classes/plfilter.php

   1 <?php
   2 /***************************************************************************
   3  *  Copyright (C) 2003-2010 Polytechnique.org                              *
   4  *  http://opensource.polytechnique.org/                                   *
   5  *                                                                         *
   6  *  This program is free software; you can redistribute it and/or modify   *
   7  *  it under the terms of the GNU General Public License as published by   *
   8  *  the Free Software Foundation; either version 2 of the License, or      *
   9  *  (at your option) any later version.                                    *
  10  *                                                                         *
  11  *  This program is distributed in the hope that it will be useful,        *
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
  14  *  GNU General Public License for more details.                           *
  15  *                                                                         *
  16  *  You should have received a copy of the GNU General Public License      *
  17  *  along with this program; if not, write to the Free Software            *
  18  *  Foundation, Inc.,                                                      *
  19  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA                *
  20  ***************************************************************************/
  21
  22 class PlLimit
  23 {
  24     private $count = null;
  25     private $from  = null;
  26
  27     public function __construct($count = null, $from = null)
  28     {
  29         $this->count = $count;
  30         $this->from  = $from;
  31     }
  32
  33     public function getSql()
  34     {
  35         if (!is_null($this->count)) {
  36             if (!is_null($this->from) && $this->from != 0) {
  37                 return XDB::format('LIMIT {?}, {?}', (int)$this->from, (int)$this->count);
  38             } else {
  39                 return XDB::format('LIMIT {?}', (int)$this->count);
  40             }
  41         }
  42         return '';
  43     }
  44 }
  45
  46 class PlSqlJoin
  47 {
  48     private $mode;
  49     private $table;
  50     private $condition;
  51
  52     const MODE_LEFT  = 'LEFT';
  53     const MODE_RIGHT = 'RIGHT';
  54     const MODE_INNER = 'INNER';
  55
  56     public function __construct($mode, $table, $condition)
  57     {
  58         if ($mode != self::MODE_LEFT && $mode != self::MODE_RIGHT && $mode != self::MODE_INNER) {
  59             Platal::page()->kill("Join mode error : unknown mode $mode");
  60             return;
  61         }
  62         $this->mode = $mode;
  63         $this->table = $table;
  64         $this->condition = $condition;
  65     }
  66
  67     public function mode()
  68     {
  69         return $this->mode;
  70     }
  71
  72     public function table()
  73     {
  74         return $this->table;
  75     }
  76
  77     public function condition()
  78     {
  79         return $this->condition;
  80     }
  81
  82     /** Replace all "metas" in the condition with their translation.
  83      * $ME always becomes the alias of the table
  84      * @param $key The name the joined table will have in the final query
  85      * @param $joinMetas An array of meta => conversion to apply to the condition
  86      */
  87     public function replaceJoinMetas($key, $joinMetas = array())
  88     {
  89         $joinMetas['$ME'] = $key;
  90         return str_replace(array_keys($joinMetas), $joinMetas, $this->condition);
  91     }
  92
  93     /** Create a join command from an array of PlSqlJoin
  94      * @param $joins The list of 'join' to convert into an SQL query
  95      * @param $joinMetas An array of ('$META' => 'conversion') to apply to the joins.
  96      */
  97     public static function formatJoins(array $joins, array $joinMetas)
  98     {
  99         $str = '';
 100         foreach ($joins as $key => $join) {
 101             if (! ($join instanceof PlSqlJoin)) {
 102                 Platal::page()->kill("Error: not a join: $join");
 103             }
 104             $mode  = $join->mode();
 105             $table = $join->table();
 106             $str .= ' ' . $mode . ' JOIN ' . $table . ' AS ' . $key;
 107             if ($join->condition() != null) {
 108                 $str .= ' ON (' . $join->replaceJoinMetas($key, $joinMetas) . ')';
 109             }
 110             $str .= "\n";
 111         }
 112         return $str;
 113     }
 114 }
 115
 116 abstract class PlFilter
 117 {
 118     /** Filters objects matching the PlFilter
 119      * @param $objects The objects to filter
 120      * @param $limit The portion of the matching objects to show
 121      */
 122     public abstract function filter(array $objects, PlLimit &$limit);
 123
 124     public abstract function setCondition(PlFilterCondition &$cond);
 125
 126     public abstract function addSort(PlFilterOrder &$sort);
 127
 128     public abstract function getTotalCount();
 129
 130     /** Get objects, selecting only those within a limit
 131      * @param $limit The portion of the matching objects to select
 132      */
 133     public abstract function get(PlLimit &$limit);
 134
 135     /** PRIVATE FUNCTIONS
 136      */
 137
 138     /** List of metas to replace in joins:
 139      * '$COIN' => 'pan.x' means 'replace $COIN with pan.x in the condition of the joins'
 140      *
 141      * "$ME" => "joined table alias" is always added to these.
 142      */
 143     private $joinMetas = array();
 144
 145     /** Build the 'join' part of the query
 146      * This function will call all methods declared in self::$joinMethods
 147      * to get an array of PlSqlJoin objects to merge
 148      */
 149     private function buildJoins()
 150     {
 151         $joins = array();
 152         foreach ($this->$joinMethods as $method) {
 153             $joins = array_merge($joins, $this->$method());
 154         }
 155         return PlSqlJoin::formatJoins($joins, $this->$joinMetas);
 156     }
 157
 158 }
 159
 160 ?>