反射 class 在 php 中是否有隐式方法 __toString()？

Question

我正在阅读https://www.amazon.com/PHP-MySQL-Web-Development-4th/dp/0672329166 .在 OOP 章节中，我实现了 page class（下面的代码），然后在另一个脚本中尝试通过 Reflection("Page") 创建一个实例，然后尝试 [=18] =] 那 class （通过隐式方法 __toString()，就像书中一样：

page.php:

<?php

class Page
{
    public $content;
    public function setContent(string $c)
    {
        $this->content = $c;
    }
    public $title = "Papaluz Corp";
    public function setTitle(string $t)
    {
        $this->title = $t;
    }
    public $keywords = " Papaluz Consulting, Three Letter Abbreviation,
    some of my best friends are search engines";
    public function setKeywords(string $k)
    {
        $this->keywords = $k;
    }
    public $buttons = [
        'Home' => 'home.php',
        'Contact' => 'contact.php',
        'Services' => 'services.php',
        'About' => 'about.php'
    ];
    public function setButtons(array $b)
    {
        $this->buttons = $b;
    }

    public function display()
    {
        echo "<html>\n<head>\n";
        $this->displayTitle();
        $this->displayKeywords();
        $this->displayStyles();
        echo "</head>\n<body>\n";
        $this->displayHeader();
        $this->displayMenu($this->buttons);
        echo $this->content;
        $this->displayFooter();
        echo "</body>\n</html>\n";
    }
    public function displayTitle()
    {
        echo '<title>' . $this->title . '</title>';
    }
    public function displayKeywords()
    {
        echo '<meta name="keywords" content="' . $this->keywords . '"/>';
    }
    public function displayStyles()
    {
?>
        <link href="/2/default/style.css" rel="stylesheet">
    <?php
    }
    public function displayHeader()
    {
    ?>
        <header>
            <img src='/data/img/pap_white.png' width="130" height="130">
            <h1>Papaluz Consulting</h1>
        </header>
    <?php
    }
    public function displayMenu(array $buttons)
    {
        echo '<nav>';
        foreach ($buttons as $name => $url) {
            $this->displayButton($name, $url, !$this->isUrlCurrentPage($url));
        }
        echo "</nav>\n";
    }
    public function displayFooter()
    {
    ?>
        <footer>
            <p>&copy; Papluz consulting Corp.<br>
                please see our<a href='legal.php'>legal information page</a>.
            </p>
        </footer>
        <?php
    }

    public function isUrlCurrentPage($url)
    {
        if (strpos($_SERVER['PHP_SELF'], $url) === false) {
            return false;
        } else {
            return true;
        }
    }
    public function displayButton($name, $url, $active = true)
    {
        if ($active) {
        ?>
            <div class="menuitem">
                <a href="<?= $url ?>">
                    <img src='/data/img/arrow_white.svg' width="20" height="20">
                    <span class='menutext'><?= $name ?></span>
                </a>
            </div>
        <?php
        } else {
        ?>
            <div class="menuitem">
                <!-- <img src='/data/img/arrow_white.svg'> -->
                <span class='menutext'><?= $name ?></span>
            </div>
<?php
        }
    }
}

class 本身并不重要，但是从 Reflection class 推断它的尝试是：

foo.php:

<?php
require_once('page.php');
$class = new Reflection('Page');
echo '<pre>'.$class.'</pre>';

给出错误：

Recoverable fatal error: Object of class Reflection could not be converted to string in /var/www/html/2/foo.php on line 5

所以错误说 Reflection class 没有方法 __toString()，但因为它在书中作为示例，我认为它应该。那么如何回显变量 $class，它是通过 Reflaction class?

推断出的 Page class

Answer 1

这本书和例子已经很过时了，2020年不建议这样开发。代码充满了XSS安全问题和糟糕的代码风格。不管怎样，你可以在这里试试这个来反映 class:

<?php

// ...

$reflector = new ReflectionClass('Page');

$properties = $reflector->getProperties();

foreach($properties as $property)
{
    echo $property->getName() . "\n";
}

反射 class 在 php 中是否有隐式方法 __toString()？

Does reflection class have implicit method __toString() in php?

php

class

oop

tostring