Merge branch 'main' into issue-3911issue-3911

1 files changed, 378 insertions, 0 deletions

diff --git a/lib/classes/DbView.php b/lib/classes/DbView.php
new file mode 100644
index 0000000..0215f8e
--- /dev/null
+++ b/lib/classes/DbView.php
@@ -0,0 +1,378 @@
+<?php
+# Lifter002: TODO
+# Lifter007: TODO
+# Lifter003: TODO
+# Lifter010: TODO
+// +---------------------------------------------------------------------------+
+// This file is part of Stud.IP
+// DbView.php
+// Class to provide simple Views and Prepared Statements
+// Mainly for MySql, may work with other DBs (not tested)
+// Copyright (c) 2002 André Noack <andre.noack@gmx.net>
+// +---------------------------------------------------------------------------+
+// 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 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.
+// +---------------------------------------------------------------------------+
+
+
+/**
+ * Class to provide simple Views and Prepared Statements
+ *
+ * Only tested with MySql, needs MySql >= 3.23
+ * Uses DB abstraction layer of PHPLib
+ *
+ * @access   public
+ * @author   André Noack <andre.noack@gmx.net>
+ * @package  DBTools
+ */
+class DbView
+{
+    /**
+     * the processed list of queries
+     *
+     *
+     * @access   private
+     * @var      array $query_list
+     */
+    private $query_list = [];
+    /**
+     * list of parameters
+     *
+     *
+     * @access   public
+     * @var      array $params
+     */
+    public $params = [];
+
+    /**
+     * Database Object
+     *
+     *
+     * @access   private
+     * @var      object $db
+     */
+    private $db;
+    /**
+     * Database Object Type
+     *
+     * Use your subclass of db_mysql here, or pass existing object to constuctor
+     *
+     * @access   private
+     * @var      string $db_class_name
+     * @see      DbView()
+     */
+    private $db_class_name = "DB_Seminar";
+    /**
+     * Temp Table Type
+     *
+     * MyISAM is always safe, HEAP may provide better performance
+     *
+     * @access   private
+     * @var      string $temp_table_type
+     */
+    private $temp_table_type = "MyISAM";
+    /**
+     * Primary Key used in Temp Table
+     *
+     * If none is set in your view, an auto_increment row is used
+     *
+     * @access   private
+     * @var      string $pk
+     * @see      get_temp_table()
+     */
+    private $pk = "";
+    /**
+     * delete the params array after each query execution
+     *
+     *
+     * @access   public
+     * @var      boolean $auto_free_params
+     */
+    public $auto_free_params = true;
+    /**
+     * turn on/off debugging
+     *
+     *
+     * @access   public
+     * @var      boolean $debug
+     */
+    public $debug = false;
+
+    static protected $dbviewfiles = [];
+
+    static protected $dbviews = [];
+
+    public static function addView($view)
+    {
+        $view = mb_strtolower($view);
+        if (!isset(self::$dbviewfiles[$view])) {
+            self::$dbviewfiles[$view] = 0;
+        }
+    }
+
+    /**
+     * Convenience method that combines addView() and returns an instance.
+     *
+     * @param String $view Required view (at least this will be present in the
+     *                     returned instance)
+     * @param mixed  $db classname of db abstraction or existing db object
+     *
+     * @return DbView Instance of self with at least the required view loaded
+     */
+    public static function getView($view, $db = '')
+    {
+        self::addView($view);
+
+        return new self($db);
+    }
+
+    /**
+     * Constructor
+     *
+     * Pass nothing to use a new instance of db_class_name, the classname for a new instance, or existing instance
+     *
+     * @access   public
+     *
+     * @param    mixed $db classname of used db abstraction or existing db object
+     */
+    public function __construct($db = "")
+    {
+        if (is_object($db)) {
+            $this->db = $db;
+        } else if ($db != "") {
+            $this->db            = new $db;
+            $this->db_class_name = $db;
+        } else {
+            $this->db = new $this->db_class_name;
+        }
+        $this->init_views();
+    }
+
+    public function init_views()
+    {
+        foreach (self::$dbviewfiles as $view => $status) {
+            if ($status === 0) {
+                $views = include 'lib/dbviews/' . $view . '.view.php';
+                self::$dbviews += $views;
+
+                self::$dbviewfiles[$view] = 1;
+            }
+        }
+    }
+
+    public function __get($view)
+    {
+        if (isset(self::$dbviews[$view])) {
+            return self::$dbviews[$view];
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * print error message and exit script
+     *
+     * @access   private
+     *
+     * @param    string $msg the message to print
+     */
+    public function halt($msg)
+    {
+        echo "<hr>$msg<hr>";
+        if ($this->debug) {
+            echo "<pre>";
+            print_r($this);
+            echo "</pre>";
+        }
+        die;
+    }
+
+    public function get_query()
+    {
+        $parsed_query = $this->get_parsed_query(func_get_args());
+        $this->db->query($parsed_query);
+        return $this->db;
+    }
+
+    public function get_parsed_query($query_list)
+    {
+        $parsed_query     = "";
+        $this->query_list = [];
+        (is_array($query_list)) ? $this->query_list = $query_list : $this->query_list[] = $query_list;
+        if (count($this->query_list) == 1) {
+            $spl = explode(":", $this->query_list[0]);
+            if ($spl[0] == "view") {
+                $this->query_list = $this->get_view(trim($spl[1]));
+            }
