[PHP] xpath提取网页数据内容

想要使用xpath来解析html内容, PHP自带两个对象

DOMDocumentDOMXpath,其中初始化 loadHtml一般都会报很多警告,但是并不影响使用,用@屏蔽错误。

    /**
     * 初始化DOMXpath对象
     *
     * @param [type]  $content  网页内容
     * @param [array] $pathinfo 匹配信息
     *
     * @return void
     */
    private function _createXpathObj($content, $patinfo)
    {
        // 如果没有xpath配置项,不初始化xpath
        if (!$this->_existsXpathParse($patinfo)) {
            return;
        }
        try {
            $dom = new DOMDocument();
            @$dom->loadHtml($content);
            $dom->normalize();
            $xpath = new DOMXpath($dom);
            $this->xpathObj = $xpath;
        } catch (Exception $e) {
            getService('logger')->warning('Parse html fail', ['content' => $content]);
        }
    }

其中 $nodeDOMElement 对象。

    /**
     * 获取Xpath解析值
     *
     * @param [type] $pat 匹配模式
     *
     * @return string
     */
    private function _getXpathField($pat)
    {
        $objs = $this->xpathObj->query($pat);
        if ($objs->length > 0) {
            $node = $objs->item(0);
            $outerHTML = $node->ownerDocument->saveHTML($node);
            return trim($outerHTML);
            # 作为示例 输出innerhtml
            //$innerHTML = '';
            //foreach ($node->childNodes as $childNode){
            //     $innerHTML .= $childNode->ownerDocument->saveHTML($childNode);
            //}
            //return $innerHTML; 
            # 作为示例 输出文本不含标签
            //return $node->textContent; //$node->nodeValue;
        }
        return '';
    }

示例

<?php
        $dom = new DOMDocument('1.0','UTF-8');
        $dom->loadHTML('<html><body><div><p>p1</p><p>p2</p></div></body></html>');        
        $node = $dom->getElementsByTagName('div')->item(0);        
        $outerHTML = $node->ownerDocument->saveHTML($node);        
        $innerHTML = '';
        foreach ($node->childNodes as $childNode){
                $innerHTML .= $childNode->ownerDocument->saveHTML($childNode);
        }
        echo '<h2>outerHTML: </h2>';
        echo htmlspecialchars($outerHTML);
        echo '<h2>innerHTML: </h2>';
        echo htmlspecialchars($innerHTML);        
?>




原文地址:https://www.cnblogs.com/wangluochong/p/13222665.html