使用SimpleXML訪問XML中的名稱空間冒號節點PHP

Question

這與我發佈的問題類似，但我已經擴大了，因爲這已經可以解決。

我正在嘗試從此rss提要訪問評級和viewCount。現在，這些命名空間與yt：和gd： - 不同，但命名空間引用是來自YouTube的Feed的404，因此它似乎失敗了。請提供任何幫助嗎？

我想使用： -

$ytFeed->children('http://gdata.youtube.com/schemas/2007')->statistics->attributes('viewCount')); 

但它失敗......它不喜歡的工作，通常，比如我可以訪問媒體：與

$ytFeed->children('http://search.yahoo.com/mrss/')->group->category); 

這是原來的RSS，請看這些節點的底部： -

<?xml version='1.0' encoding='UTF-8'?> 
<entry xmlns='http://www.w3.org/2005/Atom' xmlns:media='http://search.yahoo.com/mrss/' xmlns:gd='http://schemas.google.com/g/2005' xmlns:yt='http://gdata.youtube.com/schemas/2007'> 
    <id>http://gdata.youtube.com/feeds/api/videos/tDJFDsZFw2E</id> 
    <published>2009-03-02T07:02:49.000Z</published> 
    <updated>2011-07-19T06:57:29.000Z</updated> 
    <category scheme='http://schemas.google.com/g/2005#kind' term='http://gdata.youtube.com/schemas/2007#video' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/categories.cat' term='Music' label='Music' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='Other Lives' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='Jesse Tabish' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='Jenny Hsu' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='Jupiter Hotel' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='Portland' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='music' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='band' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='interview' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='mf magazine' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='fashion' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='hotel room' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='doug fir lounge' /> 
    <category scheme='http://gdata.youtube.com/schemas/2007/keywords.cat' term='erik schultz' /> 
    <title type='text'>Other Lives</title> 
    <content type='text'>We sat down with Jesse Tabish and Jenny Hsu from Other Lives at the Jupiter Hotel in Portland, OR. We love these guys. Check them out at myspace.com/otherlivesVisit mf magazine at musicfashionmagazine.com or myspace.com/musicfashion</content> 
    <link rel='alternate' type='text/html' href='http://www.youtube.com/watch?v=tDJFDsZFw2E&amp;feature=youtube_gdata' /> 
    <link rel='http://gdata.youtube.com/schemas/2007#video.responses' type='application/atom+xml' href='http://gdata.youtube.com/feeds/api/videos/tDJFDsZFw2E/responses' /> 
    <link rel='http://gdata.youtube.com/schemas/2007#video.related' type='application/atom+xml' href='http://gdata.youtube.com/feeds/api/videos/tDJFDsZFw2E/related' /> 
    <link rel='self' type='application/atom+xml' href='http://gdata.youtube.com/feeds/api/videos/tDJFDsZFw2E' /> 
    <author> 
     <name>mfmagazine</name> 
     <uri>http://gdata.youtube.com/feeds/api/users/mfmagazine</uri> 
     </author> 
    <gd:comments> 
     <gd:feedLink href='http://gdata.youtube.com/feeds/api/videos/tDJFDsZFw2E/comments' countHint='16' /> 
     </gd:comments> 
    <media:group> 
     <media:category label='Music' scheme='http://gdata.youtube.com/schemas/2007/categories.cat'>Music</media:category> 
     <media:content url='http://www.youtube.com/v/tDJFDsZFw2E?f=videos&amp;app=youtube_gdata' type='application/x-shockwave-flash' medium='video' isDefault='true' expression='full' duration='600' yt:format='5' /> 
     <media:content url='rtsp://v3.cache3.c.youtube.com/CiILENy73wIaGQlhw0XGDkUytBMYDSANFEgGUgZ2aWRlb3MM/0/0/0/video.3gp' type='video/3gpp' medium='video' expression='full' duration='600' yt:format='1' /> 
     <media:content url='rtsp://v6.cache3.c.youtube.com/CiILENy73wIaGQlhw0XGDkUytBMYESARFEgGUgZ2aWRlb3MM/0/0/0/video.3gp' type='video/3gpp' medium='video' expression='full' duration='600' yt:format='6' /> 
     <media:description type='plain'>We sat down with Jesse Tabish and Jenny Hsu from Other Lives at the Jupiter Hotel in Portland, OR. We love these guys. Check them out at myspace.com/otherlivesVisit mf magazine at musicfashionmagazine.com or myspace.com/musicfashion</media:description> 
     <media:keywords>Other Lives, Jesse Tabish, Jenny Hsu, Jupiter Hotel, Portland, music, band, interview, mf magazine, fashion, hotel room, doug fir lounge, erik schultz</media:keywords> 
     <media:player url='http://www.youtube.com/watch?v=tDJFDsZFw2E&amp;feature=youtube_gdata_player' /> 
     <media:thumbnail url='http://i.ytimg.com/vi/tDJFDsZFw2E/0.jpg' height='240' width='320' time='00:05:00' /> 
     <media:thumbnail url='http://i.ytimg.com/vi/tDJFDsZFw2E/1.jpg' height='90' width='120' time='00:02:30' /> 
     <media:thumbnail url='http://i.ytimg.com/vi/tDJFDsZFw2E/2.jpg' height='90' width='120' time='00:05:00' /> 
     <media:thumbnail url='http://i.ytimg.com/vi/tDJFDsZFw2E/3.jpg' height='90' width='120' time='00:07:30' /> 
     <media:title type='plain'>Other Lives</media:title> 
     <yt:duration seconds='600' /> 
     </media:group> 
    <gd:rating average='5.0' max='5' min='1' numRaters='17' rel='http://schemas.google.com/g/2005#overall' /> 
    <yt:statistics favoriteCount='10' viewCount='3572' /> 
    </entry> 

