在laravel下使用php-parser实现aop
composer require nikic/php-parser
Test.php
<?php
/**
* Created by PhpStorm.
* User: CSH
* Date: 2019/4/4
* Time: 11:26
*/
namespace app;
/**
* 为该类创建代理，并植入切面 埋点
* 使用parser生成对应的语法树，然后主动修改方法体内的逻辑
*
* Class Test
* @package app
*/
class Test
{
// do something before
// do something
// do something after
public function show()
{
return 'Hello World';
}
public function say()
{
return 'I Can Fly';
}
}
ProxyVisitor.php
<?php
/**
* Created by PhpStorm.
* User: CSH
* Date: 2019/4/4
* Time: 11:16
*/
namespace App\Aop;
use PhpParser\Node;
use PhpParser\Node\Expr\Closure;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Name;
use PhpParser\Node\Param;
use PhpParser\Node\Scalar\String_;
use PhpParser\Node\Stmt\Class_;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Return_;
use PhpParser\Node\Stmt\TraitUse;
use PhpParser\NodeFinder;
use PhpParser\NodeVisitorAbstract;
/**
* PHP Parser在Aop编程中的使用
*
* 流程：
* 1、当我们拿到节点是类时，我们重置这个类，让新建的类继承这个类。
* 2、当我们拿到的节点是类方法时，我们使用proxyCall来重写方法。
* 3、当遍历完成之后，给类加上我们定义好的AopTrait。
*
* NodeVisitor接口调用顺序：beforeTraverse -> enterNode -> leaveNode -> afterTraverse
*
* Class ProxyVisitor
* @package App\Aop
*/
class ProxyVisitor extends NodeVisitorAbstract
{
protected $className;
protected $proxyId;
public function __construct($className, $proxyId)
{
$this->className = $className;
$this->proxyId = $proxyId;
}
public function getProxyClassName()
{
return \basename(str_replace('\', '/', $this->className)).'_'.$this->proxyId;
}
public function getClassName()
{
return '\'.$this->className.'_'.$this->proxyId;
}
/**
* @return \PhpParser\Node\Stmt\TraitUse
*/
private function getAopTraitUseNode(): TraitUse
{
// Use AopTrait trait use node
return new TraitUse([new Name('\App\Aop\AopTrait')]);
}
/**
* Called when leaving a node
* 把类方法里的逻辑重置掉
*
* @param Node $node
* @return int|null|Node|Node[]|Class_|ClassMethod
*/
public function leaveNode(Node $node)
{
// Proxy Class
if ($node instanceof Class_) {
// Create proxy class base on parent class
return new Class_($this->getProxyClassName(), [
'flags' => $node->flags,
'stmts' => $node->stmts,
'extends' => new Name('\'.$this->className),
]);
}
// Rewrite public and protected methods, without static methods
if ($node instanceof ClassMethod && !$node->isStatic() && ($node->isPublic() || $node->isProtected())) {
$methodName = $node->name->toString();
// Rebuild closure uses, only variable
$uses = [];
foreach ($node->params as $key => $param) {
if ($param instanceof Param) {
$uses[$key] = new Param($param->var, null, null, true);
}
}
$params = [
// Add method to an closure
new Closure([
'static' => $node->isStatic(),
'uses' => $uses,
'stmts' => $node->stmts,
]),
new String_($methodName),
new FuncCall(new Name('func_get_args')),
];
$stmts = [
new Return_(new MethodCall(new Variable('this'), '__proxyCall', $params))
];
$returnType = $node->getReturnType();
if ($returnType instanceof Name && $returnType->toString() === 'self') {
$returnType = new Name('\'.$this->className);
}
return new ClassMethod($methodName, [
'flags' => $node->flags,
'byRef' => $node->byRef,
'params' => $node->params,
'returnType' => $returnType,
'stmts' => $stmts,
]);
}
}
/**
* Called once after traversal
* 把AopTrait扔到类里
*
* @param array $nodes
* @return array|null|Node[]
*/
public function afterTraverse(array $nodes)
{
$addEnhancementMethods = true;
$nodeFinder = new NodeFinder();
$nodeFinder->find($nodes, function (Node $node) use (&$addEnhancementMethods) {
if ($node instanceof TraitUse) {
foreach ($node->traits as $trait) {
// Did AopTrait trait use ?
if ($trait instanceof Name && $trait->toString() === '\App\Aop\AopTrait') {
$addEnhancementMethods = false;
break;
}
}
}
});
// Find Class Node and then Add Aop Enhancement Methods nodes and getOriginalClassName() method
$classNode = $nodeFinder->findFirstInstanceOf($nodes, Class_::class);
$addEnhancementMethods && array_unshift($classNode->stmts, $this->getAopTraitUseNode());
return $nodes;
}
}
/**
* 切面
*
* Trait AopTrait
* @package App\Aop
*/
trait AopTrait
{
/**
* AOP proxy call method
*
* @param \Closure $closure
* @param string $method
* @param array $params
* @return mixed|null
* @throws \Throwable
*/
public function __proxyCall(\Closure $closure, string $method, array $params)
{
$res = $closure(...$params);
if (is_string($res)) {
$res .= ' !!!';
}
return $res;
}
}
AopController.php
<?php
namespace App\Http\Controllers;
use PhpParser\ParserFactory;
use PhpParser\NodeDumper;
use PhpParser\NodeTraverser;
use App\Aop\ProxyVisitor;
use PhpParser\PrettyPrinter\Standard;
class AopController extends Controller
{
public function index()
{
$parser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7);
$ast = $parser->parse(file_get_contents(base_path().'/app/Test.php'));
// 把parser代码后的语法树(对象)转为字符串形式
// $dumper = new NodeDumper();
// dd($dumper->dump($ast));
$className = 'App\Test';
$proxyId = uniqid();
$visitor = new ProxyVisitor($className, $proxyId);
$traverser = new NodeTraverser();
$traverser->addVisitor($visitor);
// 使用已注册的访问者遍历节点数组,返回遍历节点数组
$proxyAst = $traverser->traverse($ast);
if (!$proxyAst) {
throw new \Exception(sprintf('Class %s AST optimize failure', $className));
}
$printer = new Standard();
// 打印一个节点数组
$proxyCode = $printer->prettyPrint($proxyAst);
// dd($proxyCode);
eval($proxyCode);
$class = $visitor->getClassName();
$bean = new $class();
echo $bean->show();
}
}
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