Call function from class by string.

[Chris92]

Hi I'm setting up my own framework for a project. I was coming to the point of completion and thought up of a new idea.

 

Is it possible to call a function like this from a class:

class myClass {

    function func($param)
    {
        echo "Hello world". $param;
    }

}

$class = 'myClass';
$func = "func(' It\'s time to partey!')";

$$class = new $class;
$$class->$func;

 

Thanks for any help!

[trq]

call_user_func.

[Chris92]

I'm not sure if that's the one I'm looking for. If I'm using it correctly:

 

class myClass {

    function func($param)
    {
        echo "Hello world". $param;
    }

}

$class = 'myClass';
$func = "func";
$str = ' It\'s time to partey!';

$$class = new $class;
call_user_func($$class->$func, $str );

 

throws this error:

 

Notice: Undefined property: myClass::$func

 

Making me guess that it's trying to call it as a variable rather than function.

 

Ignore that!

 

I've gotten to this error now :

Fatal error: Using $this when not in object context

[ManiacDan]

No you haven't, there's no $this in that code snippet.  The error you're getting is related to you not having the proper callback format as the first argument to call_user_func.

 

That being said...what's with the variable variables?  Why are you doing it like this?  It's confusing and sloppy and will make maintaining this code hell.

 

-Dan

[Chris92]

Yeah, I just wrote that code for a quick example. What I'm doing is writing a framework which allows dynamic templates to call functions from different plug-ins

 

example:

<div id="twitter">
    {PLUGIN_twitter_tweets(5)}
</div>

 

This is then parsed by my template system, and then gets the plug-in required (in this case twitter), and call the function "tweets" and pass 5 as a parameter.

 

Here's something like what I've made

class template {

// shit load of functions, constants blah blah

// this function gets called after a few tests
// it replaces all the {PLUGIN_*} tags it can.
function plugin()
{
	preg_match_all( '~{PLUGIN_[^}]+}~', $this->html, $array );
	foreach( $array[0] as $value )
	{
		$value = str_replace( array('{', 'PLUGIN_', '}'), '', $value );
		$plugin = explode( '_', $value, 2 );

		$this->load->plugin($plugin[0]); // loads the PHP class (once)

		$$plugin[0] = new $plugin[0];

		$str = call_user_func( array( $plugin[0], $plugin[1] ) ); // this is the bit where I'm stuck

		$this->html = str_replace( '{PLUGIN_' . $value . '}',  $str, $this->html );
	}
}
}

 

Twitter class

class twitter {

// another load of functions and constants are here...

function tweets($limit, $image=true, $links=true, $name=true, $sname=true)
{
	$object = $this->getTweets($limit);
	$html = "";
	foreach( $object as $tweet )
	{
		$html .= "<div class=\"tweet\">\n".

					( ( $image === true ) ? "<a href=\"http://twitter.com/{$this->username}\" target=\"_blank\">
												<img src=\"{$tweet->user->profile_image_url}\" alt=\"{$tweet->user->name}\" />
											 </a>\n" : '' ).

					( ( $sname === true ) ? "<span class=\"screen-name\"><a href=\"http://twitter.com/{$this->username}\" target=\"_blank\">{$tweet->user->screen_name}</a></span>\n" : '' ).

					( ( $name === true ) ? "<span class=\"name\"><a href=\"http://twitter.com/{$this->username}\" target=\"_blank\">{$tweet->user->name}</a></span>\n" : '' ).

					"<p class=\"text\">" . ( ( $links === true ) ? $this->links($tweet->text) : $this->text ) . "</p>" .

					"<p class=\"time\">" . $this->time($tweet->created_at) . ".</p>" .
				"</div>\n";
	}
	return $html;
}

}

 

So as you can see it will requite that I can refer to children and ancestors.

[Chris92]

I made a nice solution, here's an example:

 

<?php

class twitter {

var $v = "Hi";

function tweets($i, $b)
{
	return $this->v . $i ."? ". $b;
}

}

$str = "twitter_tweets(5, true)";

$plugin = explode( "_", $str, 2 ); // array( [0] => twitter, [1] = tweets(5, true) )

$func = explode( "(", $plugin[1], 2 ); // array( [0] => tweets, [1] => 5, true) )

$args = substr( $func[1], 0, (strlen($func[1])-1) ); // 5, true
$args = explode( ",", $args ); // array( [0] => 5, [1] => true )

// trim whitespace in arguments
foreach( $args as $key => $val )
{
$args[$key] = trim($val);
}

$$plugin[0] = new $plugin[0]; // $twitter = new twitter

echo call_user_func_array( array( $$plugin[0] , $func[0] ), $args ); // $twitter->tweets(5,true)

?>