3 // Pear DB Pager - Retrieve and return information of databases
6 // Copyright (C) 2001 Tomas Von Veschler Cox <cox@idecnet.com>
8 // This library is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU Lesser General Public
10 // License as published by the Free Software Foundation; either
11 // version 2.1 of the License, or (at your option) any later version.
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // Lesser General Public License for more details.
18 // You should have received a copy of the GNU Lesser General Public
19 // License along with this library; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 // Based on DB_Pager 0.7 from the pear.php.net repository.
26 // The only modifications made have been modification of the include paths.
28 // From Pear CVS: Id: Pager.php,v 1.3 2002/05/12 13:59:40 cox Exp
30 require_once 'PEAR.php';
31 require_once 'DB.php';
34 * This class handles all the stuff needed for displaying paginated results
35 * from a database query of Pear DB, in a very easy way.
36 * Documentation and examples of use, can be found in:
37 * http://vulcanonet.com/soft/pager/ (could be outdated)
40 * Since PEAR DB already support native row limit (more fast and avaible in
41 * all the drivers), there is no more need to use $pager->build() or
42 * the $pager->fetch*() methods.
47 * require_once 'DB/Pager.php';
48 * $db = DB::connect('your DSN string');
49 * $from = 0; // The row to start to fetch from (you might want to get this
50 * // param from the $_GET array
51 * $limit = 10; // The number of results per page
52 * $maxpages = 10; // The number of pages for displaying in the pager (optional)
53 * $res = $db->limitQuery($sql, $from, $limit);
54 * $nrows = 0; // Alternative you could use $res->numRows()
55 * while ($row = $res->fetchrow()) {
56 * // XXX code for building the page here
59 * $data = DB_Pager::getData($from, $limit, $nrows, $maxpages);
60 * // XXX code for building the pager here
64 * @author Tomas V.V.Cox <cox@idecnet.com>
65 * @see http://vulcanonet.com/soft/pager/
68 class DB_Pager extends PEAR
74 * @param object $res A DB_result object from Pear_DB
75 * @param int $from The row to start fetching
76 * @param int $limit How many results per page
77 * @param int $numrows Pager will automatically
78 * find this param if is not given. If your Pear_DB backend extension
79 * doesn't support numrows(), you can manually calculate it
80 * and supply later to the constructor
83 function DB_Pager (&$res, $from, $limit, $numrows = null)
87 $this->limit = $limit;
88 $this->numrows = $numrows;
92 * Calculates all the data needed by Pager to work
94 * @return mixed An assoc array with all the data (see getData)
95 * or DB_Error on error
96 * @see DB_Pager::getData
101 // if there is no numrows given, calculate it
102 if ($this->numrows === null) {
103 $this->numrows = $this->res->numrows();
104 if (DB::isError($this->numrows)) {
105 return $this->numrows;
108 $data = $this->getData($this->from, $this->limit, $this->numrows);
109 if (DB::isError($data)) {
112 $this->current = $this->from - 1;
113 $this->top = $data['to'];
120 function fetchRow($mode=DB_FETCHMODE_DEFAULT)
123 if ($this->current >= $this->top) {
126 return $this->res->fetchRow($mode, $this->current);
132 function fetchInto(&$arr, $mode=DB_FETCHMODE_DEFAULT)
135 if ($this->current >= $this->top) {
138 return $this->res->fetchInto($arr, $mode, $this->current);
142 * Gets all the data needed to paginate results
143 * This is an associative array with the following
147 * 'current' => X, // current page you are
148 * 'numrows' => X, // total number of results
149 * 'next' => X, // row number where next page starts
150 * 'prev' => X, // row number where prev page starts
151 * 'remain' => X, // number of results remaning *in next page*
152 * 'numpages'=> X, // total number of pages
153 * 'from' => X, // the row to start fetching
154 * 'to' => X, // the row to stop fetching
155 * 'limit' => X, // how many results per page
156 * 'maxpages' => X, // how many pages to show (google style)
157 * 'firstpage' => X, // the row number of the first page
158 * 'lastpage' => X, // the row number where the last page starts
159 * 'pages' => array( // assoc with page "number => start row"
165 * @param int $from The row to start fetching
166 * @param int $limit How many results per page
167 * @param int $numrows Number of results from query
169 * @return array associative array with data or DB_error on error
172 function &getData($from, $limit, $numrows, $maxpages = false)
174 if (empty($numrows) || ($numrows < 0)) {
177 $from = (empty($from)) ? 0 : $from;
180 return PEAR::raiseError (null, 'wrong "limit" param', null,
181 null, null, 'DB_Error', true);
184 // Total number of pages
185 $pages = ceil($numrows/$limit);
186 $data['numpages'] = $pages;
189 $data['firstpage'] = 1;
190 $data['lastpage'] = $pages;
193 $data['pages'] = array();
194 for ($i=1; $i <= $pages; $i++) {
195 $offset = $limit * ($i-1);
196 $data['pages'][$i] = $offset;
197 // $from must point to one page
198 if ($from == $offset) {
199 // The current page we are
200 $data['current'] = $i;
203 if (!isset($data['current'])) {
204 return PEAR::raiseError (null, 'wrong "from" param', null,
205 null, null, 'DB_Error', true);
208 // Limit number of pages (goole algoritm)
210 $radio = floor($maxpages/2);
211 $minpage = $data['current'] - $radio;
215 $maxpage = $data['current'] + $radio - 1;
216 if ($maxpage > $data['numpages']) {
217 $maxpage = $data['numpages'];
219 foreach (range($minpage, $maxpage) as $page) {
220 $tmp[$page] = $data['pages'][$page];
222 $data['pages'] = $tmp;
223 $data['maxpages'] = $maxpages;
225 $data['maxpages'] = null;
229 $prev = $from - $limit;
230 $data['prev'] = ($prev >= 0) ? $prev : null;
233 $next = $from + $limit;
234 $data['next'] = ($next < $numrows) ? $next : null;
236 // Results remaining in next page & Last row to fetch
237 if ($data['current'] == $pages) {
239 $data['to'] = $numrows;
241 if ($data['current'] == ($pages - 1)) {
242 $data['remain'] = $numrows - ($limit*($pages-1));
244 $data['remain'] = $limit;
246 $data['to'] = $data['current'] * $limit;
248 $data['numrows'] = $numrows;
249 $data['from'] = $from + 1;
250 $data['limit'] = $limit;