AST + Better Reflection (PHP Benelux 2016 Unconference)
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The document presents a detailed discussion on 'Better Reflection' in PHP, exploring its benefits, usage, and the underlying Abstract Syntax Tree (AST) concept. It outlines how reflection works and showcases examples of manipulating method bodies and class reflections using Better Reflection. The presentation concludes with ongoing and future developments aimed at improving core reflection compatibility and performance enhancements.
![// In ReflectionClass :
public static function createFromName($className)
{
return ClassReflector::buildDefaultReflector()->reflect($className);
}
// In ClassReflector :
public static function buildDefaultReflector()
{
return new self(new AggregateSourceLocator([
new PhpInternalSourceLocator(),
new EvaledCodeSourceLocator(),
new AutoloadSourceLocator(),
]));
}](https://image.slidesharecdn.com/160129-astbrphpbeneluxuncon2016-160129165434/85/AST-Better-Reflection-PHP-Benelux-2016-Unconference-30-320.jpg)
![// Save the class and require it
$classCode = (new CodePrinter())->prettyPrint([$classInfo->getAst()]);
$tmpFile = tempnam(sys_get_temp_dir(), 'br-monkey-patching');
file_put_contents($tmpFile, '<?php ' . $classCode);
require_once($tmpFile);
unlink($tmpFile);](https://image.slidesharecdn.com/160129-astbrphpbeneluxuncon2016-160129165434/85/AST-Better-Reflection-PHP-Benelux-2016-Unconference-37-320.jpg)
AST + Better Reflection (PHP Benelux 2016 Unconference)
- 1. AST + Better Reflection James Titcumb PHP Benelux 2016 Unconference
- 2. James Titcumb www.jamestitcumb.com www.roave.com www.phphants.co.uk www.phpsouthcoast.co.uk @asgrim Who is this guy?
- 3. Reflection
- 5. © 1937 Disney’s Snow White - disneyscreencaps.com
- 7. ● Structure ● Metadata ● Values ● Type introspection ● Modification Reflection
- 8. How does it work?
- 9. GET_REFLECTION_OBJECT_PTR(ce); lc_name = zend_str_tolower_dup(name, name_len); if ((ce == zend_ce_closure && (name_len == sizeof(ZEND_INVOKE_FUNC_NAME)-1) && memcmp(lc_name, ZEND_INVOKE_FUNC_NAME, sizeof(ZEND_INVOKE_FUNC_NAME)-1) == 0) || zend_hash_str_exists(&ce->function_table, lc_name, name_len)) { efree(lc_name); RETURN_TRUE; } else { efree(lc_name); RETURN_FALSE; }
- 10. Okay. What now?
- 13. What?
- 14. Why?
- 15. How?
- 16. Magic of the AST
- 18. WTF is AST?
- 19. use PhpParserParserFactory; $parser = (new ParserFactory) ->create(ParserFactory::PREFER_PHP7); print_r($parser->parse( file_get_contents('ast-demo-src.php') ));
- 21. AST `-- Echo statement `-- String, value "Hello world"
- 22. <?php echo "Hello " . "world";
- 23. AST `-- Echo statement `-- Concat |-- Left | `-- String, value "Hello " `-- Right `-- String, value "world"
- 25. Benefits?
- 28. $reflection = new ReflectionClass( 'BetterReflectionTestFixtureExampleClass' ); $this->assertSame( 'ExampleClass', $reflection->getShortName() );
- 30. // In ReflectionClass : public static function createFromName($className) { return ClassReflector::buildDefaultReflector()->reflect($className); } // In ClassReflector : public static function buildDefaultReflector() { return new self(new AggregateSourceLocator([ new PhpInternalSourceLocator(), new EvaledCodeSourceLocator(), new AutoloadSourceLocator(), ])); }
- 31. AutoloadSourceLocator ReflectionClass::createFromName(new MyClass) replace stream wrapper disable error handling call “class_exists” restore stream wrapper restore error handling store attempted filename load DO NOT LOAD FILE! return stored filename Read file and parse AST!
- 32. (don’t try this at home kids!) Some voodoo...
- 34. class MyClass { public function foo() { return 5; } }
- 35. // Create the reflection first // ***BEFORE*** class is loaded $classInfo = ReflectionClass::createFromName('MyClass');
- 36. // Override the body...! $methodInfo = $classInfo->getMethod('foo'); $methodInfo->setBody(function () { return 4; });
- 37. // Save the class and require it $classCode = (new CodePrinter())->prettyPrint([$classInfo->getAst()]); $tmpFile = tempnam(sys_get_temp_dir(), 'br-monkey-patching'); file_put_contents($tmpFile, '<?php ' . $classCode); require_once($tmpFile); unlink($tmpFile);
- 38. // Now create an instance, and call the function... $c = new MyClass(); var_dump($c->foo()); // will be 4!!!
- 40. What’s in it for me?
- 41. The future...
- 42. ● DONE Currently: rewriting the internals ○ SourceLocators “might” return some code ?! ● DONE Returning AST/Code for method/fn Ideas/plans - DONE
- 43. ● WIP More compatibility core reflection ● WIP Reflect core fns with default params ○ This is not currently possible with core reflection ● WIP Modification & exporting ● WIP Reflecting on closures Ideas/plans - WIP
- 44. ● Adding a getColumn() function ● PHP 7 compatibility ● @inheritDoc traversal (to inherit type hints) ● Make it faster Ideas/plans
- 45. ¯_(ツ)_/¯
- 47. Any questions? :) https://joind.in/talk/9a5d8 James Titcumb @asgrim