ast-extraction.md

Extracting AST from reflections

Method and Function body AST

Given a ReflectionMethod or ReflectionFunction, you can extract the content (within curly braces) as an Abstract Syntax Tree, or as unparsed AST (i.e. as normal code). This allows you to grab the AST from a specific method with very few lines of code:

<?php

$classInfo = (new \Roave\BetterReflection\BetterReflection())
    ->classReflector()
    ->reflect(\Foo\Bar\MyClass::class);

// Retrieves the AST statements array *within* the method's curly braces
$ast = $classInfo->getMethod('foo')->getBodyAst();
$php = $classInfo->getMethod('foo')->getBodyCode();

Note on extracting code using getBodyCode()

The code returned by the getBodyCode() method is pretty-printed using the AST unparser in the PhpParser library. This means the actual code returned here may be laid out differently to the original function or method. See the code documentation for details on how to provide a custom printer to override the default behaviour.

Fetching AST representation of a class or function

It is possible to fetch an AST representation of a class or function using the getAst() method on a ReflectionClass and ReflectionFunction.

<?php

$classInfo = (new \Roave\BetterReflection\BetterReflection())
    ->classReflector()
    ->reflect(\Foo\Bar\MyClass::class);

// Retrieves AST nodes for the entire class (including the class definition)
$ast = $classInfo->getAst();

Note that the node returned will be the top level of the class, thus including the actual class definition itself.