doc-block メタプログラミング マジックでドメイン検証デコレータを使用します。しかし、これは実際にはライブラリ全体の仕事であり、間違いなく存在します。
フィドル
<?php
class FooDomain {
public static function is_not_empty($input) {
return !empty($input);
}
}
class Foo {
/**
* @domain FooDomain::is_not_empty my_string
*/
public function print_string($my_string) {
echo $my_string . PHP_EOL;
}
}
$foo = new DomainValidator(new Foo());
$foo->print_string('Hello, world!');
try {
$foo->print_string(''); // throws a DomainException
} catch (\DomainException $e) {
echo 'Could not print an empty string...' . PHP_EOL;
}
// ---
class DomainValidator {
const DOMAIN_TAG = '@domain';
private $object;
public function __construct($object) {
$this->object = $object;
}
public function __call($function, $arguments) {
if (!$this->verify_domain($function, $arguments)) {
throw new \DomainException('Bad domain!');
}
return call_user_func_array(
array($this->object, $function),
$arguments
);
}
public function __get($name) {
return $this->object->name;
}
public function __set($name, $value) {
$this->object->name = $value;
}
private function verify_domain($function, $arguments) {
// Get reference to method
$method = new \ReflectionMethod($this->object, $function);
$domains = $this->get_domains($method->getDocComment());
$arguments = $this->parse_arguments(
$method->getParameters(),
$arguments
);
foreach ($domains as $domain) {
if (!call_user_func(
$domain['name'],
$arguments[$domain['parameter']]
)) {
return false;
}
}
return true;
}
private function get_domains($doc_block) {
$lines = explode("\n", $doc_block);
$domains = array();
$domain_tag = DomainValidator::DOMAIN_TAG . ' ';
foreach ($lines as $line) {
$has_domain = stristr($line, $domain_tag) !== false;
if ($has_domain) {
$domain_info = explode($domain_tag, $line);
$domain_info = explode(' ', $domain_info[1]);
$domains[] = array(
'name' => $domain_info[0],
'parameter' => $domain_info[1],
);
}
}
return $domains;
}
private function parse_arguments($parameters, $values) {
$ret = array();
for ($i = 0, $size = sizeof($values); $i < $size; $i++) {
$ret[$parameters[$i]->name] = $values[$i];
}
return $ret;
}
}
出力:
Hello, world!
Could not print an empty string...