提取元描述的內容使用DOM文檔（）和XPath在PHP

Question

凌晨1時試圖提取元描述的內容，從網頁在搜索結果中&顯示。 但它像顯示它：

內容=「Lorem存有胡蘿蔔，改善生態環境茉莉花便利保留需求茉莉花質量當拉手光芒超級碗山瞬間。。 「

而只需要1：

Lorem存有胡蘿蔔，改善生態環境。保留茉莉方便的需要。茉莉花質量。當拉手光芒超級碗山瞬間。

任何猜測，有什麼錯在我的代碼？

CODE：

$doc = new DOMDocument(); 
    @$doc->loadHTMLFile($page_path); 
    $xpath = new DOMXPath($doc); 

    $body = $xpath->query('//meta[@name="description"]/@content'); 
    $page_title = @$doc->getElementsByTagName('title')->item(0)->textContent; 
    $page_title = $page_title ? $page_title : $page_path; 
    $page_body = html2text($doc->saveXml($body->item(0)));// this is meta-description, which i want 

    Functions : 

    function html2text($html) 
    { 
    $text = $html; 
    static $search = array(
    '@<script.+?</script>@usi', // Strip out javascript content 
    '@<style.+?</style>@usi', // Strip style content 
    '@<!--.+?-->@us',   // Strip multi-line comments including CDATA 
    '@</?[a-z].*?\>@usi',   // Strip out HTML tags 
); 
    $text = preg_replace($search, ' ', $text); 
    /* 
    * normalize common entities 
    */ 
    $text = normalizeEntities($text); 
    /* 
    * decode other entities 
    */ 
    $text = html_entity_decode($text, ENT_QUOTES, 'utf-8'); 
    /* 
    * normalize possibly repeated newlines, tabs, spaces to spaces 
    */ 
    $text = preg_replace('/\s+/u', ' ', $text); 
    $text = trim($text); 
    return $text; 
    } 


    /** 
    * Replace encoded and double encoded entities to equivalent unicode character 
    * @param string $text 
    * @return string - the same as $text but without encoded entries 
    * @access public 
    */ 
    function normalizeEntities($text) 
    { 
    static $find = array(); 
    static $repl = array(); 
    if (!count($find)) { 
    /* 
    * build $find and $replace from map one time 
    */ 
    $map = array(
    array('\'', 'apos', 39, 'x27'), // Apostrophe 
    array('\'', '‘', 'lsquo', 8216, 'x2018'), // Open single quote 
    array('\'', '’', 'rsquo', 8217, 'x2019'), // Close single quote 
    array('"', '「', 'ldquo', 8220, 'x201C'), // Open double quotes 
    array('"', '」', 'rdquo', 8221, 'x201D'), // Close double quotes 
    array('\'', '‚', 'sbquo', 8218, 'x201A'), // Single low-9 quote 
    array('"', '„', 'bdquo', 8222, 'x201E'), // Double low-9 quote 
    array('\'', '′', 'prime', 8242, 'x2032'), // Prime/minutes/feet 
    array('"', '″', 'Prime', 8243, 'x2033'), // Double prime/seconds/inches 
    array(' ', 'nbsp', 160, 'xA0'), // Non-breaking space 
    array('-', '‐', 8208, 'x2010'), // Hyphen 
    array('-', '–', 'ndash', 8211, 150, 'x2013'), // En dash 
    array('--', '—', 'mdash', 8212, 151, 'x2014'), // Em dash 
    array(' ', ' ', 'ensp', 8194, 'x2002'), // En space 
    array(' ', ' ', 'emsp', 8195, 'x2003'), // Em space 
    array(' ', ' ', 'thinsp', 8201, 'x2009'), // Thin space 
    array('*', '•', 'bull', 8226, 'x2022'), // Bullet 
    array('*', '‣', 8227, 'x2023'), // Triangular bullet 
    array('...', '…', 'hellip', 8230, 'x2026'), // Horizontal ellipsis 
    array('°', 'deg', 176, 'xB0'), // Degree 
    array('€', 'euro', 8364, 'x20AC'), // Euro 
    array('¥', 'yen', 165, 'xA5'), // Yen 
    array('£', 'pound', 163, 'xA3'), // British Pound 
    array('©', 'copy', 169, 'xA9'), // Copyright Sign 
    array('®', 'reg', 174, 'xAE'), // Registered Sign 
    array('™', 'trade', 8482, 'x2122') // TM Sign 
); 
    foreach ($map as $e) { 
    for ($i = 1; $i < count($e); ++$i) { 
    $code = $e[$i]; 
    if (is_int($code)) { 
    // numeric entity 
    $regex = "/&(amp;)?#0*$code;/"; 
    } elseif (preg_match('/^.$/u', $code)/* one unicode char*/) { 
    // single character 
    $regex = "/$code/u"; 
    } elseif (preg_match('/^x([0-9A-F]{2}){1,2}$/i', $code)) { 
    // hex entity 
    $regex = "/&(amp;)?#x0*" . substr($code, 1) . ";/i"; 
    } else { 
    // named entity 
    $regex = "/&(amp;)?$code;/"; 
    } 
    $find[] = $regex; 
    $repl[] = $e[0]; 
    } 
    } 
    } 
    return preg_replace($find, $repl, $text); 
    } 

Answer 1

您正在保存屬性節點作爲XML。不要！只要閱讀它的價值。

：屬性節點（DOMAttr）有一個返回的屬性值的屬性值。該屬性值是一個文本值。

$html = <<<'HTML' 
<meta name="description" content="Some description"> 
HTML; 

$document = new DOMDocument(); 
$document->loadHTML($html); 
$xpath = new DOMXPath($document); 

$description = $xpath->evaluate('//meta[@name="description"]/@content')->item(0); 
var_dump($description->value); 

輸出：

string(16) "Some description" 

但是，XPath可直接作爲字符串返回值。只是把結果（在XPath）。這隻有在DOMXpath::evaluate()工作。 DOMXpath::query()只能返回節點列表。

$description = $xpath->evaluate('string(//meta[@name="description"]/@content)'); 
var_dump($description); 

輸出：

string(16) "Some description" 

它將爲其他節點工作，太。如果你只是在其文本內容投元素節點（如body）將被退回，像©實體將得到解碼。

$html = <<<'HTML' 
<html> 
    <head> 
    <title>The Title</title> 
    <meta name="description" content="Some description"> 
    </head> 
    <body> 
    <p>Some content &amp; entities &copy;</p> 
    </body> 
</html> 
HTML; 

$document = new DOMDocument(); 
$document->loadHTML($html); 
$xpath = new DOMXPath($document); 

$title = $xpath->evaluate('string(//head/title)'); 
$description = $xpath->evaluate('string(//meta[@name="description"]/@content)'); 
$content = $xpath->evaluate('string(//body)'); 

var_dump($title, $description, $content); 

輸出：

string(9) "The Title" 
string(16) "Some description" 
string(36) " 
    Some content & entities © 
    "