check if abstract class exists

Question

I'm writing a class to check all my dependencies. One of those dependencies are inherited classes.

//File: A.php (For this example, file doesn't exist)
abstract class A{
}

//File: B.php
class B extends A{
}

//File: index.php
$files = scandir("/var/www");

foreach( $files as $class ) {
    // Whole script fails here because file A.php doesn't exist.
    // Need a graceful check to let the developer know a file is missing.
    if( !class_exists($class) ) return false;

    // Do other dependency checks.
}

I'm having trouble working out how to test if a parent class exists, Without the fatal error

Class 'A' not found

I have error handling for for my common classes. But for this test case, I need to be able to test for extended classes without knowing their name.

Answer 1

Using pomeh's suggestion, I've created a function to search for "class" and "extends" on the same line. It'll need some optimizing, but it works, so can work on that later.

function is_inherited($filePath) {
    $classFileArray = file($filePath, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

    foreach($classFileArray as $line) {
        if( strpos($line, "class") === false ) continue;
        if( strpos($line, "extends") === false ) continue;

        $extendName = explode('extends', $line);
        $extendName = explode( ' ', $extendName[1]);
        return $extendName[1];
    }
    return false;
}

The library suggested by hakre sounds interesting, but overkill I think when a single function will work fine.