<?php
/* vim: set tabstop=4 foldmethod=marker: */

# fmplib_uservar
#
# This class implements a simple user variable storage class which can
# be used in place of phplib's user variables, which seem to have
# problems.  It requires the following table:
#
# CREATE TABLE `uservar` (
#   `username` varchar(20) default NULL,
#   `variables` blob
# ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
#
# This class is abstract and can't be called statically.  The derived
# class must define $db_classname to be a previously defined fmplib_db
# subclass with proper access tokens defined.
#
#
# It implements five simple methods:
#
# void fmplib_uservar(string $name):
#    Constructor:  This establishes and registers the name associated
#    with the stored variables.   This should generally be the
#    logged-in username, possibly concatenated with the script name.
#    All variables associated with this name in the uservar table are
#    restored and registered.
#
# void register($varname):
#    Registers the named variable and its current value in the $GLOBAL
#    array associated with the registered name of the class instance.
#    If a class derived from this class is instantiated within a
#    function call, all variables must be declared global prior to
#    calling register() on them or their value will be lost.
#
# void unregister($varname):
#    Unregisters a variable name.
#
# void freeze():
#    Deletes any variables previously stored in the database under the
#    registered name, updates the $GLOBAL array of regsiterd
#    variables, serializes it, and stores it permanently in the
#    uservar table.  This function must be called somewhere in your
#    program prior to exiting.  
#
# void thaw():
#    Restores variables associated with the regitered name, as does
#    the class constructor.  Normally this method won't be needed
#    since its functionality is a large subset of the class
#    constructor.
#

# {{{ fmplib_uservar Class

abstract class fmplib_uservar {
  
  public $username;

  protected $db_classname;
  protected $db_host;
  protected $db_database;
  protected $db_user;
  protected $db_password;
  protected $db;

  # {{{ Constructor
  function __construct($name) {
    $GLOBALS[$name] = array();
    $this->username = $name;
    $this->db = new $this->db_classname;
    $this->db->query(sprintf("select * from uservar where username = '%s'", $this->username));
    $this->db->next_record();
    $frozen = $this->db->f("variables");
    $var_array = unserialize($frozen);
    if (is_array($var_array)) {
      foreach ($var_array as $key => $value) {
        $GLOBALS[$this->username][$key] = $value;
        global $$key;
        $$key = $value;
      }
    }
  }

  # }}}
  # {{{ fmplib_uservar::register()
  function register($thing) {
  	global $$thing;
    $GLOBALS[$this->username][$thing] = $$thing;
  }
  
  # }}}
  # {{{ fmplib_uservar::unregister()
  function unregister($thing) {
    unset($GLOBALS[$this->username][$thing]);
  }
  
  # }}}
  # {{{ fmplib_uservar::freeze()
  function freeze() {
    foreach ($GLOBALS[$this->username] as $key => $value) {
      global $$key;
      $GLOBALS[$this->username][$key] = $$key;
    }
    $frozen = serialize($GLOBALS[$this->username]);
    $this->db->query(sprintf("delete from uservar where username = '%s'", $this->username));
    $this->db->query(sprintf("insert into uservar set username = '%s', variables = '%s'", $this->username, addslashes($frozen)));
  }
  
  # }}}
  # {{{ fmplib_uservar::thaw()
  function thaw() {
    $this->db->query(sprintf("select * from uservar where username = '%s'", $this->username));
    $this->db->next_record();
    $frozen = stripslashes($this->db->f("variables"));
    $var_array = unserialize($frozen);
	if (isset($var_array)) {
    	foreach ($var_array as $key => $value) {
    	  $GLOBALS[$this->username][$key] = $value;
      	  global $$key;
      	  $$key = $value;
    	}
	}
  }
  # }}}
}
# }}}
?>