php - Call a session inside a function with object oriented php

Question

I'm new to oop and some lines of my code are only approximate, to indicate what I want to achieve.

I want to create a session with php within a function within a class and call it in another function.

class My_beautiful_class
{
public function index()
    {
        $_SESSION['ciao'] = 'ciao';
        var_dump($_SESSION);
    }
public function anotherfunction()
    {
        $this->index();
        var_dump($_SESSION);
    }
}

I just want to understand a concept: in this way, my code will work but, on the other end, it will execute everything it will find in my function index, in my other function anotherfunction. So, if I call two variable with the same name, I could have a problem.

I guess that in theory, I could handle the problem in another way which is that I could create a variable call sessionone for example and send it some values in with my index function:

class My_beautiful_class
{

public sessionone = [];

public function index()
    {
        $_SESSION['ciao'] = 'ciao';
        $this->sessionone = $_SESSION['ciao'];

    }
public function anotherfunction()
    {
        $this->sessionone;
        var_dump($_SESSION);
    }
}

, but I was wondering if there any way to for example call only one variable that lives in one function with my first approach.

Something like: (My code is wrong on purpose, it is only to indicate what I want to achieve)

public function index()
        {
            $_SESSION['ciao'] = 'ciao';
        }
public function anotherfunction()
        {
           $this->index( $_SESSION['ciao'] );
        }
    }

标签： phpvariablessession

Answer 1

The $_SESSION variable are what is called a Superglobal in PHP: http://php.net/manual/en/language.variables.superglobals.php This gives them a few unique traits.

First, Superglobals are accessible anywhere in your application regardless of scope. Setting the value of a superglobal key in one function will make the value accessible anywhere else in your application that you want to reference it.

Say for example we want to make a class to manage our session. That class may look something like this.

class SessionManager 
{
    public function __construct()
    {
        session_start();   //We must start the session before using it.
    }

    //This will set a value in the session.
    public function setValue($key, $value)
    {
        $_SESSION[$key] = $value;
    }

    //This will return a value from the session
    public function getValue($key)
    {
        return $_SESSION[$key];
    }

    public function printValue($key)
    {
        print($_SESSION[$key]);
    }
}

Once we have a class to manage it a few things happen. We can use this new class to add info to the session and also to retrieve it.

Consider the following code:

$session = new SessionManager();
$session->setValue('Car', 'Honda');

echo $session->getValue('Car'); // This prints the word "Honda" to the screen.
echo $_SESSION['Car']; //This also prints the word "Honda" to the screen.
$session->printValue('Car'); //Again, "Honda" is printed to the screen.

Because of a session being a superglobal, once you set a value on the session it will be assessable anywhere in your application, either in or outside of the class itself.