为一个班级提供2个其他班级的访问权限？

Question

I have a login script which I found online which was written in php4 and have tried to modify it so that it is php5 complient.

I have 4 classes: user, db, form, mailer

below is a snippet of my user class

<?php
include("include/database.php");
include("include/mailer.php");
include("include/form.php");

include("constants.php");

class user
{
var $username;     //Username given on sign-up
var $firstname;
var $lastname;
var $userid;       //Random value generated on current login
var $userlevel;    //The level to which the user pertains
var $time;         //Time user was last active (page loaded)
var $logged_in;    //True if user is logged in, false otherwise
var $userinfo = array();  //The array holding all user info
var $url;          //The page url current being viewed
var $referrer;     //Last recorded site page viewed
var $num_active_users;   //Number of active users viewing site
var $num_active_guests;  //Number of active guests viewing site
var $num_members;        //Number of signed-up users

/**
    * Note: referrer should really only be considered the actual
    * page referrer in process.php, any other time it may be
    * inaccurate.
    */

public function __construct(db $db, Form $form)
{
    $this->database = $db;
    $this->form = $form;
    $this->time = time();
    $this->startSession();

    $this->num_members = -1;

    if(TRACK_VISITORS)
    {
        /* Calculate number of users at site */
        $this->calcNumActiveUsers();

        /* Calculate number of guests at site */
        $this->calcNumActiveGuests();
    }


}   
   /**
   * startSession - Performs all the actions necessary to 
   * initialize this session object. Tries to determine if the
   * the user has logged in already, and sets the variables 
   * accordingly. Also takes advantage of this page load to
   * update the active visitors tables.
   */
  function startSession()
  {
    session_start();   //Tell PHP to start the session

    /* Determine if user is logged in */
    $this->logged_in = $this->checkLogin();

    /**
    * Set guest value to users not logged in, and update
    * active guests table accordingly.
    */
    if(!$this->logged_in)
    {
        $this->username = $_SESSION['username'] = GUEST_NAME;
        $this->userlevel = GUEST_LEVEL;
        $this->addActiveGuest($_SERVER['REMOTE_ADDR'], $this->time);
    }
    /* Update users last active timestamp */
    else
    {
        $this->addActiveUser($this->username, $this->time);
    }

    /* Remove inactive visitors from database */
    $this->removeInactiveUsers();
    $this->removeInactiveGuests();

    /* Set referrer page */
    if(isset($_SESSION['url']))
    {
         $this->referrer = $_SESSION['url'];
    }
    else
    {
        $this->referrer = "/";
    }

    /* Set current url */
    $this->url = $_SESSION['url'] = $_SERVER['PHP_SELF'];
  }
}

and i invoke the database and form like so

$db = new db($config);
$user = new User($db);
$form = new Form;

but it is throwing an error

Catchable fatal error: Argument 2 passed to user::__construct() must be an instance of Form, none given, called in C:\wamp\www\ecornwall3\include\user.php on line 900 and defined in C:\wamp\www\ecornwall3\include\user.php on line 30

But I'm not sure why. If I remove the form $form from the construct function it works fine, but I need access to the form class

Answer 1

The why is easy. Your constructor says this:

public function __construct(db $db, Form $form)

That means you have to give it 2 things: something with class db and something with class Form .

You call this:

$user = new User($db);

That does not have the Form , and that is exactly what you error says. If you delete the Form from the constructor you don't expect it anymore, so the error isn't there, but you don't have the right functionality.

What you should do is add the paramter to the constructor-call:

    $user = new User($db, $form);

Answer 2

You are not supplying enough parameters to User::__construct() constructor. Take a look at declaration:

public function __construct(db $db, Form $form)

It requires (as declared) 2 arguments: an instance of db class and an instance of Form class.

Try this:

$db = new db($config);
$form = new Form;
$user = new User($db, $form);