + public function on_page($num_items, $per_page, $start) + { + $on_page = $this->get_on_page($per_page, $start); + return $this->user->lang('PAGE_OF', $on_page, max(ceil($num_items / $per_page), 1)); + } + + /** + * Get current page number + * + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @param int $per_page the number of items, posts, etc. per page + * @param int $num_items the total number of items, posts, topics, etc. + * @return int Current page number + */ + public function validate_start($start, $per_page, $num_items) + { + if ($start < 0 || $start >= $num_items) + { + return ($start < 0 || $num_items <= 0) ? 0 : floor(($num_items - 1) / $per_page) * $per_page; + } + + return $start; + } + + /** + * Get new start when searching from the end + * + * If the user is trying to reach late pages, start searching from the end. + * + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @param int $limit the number of items, posts, etc. to display + * @param int $num_items the total number of items, posts, topics, etc. + * @return int Current page number + */ + public function reverse_start($start, $limit, $num_items) + { + return max(0, $num_items - $limit - $start); + } + + /** + * Get new item limit when searching from the end + * + * If the user is trying to reach late pages, start searching from the end. + * In this case the items to display might be lower then the actual per_page setting. + * + * @param int $start the item which should be considered currently active, used to determine the page we're on + * @param int $per_page the number of items, posts, etc. per page + * @param int $num_items the total number of items, posts, topics, etc. + * @return int Current page number + */ + public function reverse_limit($start, $per_page, $num_items) + { + if ($start + $per_page > $num_items) + { + return min($per_page, max(1, $num_items - $start)); + } + + return $per_page; + } +} |