+<?php
+//
+// Pear DB Pager - Retrieve and return information of databases
+// result sets
+//
+// Copyright (C) 2001 Tomas Von Veschler Cox <cox@idecnet.com>
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+//
+//
+// $Id$
+
+require_once 'PEAR.php';
+require_once 'DB.php';
+
+/**
+* This class handles all the stuff needed for displaying paginated results
+* from a database query of Pear DB, in a very easy way.
+* Documentation and examples of use, can be found in:
+* http://vulcanonet.com/soft/pager/ (could be outdated)
+*
+* IMPORTANT!
+* Since PEAR DB already support native row limit (more fast and avaible in
+* all the drivers), there is no more need to use $pager->build() or
+* the $pager->fetch*() methods.
+*
+* Usage example:
+*
+*< ?php
+* require_once 'DB/Pager.php';
+* $db = DB::connect('your DSN string');
+* $from = 0; // The row to start to fetch from (you might want to get this
+* // param from the $_GET array
+* $limit = 10; // The number of results per page
+* $maxpages = 10; // The number of pages for displaying in the pager (optional)
+* $res = $db->limitQuery($sql, $from, $limit);
+* $nrows = 0; // Alternative you could use $res->numRows()
+* while ($row = $res->fetchrow()) {
+* // XXX code for building the page here
+* $nrows++;
+* }
+* $data = DB_Pager::getData($from, $limit, $nrows, $maxpages);
+* // XXX code for building the pager here
+* ? >
+*
+* @version 0.7
+* @author Tomas V.V.Cox <cox@idecnet.com>
+* @see http://vulcanonet.com/soft/pager/
+*/
+
+class MECON_DB_Pager extends PEAR
+{
+
+ /**
+ * Constructor
+ *
+ * Gets all the data needed to paginate results
+ * The object has this properties:
+ *
+ * 'current' => X, // current page you are
+ * 'numrows' => X, // total number of results
+ * 'next' => X, // row number where next page starts
+ * 'prev' => X, // row number where prev page starts
+ * 'remain' => X, // number of results remaning *in next page*
+ * 'numpages'=> X, // total number of pages
+ * 'from' => X, // the row to start fetching
+ * 'to' => X, // the row to stop fetching
+ * 'limit' => X, // how many results per page
+ * 'maxpages' => X, // how many pages to show (google style)
+ * 'firstpage' => X, // the row number of the first page
+ * 'lastpage' => X, // the row number where the last page starts
+ * 'pages' => array( // assoc with page "number => start row"
+ * 1 => X,
+ * 2 => X,
+ * 3 => X
+ * )
+ * );
+
+ * @param object $res A DB_result object from Pear_DB
+ * @param int $from The row to start fetching
+ * @param int $limit How many results per page
+ * @param int $maxpages Maximum pages to display
+ * @param int $numrows Pager will automatically
+ * find this param if is not given. If your Pear_DB backend extension
+ * doesn't support numrows(), you can manually calculate it
+ * and supply later to the constructor
+ * @deprecated
+ */
+ function MECON_DB_Pager (&$res, $from = 0, $limit = 10, $maxpages = 21, $numrows = null)
+ {
+ $this->res = $res;
+ $this->from = $from;
+ $this->limit = $limit;
+ $this->numrows = $numrows;
+ $this->maxpages = $maxpages;
+ $this->build();
+ }
+
+ /**
+ * Calculates all the data needed by Pager to work
+ * @return mixed PEAR_Error if error.
+ */
+ function build()
+ {
+ // if there is no numrows given, calculate it
+ if ($this->numrows === null) {
+ $this->numrows = $this->res->numrows();
+ if (DB::isError($this->numrows)) {
+ return $this->numrows;
+ }
+ }
+ // Si no hay resultados no se hace nada.
+ if (empty($this->numrows) or ($this->numrows < 0)) {
+ return;
+ }
+ $this->from = empty($this->from) ? 0 : $this->from;
+
+ if ($this->limit <= 0) {
+ return PEAR::raiseError (null, 'wrong "limit" param', null,
+ null, null, 'DB_Error', true);
+ }
+
+ // Total number of pages
+ $this->numpages = ceil($this->numrows/$this->limit);
+
+ // first & last page
+ $this->firstpage = 1;
+ $this->lastpage = $this->numpages;
+
+ // Build pages array
+ $this->pages = array();
+ for ($i = 1; $i <= $this->numpages; $i++) {
+ $offset = $this->limit * ($i - 1);
+ $this->pages[$i] = $offset;
+ // $from must point to one page
+ if ($this->from == $offset) {
+ // The current page we are
+ $this->currentpage = $i;
+ }
+ }
+ if (!isset($this->currentpage)) {
+ return PEAR::raiseError (null, 'wrong "from" param', null,
+ null, null, 'DB_Error', true);
+ }
+
+ // Limit number of pages (goole algoritm)
+ if ($this->maxpages) {
+ $radio = floor($this->maxpages/2);
+ $this->firstpage = $this->currentpage - $radio;
+ if (!($this->maxpages % 2)) {
+ $this->firstpage++;
+ }
+ if ($this->firstpage < 1) {
+ $this->firstpage = 1;
+ }
+ $this->lastpage = $this->currentpage + $radio;
+ if ($this->lastpage > $this->numpages) {
+ $this->lastpage = $this->numpages;
+ }
+ foreach (range($this->firstpage, $this->lastpage) as $page) {
+ $tmp[$page] = $this->pages[$page];
+ }
+ $this->pages = $tmp;
+ }
+
+ // Prev link
+ $this->prev = $this->from - $this->limit;
+ $this->prev = ($this->prev >= 0) ? $this->prev : null;
+
+ // Next link
+ $this->next = $this->from + $this->limit;
+ $this->next = ($this->next < $this->numrows) ? $this->next : null;
+
+ // Results remaining in next page & Last row to fetch
+ if ($this->currentpage == $this->numpages) {
+ $this->remain = 0;
+ $this->to = $this->numrows;
+ } else {
+ if ($this->currentpage == ($this->numpages - 1)) {
+ $this->remain = $this->numrows - ($this->limit * ($this->numpages - 1));
+ } else {
+ $this->remain = $this->limit;
+ }
+ $this->to = $this->currentpage * $this->limit;
+ }
+
+ // Current item (when fetching).
+ $this->current = $this->from - 1;
+ }
+
+ function fetchRow($mode=DB_FETCHMODE_DEFAULT)
+ {
+ $this->current++;
+ if ($this->current >= $this->to) {
+ return null;
+ }
+ return $this->res->fetchRow($mode, $this->current);
+ }
+
+ function fetchInto(&$arr, $mode=DB_FETCHMODE_DEFAULT)
+ {
+ $this->current++;
+ if ($this->current >= $this->to) {
+ return null;
+ }
+ return $this->res->fetchInto($arr, $mode, $this->current);
+ }
+}
+?>
projects / mecon / meconlib.git / commitdiff