Question

With Regular Expressions I’m trying to remove all the methods/functions from the following code. Leaving the “global scope” alone. However, I can’t manage to make it match for all the inner content of a method.

<?php
$mother = new Mother();
class Hello
{
    public function FunctionName($value="username",)
    {

    }
    public function ododeqwdo($value='')
    {
        # code...
    }
    public function ofdoeqdoq($value='')
    {
    if(isset($mother)) {
        echo $lol;
    }
    if(lol(9)) {
       echo 'lol';
    }
    }
}
function user()
{
    if(isset($mother)) {
        echo $lol;
    }
    if(lol(9)) {
       echo 'lol';
    }
}
    $mother->global();
function asodaosdo() {

}

The current Regular Expression I have is: (?:(public|protected|private|static)\s+)?function\s+\w+\(.*?\)\s+{.*?} However, it won’t select a method that has brackets inside, like function user().

If someone could point me in the right direction.

Answer 1

You can’t do this properly with regex. You need to write a parser that can properly parse comments, string literals and nested brackets.

Regex cannot cope with these cases:

class Hello
{
  function foo()
  {
    echo '} <- that is not the closing bracket!';
    // and this: } bracket isn't the closing bracket either!
    /*
    } and that one isn't as well...
    */
  }
}

EDIT

Here’s a little demo of how to use the tokenizer function mentioned by XUE Can:

$source = <<<BLOCK
<?php

\$mother = new Mother("this function isNotAFunction(\$x=0) {} foo bar");

class Hello
{
    \$foo = 666;

    public function FunctionName(\$value="username",)
    {

    }
    private \$bar;
    private function ododeqwdo(\$value='')
    {
        # code...
    }
    protected function ofdoeqdoq    (\$value='')
    {
        if(isset(\$mother)) {
            echo \$lol . 'function() {';
        }
        if(lol(9)) {
           echo 'lol';
        }
    }
}

function user()
{
    if(isset(\$mother)) {
        echo \$lol;
    }
    /* comment inside */
    if(lol(9)) {
       echo 'lol';
    }
}
/* comment to preserve function noFunction(){} */
\$mother->global();

function asodaosdo() {

}

?>
BLOCK;

if (!defined('T_ML_COMMENT')) {
   define('T_ML_COMMENT', T_COMMENT);
} 
else {
   define('T_DOC_COMMENT', T_ML_COMMENT);
}

// Tokenize the source
$tokens = token_get_all($source);

// Some flags and counters
$tFunction = false;
$functionBracketBalance = 0;
$buffer = '';

// Iterate over all tokens
foreach ($tokens as $token) {
    // Single-character tokens.
    if(is_string($token)) {
        if(!$tFunction) {
            echo $token;
        }
        if($tFunction && $token == '{') {
            // Increase the bracket-counter (not the class-brackets: `$tFunction` must be true!)
            $functionBracketBalance++;
        }
        if($tFunction && $token == '}') {
            // Decrease the bracket-counter (not the class-brackets: `$tFunction` must be true!)
            $functionBracketBalance--;
            if($functionBracketBalance == 0) {
                // If it's the closing bracket of the function, reset `$tFunction`
                $tFunction = false;
            }
        }
    } 
    // Tokens consisting of (possibly) more than one character.
    else {
        list($id, $text) = $token;
        switch ($id) {
            case T_PUBLIC:
            case T_PROTECTED:
            case T_PRIVATE: 
                // Don'timmediately echo 'public', 'protected' or 'private'
                // before we know if it's part of a variable or method.
                $buffer = "$text ";
                break; 
            case T_WHITESPACE:
                // Only display spaces if we're outside a function.
                if(!$tFunction) echo $text;
                break;
            case T_FUNCTION:
                // If we encounter the keyword 'function', flip the `tFunction` flag to 
                // true and reset the `buffer` 
                $tFunction = true;
                $buffer = '';
                break;
            default:
                // Echo all other tokens if we're not in a function and prepend a possible 
                // 'public', 'protected' or 'private' previously put in the `buffer`.
                if(!$tFunction) {
                    echo "$buffer$text";
                    $buffer = '';
                }
       }
   }
}

which will print:

<?php

$mother = new Mother("this function isNotAFunction($x=0) {} foo bar");

class Hello
{
    $foo = 666;


     private $bar;


}


/* comment to preserve function noFunction(){} */
$mother->global();



?>

which is the original source, only without functions.