How to read comments of a class, function or method?

Question

I’ve seen some implementations in the Symfony and Laravel framework that allow you to define through comments routes in controller methods, or the Doctrine Models' Annotation definitions.

Sort of like this:

class Usuariosontroller

{
    /**
     * @Route('GET', 'usuarios')
    */
    public function getIndex()
    {

    }

}

How frameworks do to read this block of comments on top of the methods?

Answer 1

Class

Using the ReflectionClass to access the class, and thus get the value of the comment using the method getDocComment:

$reflection = new ReflectionClass('Usuariosontroller');
echo $reflection->getDocComment();

Example Ideone.

Method

Also using the ReflectionClass to access the class, now use the getMethod to access the method you want to obtain the information using the method getDocComment:

$reflection = new ReflectionClass('Usuariosontroller'); 
echo $reflection->getMethod('getIndex')->getDocComment();

Example Ideone.

Function

Use the ReflectionFunction to access the function, in sequence the getDocComment to access the comment:

$reflection = new ReflectionFunction('beber');
$reflection->getDocComment()    

Example Ideone.

Observing:

There are a few ways to comment, but the above methods only work if you use the comment whose token is T_DOC_COMMENT, that is, comments that obey syntax: /** */, then comments using token T_COMMENT - syntax // or #, and /* */ - will be ignored.

Answer 2

You can also use token_get_all php native.

filing cabinet index php.

/**

    COMENTÁRIO

*/

function foo(){
    echo "foo";
}

Running...

$array = token_get_all(file_get_contents("index.php"));

foreach($array as $arr){
    if(isset($arr[0]) && ($arr[0] == T_DOC_COMMENT || $arr[0] == T_COMMENT)){
        print_r($arr[1]);
    }
}

exit:

/** COMMENTING */