Answer 1

使用DomDocument和DomXpath：

error_reporting(E_ALL^E_STRICT); 
ini_set('display_errors', 'on'); 

$dom = new DomDocument; 
$dom->load('data.xml'); 

$xpath = new DomXpath($dom); 
$xpath->registerNamespace('atom', 'http://www.w3.org/2005/Atom'); 
$xpath->registerNamespace('media', 'http://search.yahoo.com/mrss/'); 
$xpath->registerNamespace('gd', 'http://schemas.google.com/g/2005'); 
$xpath->registerNamespace('yt', 'http://gdata.youtube.com/schemas/2007'); 

$favoriteCountAttr = $xpath->query('/atom:entry/yt:statistics/@favoriteCount')->item(0); 
if ($favoriteCountAttr instanceof DomAttr) { 
    echo $favoriteCountAttr->nodeValue; // output: 10 
} 

Answer 2

在調用子函數時簡單傳遞名稱空間參數

$nodes = $xml->children('gd', true); 

參見手冊：http://www.php.net/manual/en/simplexmlelement.children.php

Answer 3

好了，第一個問題是，你是濫用attributes方法：

$simpleXML->statistics->attributes('viewCount')); 

在

上面（從你的例子中解釋）你傳入你想要的屬性名稱，這不是attributes接受的參數。相反，上述內容將返回statistics元素的所有屬性，其中屬性本身的名稱空間爲viewCount，因爲該方法需要第一個參數（如果設置了）作爲屬性的名稱空間。

，如果你不是訪問的屬性作爲元素的數組，像這樣您的代碼將工作：

$ytFeed->children('http://gdata.youtube.com/schemas/2007')->statistics['viewCount']; 

如果你想避免每次使用完整的命名空間URI和children方法，你可以通過使用getNamespaces方法映射所有名稱空間來一個陣列，並且然後經由children方法映射與該命名空間孩子一個對象，如簡化：

$namespaces = $ytFeed->getNameSpaces(true); 
$yt = $ytFeed->children($namespaces['yt']); 
$yt->statistics['viewCount']; 

// Access all media: namespaced group elements like in your "working" example: 
$media = $ytFeed->children($namespaces['media']); 
$media->group->category; 

我意識到這是在2葉一個答案被接受了，但接受的答案實際上只是一個更好的文檔和更直觀的選擇，但並沒有告訴其他人發現這個問題的實際方法來實現SimpleXML，最終只需要一個額外的兩行代碼添加到DOMDocument的6到8個額外的行和一個不同的擴展中，這可能會誤導未來的讀者認爲它不能用SimpleXML完成。它可以，而且很容易，不是很明顯。