php - PHP 等价于 jQuery addClass

Question

您将如何将一个名为的类添加newClass到像 php或使用 php的开始标签中？<a class='abc'><p style=display:block>

Answer 1

正则表达式示例：

<?php
function addClass($htmlString = '', $newClass) {
    $pattern = '/class="([^"]*)"/';

    // class attribute set
    if (preg_match($pattern, $htmlString, $matches)) {
        $definedClasses = explode(' ', $matches[1]);
        if (!in_array($newClass, $definedClasses)) {
            $definedClasses[] = $newClass;
            $htmlString = str_replace($matches[0], sprintf('class="%s"', implode(' ', $definedClasses)), $htmlString);
        }
    }

    // class attribute not set
    else {
        $htmlString = preg_replace('/(\<.+\s)/', sprintf('$1class="%s" ', $newClass), $htmlString);
    }

    return $htmlString;
}

echo addClass('<a class="abc">', 'newClass');
echo addClass('<p style=display:block>', 'newClass');

使用http://php.net/manual/en/book.dom.php示例

<?php
function addClass($node = null, $className) {
    $result = false;

    if (is_string($node)) {
        $dom = DOMDocument::loadXml($node);
        if ($dom instanceof DOMDocument) {
            $definedClasses = explode(' ', $dom->documentElement->getAttribute('class'));
            if (!in_array($className, $definedClasses)) {
                $dom->documentElement->setAttribute(
                    'class', $dom->documentElement->getAttribute('class') . ' ' . $className
                );
            }

            $result = $dom->saveXml($dom->documentElement, true);
        }
    }
    elseif ($node instanceof DOMElement) {
        // this code repetition, could of course be avoided using some more sophisticated structures 
        $definedClasses = explode(' ', $node->getAttribute('class'));
        if (!in_array($className, $definedClasses)) {
            $node->setAttribute('class', $node->getAttribute('class') . ' ' . $className);
        }

        $result = $node;
    }

    return $result;
}

// using a string as input
echo addClass('<a class="abc"></a>', 'newClass');

// using a DOMElement as input
$dom = DOMDocument::loadHtml('<div><a id="something"></a></div>');
$xpath = new DOMXPath($dom);

$node = $xpath->query('//*[@id="something"]')->item(0);
if ($node instanceof DOMElement) {
    addClass($node, 'newClass');
    echo $dom->saveXml($node, true);
}

我故意不使用loadHTML（在函数内部）以防止不得不深入到自动生成的 html 结构中以找到实际给定的$htmlString. 这当然意味着$htmlString必须是格式良好的。

Answer 2

Nette Framework中的Html 类在PHP 中生成 HTML 标记非常出色。