+<?php
+/***************************************************************************
+ * Copyright (C) 2003-2010 Polytechnique.org *
+ * http://opensource.polytechnique.org/ *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License as published by *
+ * the Free Software Foundation; either version 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * 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., *
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
+ ***************************************************************************/
+
+// {{{ interface PlFilterCondition
+interface PlFilterCondition
+{
+ const COND_TRUE = 'TRUE';
+ const COND_FALSE = 'FALSE';
+
+ public function buildCondition(PlFilter &$pf);
+}
+// }}}
+
+// {{{ class PFC_OneChild
+abstract class PFC_OneChild implements PlFilterCondition
+{
+ protected $child;
+
+ public function __construct($child = null)
+ {
+ if (!is_null($child) && ($child instanceof PlFilterCondition)) {
+ $this->setChild($child);
+ }
+ }
+
+ public function setChild(PlFilterCondition &$cond)
+ {
+ $this->child =& $cond;
+ }
+}
+// }}}
+
+// {{{ class PFC_NChildren
+abstract class PFC_NChildren implements PlFilterCondition
+{
+ protected $children = array();
+
+ public function __construct()
+ {
+ $children = func_get_args();
+ foreach ($children as &$child) {
+ if (!is_null($child) && ($child instanceof PlFilterCondition)) {
+ $this->addChild($child);
+ }
+ }
+ }
+
+ public function addChild(PlFilterCondition &$cond)
+ {
+ $this->children[] =& $cond;
+ }
+
+ protected function catConds(array $cond, $op, $fallback)
+ {
+ if (count($cond) == 0) {
+ return $fallback;
+ } else if (count($cond) == 1) {
+ return $cond[0];
+ } else {
+ return '(' . implode(') ' . $op . ' (', $cond) . ')';
+ }
+ }
+}
+// }}}
+
+// {{{ class PFC_True
+class PFC_True implements PlFilterCondition
+{
+ public function buildCondition(PlFilter &$uf)
+ {
+ return self::COND_TRUE;
+ }
+}
+// }}}
+
+// {{{ class PFC_False
+class PFC_False implements PlFilterCondition
+{
+ public function buildCondition(PlFilter &$uf)
+ {
+ return self::COND_FALSE;
+ }
+}
+// }}}
+
+// {{{ class PFC_Not
+class PFC_Not extends PFC_OneChild
+{
+ public function buildCondition(PlFilter &$uf)
+ {
+ $val = $this->child->buildCondition($uf);
+ if ($val == self::COND_TRUE) {
+ return self::COND_FALSE;
+ } else if ($val == self::COND_FALSE) {
+ return self::COND_TRUE;
+ } else {
+ return 'NOT (' . $val . ')';
+ }
+ }
+}
+// }}}
+
+// {{{ class PFC_And
+class PFC_And extends PFC_NChildren
+{
+ public function buildCondition(PlFilter &$uf)
+ {
+ if (empty($this->children)) {
+ return self::COND_FALSE;
+ } else {
+ $true = self::COND_FALSE;
+ $conds = array();
+ foreach ($this->children as &$child) {
+ $val = $child->buildCondition($uf);
+ if ($val == self::COND_TRUE) {
+ $true = self::COND_TRUE;
+ } else if ($val == self::COND_FALSE) {
+ return self::COND_FALSE;
+ } else {
+ $conds[] = $val;
+ }
+ }
+ return $this->catConds($conds, 'AND', $true);
+ }
+ }
+}
+// }}}
+
+// {{{ class PFC_Or
+class PFC_Or extends PFC_NChildren
+{
+ public function buildCondition(PlFilter &$uf)
+ {
+ if (empty($this->children)) {
+ return self::COND_TRUE;
+ } else {
+ $true = self::COND_TRUE;
+ $conds = array();
+ foreach ($this->children as &$child) {
+ $val = $child->buildCondition($uf);
+ if ($val == self::COND_TRUE) {
+ return self::COND_TRUE;
+ } else if ($val == self::COND_FALSE) {
+ $true = self::COND_FALSE;
+ } else {
+ $conds[] = $val;
+ }
+ }
+ return $this->catConds($conds, 'OR', $true);
+ }
+ }
+}
+// }}}
+?>