php call foreign function as internal method

Question

I wanna make a syntax like jquery in php, I wrote that class:

class events{

    public function auth($user, $pass, $callback){
        $status = 0;
        if($user and $pass){
            $status = 1;
        }
        call_user_func($callback, $status);
    }

    public function login(){
        echo "Welcome!";
    }

}

$events = new events;
$user = "u";
$pass = "p";

And that's Jquery like syntax:

/**
 * Jquery type callback function
 */
$events->auth($user, $pass, function($status){
    if($status){
        $this->login();
    }else{
        echo "Fail";
    }
});

Everything is OK except $this variable I used outer that class methods, I cannot use the callback function as a internal function for using $this into that function codes. Can I correct that error by changing something in my class ?

I know that but I'm looking for a way to use $this in foreign functions which are calling by that class methods. — mohammad falahat
– mohammad falahat, Commented Oct 8, 2014 at 10:10
Why not call $events->login() instead of trying $this->login() ? — Vic
– Vic, Commented Oct 8, 2014 at 10:14

user3942918 · Accepted Answer · 2014-10-08 10:46:49Z

4

You need to bind your anonymous function to the object with Closure::bind.

Example:

class events{

    public function auth($user, $pass, $callback){
        $status = 0;
        if($user and $pass){
            $status = 1;
        }
        call_user_func(Closure::bind($callback, $this), $status);
    }

    public function login(){
        echo "Welcome!";
    }

}

$events = new events;
$user = "u";
$pass = "p";

$events->auth($user, $pass, function($status){
    if($status){
        $this->login();
    }else{
        echo "Fail";
    }
});

Output:

Welcome!

Also note that it's not necessary to use call_user_func(), you can replace that line with something like this if you prefer:

$callback = $callback->bindTo($this);
$callback($status);

edited Oct 8, 2014 at 10:46

answered Oct 8, 2014 at 10:20

user3942918

26.5k13 gold badges57 silver badges68 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

mohammad falahat Over a year ago

can I use Closure::bind in auth function? for example: Closure::bind($callback($status));

Vic Over a year ago

Yes, but not like that, because you are actually calling the closure before creating the bound copy. You can do this: $callback = Closure::bind($callback, $this); $callback($status); @Paul: please correct me if I'm wrong.

mohammad falahat Over a year ago

very very thanks @PaulCrovella and others for your great answers.

Steve · Accepted Answer · 2014-10-08 10:15:27Z

1

You can pass the instance of the class to the callback:

<?php
class events{

    public function auth($user, $pass, $callback){
        $status = 0;
        if($user and $pass){
            $status = 1;
        }
        $callback($status, $this);
    }

    public function login(){
        echo "Welcome!";
    }

}

$events = new events;
$user = "u";
$pass = "p";


/**
 * Jquery type callback function
 */
$events->auth($user, $pass, function($status, $self){
    if($status){
        $self->login();
    }else{
        echo "Fail";
    }
});

answered Oct 8, 2014 at 10:15

Steve

20.5k5 gold badges47 silver badges71 bronze badges

1 Comment

Vic Over a year ago

Yeah, I would be interested in an explanation too. This should work just fine.

Vic · Accepted Answer · 2014-10-08 10:22:12Z

1

There's no way to "bind" closures to specific objects like in JavaScript. The $this keyword cannot therefore be used outside of a class. However, since $events is the instance which $this would reference, you can do this:

$events->auth($user, $pass, function($status){
    if($status){
        $events->login();
    }else{
        echo "Fail";
    }
});

Edit: Apparently I was wrong, there is a way to bind closures to specific instances. See Paul's answer.

edited Oct 8, 2014 at 10:22

answered Oct 8, 2014 at 10:16

Vic

12.5k3 gold badges29 silver badges35 bronze badges

Collectives™ on Stack Overflow

php call foreign function as internal method

3 Answers 3

Example:

Output:

3 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Example:

Output:

3 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related