Extract method call from string - php

Question

How to extract method name and argument from a string code?
Example :
$obj->MethodA($obj->MethodB(param1,$obj->MethodX()))
I tried using this regex but not work
preg_match_all('/\$obj->(\w+)\(((\w|,| )*)\)/', $string, $matches)
The aim is to extract all the method calls as well as their arguments, so the matches should match
$obj->MethodA($obj->MethodB(param1, $obj->MethodX()))
$obj->MethodB(param1,$obj->MethodX())
$obj->MethodX()
Some people might say using regex is not ideal. Is there any alternative?

Answer 1

I would recommend using something that understands PHP's syntax. For example this library - https://github.com/nikic/PHP-Parser
Regex would probably get unwieldy pretty fast.
Quick example using the mentioned PHP-Parser.
use PhpParser\Node\Expr\CallLike;
use PhpParser\NodeFinder;
use PhpParser\ParserFactory;
use PhpParser\PrettyPrinter\Standard;
$php = '<?php $obj->MethodA($obj->MethodB("test",$obj->MethodX()));';
$parserFactory = new ParserFactory();
$parser = $parserFactory->create(ParserFactory::PREFER_PHP7);
$statements = $parser->parse($php);
$finder = new NodeFinder();
// Or if you only want method calls, we could also find instances of MethodCall
$calls = $finder->findInstanceOf($statements, CallLike::class);
$printer = new Standard();
foreach ($calls as $call) {
echo $printer->prettyPrintExpr($call) , "\n";
}
// Output
//$obj->MethodA($obj->MethodB("test", $obj->MethodX()))
//$obj->MethodB("test", $obj->MethodX())
//$obj->MethodX()