+        }
+        $this->parse_query($this->query_list);
+        if (is_array($this->query_list)) {
+            $parsed_query = $this->query_list[0];
+        } else {
+            $parsed_query = $this->query_list;
+        }
+
+        return $parsed_query;
+    }
+
+
+    public function parse_query(&$query)
+    {
+        if (is_array($query)) {
+            for ($i = (count($query) - 1); $i > 0; --$i) {
+                $spl = explode(":", $query[$i]);
+                if ($spl[0] == "view") {
+                    $query[$i] = $this->get_view(trim($spl[1]), $spl[2]);
+                }
+                $query[$i]  = $this->parse_query($query[$i]);
+                $repl_query = (is_array($query[$i])) ? $query[$i][0] : $query[$i];
+                for ($j = 0; $j < $i; ++$j) {
+                    $spl = mb_stristr($query[$j], "where");
+                    if (!$spl)
+                        $spl = mb_stristr($query[$j], "having");
+                    if ($spl) {
+                        $pos = mb_strpos($spl, "{" . $i . "}");
+                        if (!$pos === false)
+                            $repl_query = $this->get_temp_values($repl_query);
+                    }
+                    if (!$spl OR $pos === false) {
+                        $pos = mb_strpos($query[$j], "{" . $i . "}");
+                        if (!$pos === false)
+                            $repl_query = $this->get_temp_table($repl_query);
+                    }
+                    $query[$j] = str_replace("{" . $i . "}", $repl_query, $query[$j]);
+                }
+            }
+        }
+
+        return $query;
+    }
+
+
+    public function get_temp_table($sub_query)
+    {
+        $id    = self::get_uniqid();
+        $pk    = $this->pk ? "PRIMARY KEY($this->pk)" : "auto_" . $id . " INT NOT NULL AUTO_INCREMENT PRIMARY KEY";
+        $query = "CREATE TEMPORARY TABLE temp_$id ($pk) ENGINE=$this->temp_table_type $sub_query";
+        $this->db->query($query);
+
+        return " temp_" . $id . " ";
+    }
+
+
+    public function get_temp_values($sub_query)
+    {
+        $this->db->query($sub_query);
+        if (!$this->db->num_rows())
+            $this->halt("Sub Query: <b>$sub_query</b> returns nothing!");
+        else {
+            while ($this->db->next_record()) {
+                $result[] = $this->db->Record[0];
+            }
+            $value_list = $this->get_value_list($result);
+        }
+
+        return $value_list;
+    }
+
+    public static function get_uniqid()
+    {
+        mt_srand((double)microtime() * 1000000);
+
+        return md5(uniqid(mt_rand(), 1));
+    }
+
+    public function get_value_list($list)
+    {
+        $value_list = false;
+        if (count($list) == 1)
+            $value_list = "'$list[0]'";
+        else
+            $value_list = "'" . join("','", $list) . "'";
+
+        return $value_list;
+    }
+
+    public function get_view($name)
+    {
+        if (!empty(self::$dbviews[$name]["pk"])) {
+            $this->pk = self::$dbviews[$name]["pk"];
+        }
+        if (!empty(self::$dbviews[$name]["temp_table_type"])) {
+            $this->temp_table_type = self::$dbviews[$name]["temp_table_type"];
+        }
+        if (!$query_list = self::$dbviews[$name]["query"])
+            $this->halt("View not found: $name");
+        (is_array($query_list)) ? $query = $query_list[0] : $query = $query_list;
+        $tokens = preg_split("/[\?§\&]/u", $query);
+        if (count($tokens) > 1) {
+            $types = [];
+            $token = 0;
+            foreach (preg_split('//u', $query, null, PREG_SPLIT_NO_EMPTY) as $i => $c) {
+                switch ($c) {
+                    case '?':
+                        $types[$token++] = 1;
+                        break;
+                    case '§':
+                        $types[$token++] = 2;
+                        break;
+                    case '&':
+                        $types[$token++] = 3;
+                        break;
+                }
+            }
+            if (count($this->params) != count($types))
+                $this->halt("Wrong parameter count in view: $name");
+            $query = "";
+            for ($i = 0; $i < count($this->params); ++$i) {
+                $query .= $tokens[$i];
+                if (is_null($this->params[$i])) {
+                    $query .= 'NULL';
+                } else {
+                    switch ($types[$i]) {
+                        case 1:
+                            $query .= "'" . $this->params[$i] . "'";
+                            break;
+                        case 2:
+                            $query .= $this->params[$i];
+                            break;
+                        case 3:
+                            $query .= (is_array($this->params[$i])) ? "'" . join("','", $this->params[$i]) . "'" : "'" . $this->params[$i] . "'";
+                            break;
+                    }
+                }
+            }
+            $query .= $tokens[$i];
+            if ($this->auto_free_params)
+                $this->params = [];
+        }
+        (is_array($query_list)) ? $query_list[0] = $query : $query_list = $query;
+        return $query_list;
+    }
+
+    public function Get_union()
+    {
+        $queries     = func_get_args();
+        $view        = new DbView();
+        $union_table = $view->get_temp_table($view->get_parsed_query($queries[0]));
+        if ($queries[1]) {
+            for ($i = 1; $i < count($queries); ++$i) {
+                $view->db->query("REPLACE INTO $union_table " . $view->get_parsed_query($queries[$i]));
+            }
+        }
+
+        return $union_table;
+    }
+}
+
+?>