如何使用命名空间解析 XML？答案

【问题标题】：How to parse XML with namespace?如何使用命名空间解析 XML？
【发布时间】：2015-07-18 12:20:37
【问题描述】：

这是我尝试使用 PHP simplexml_load_string() 函数类解析的 xml 文件，但它只打印 </description> 标记并且不返回其余 xml

XML 文件：

<?xml version="1.0" encoding="UTF-8"?>
<rss xmlns:dcterms="http://purl.org/dc/terms/" xmlns:dfpvideo="http://api.google.com/dfpvideo" xmlns:media="http://search.yahoo.com/mrss/" xmlns:ngc="http://xml.natgeotv.com/fields" xmlns:ngs="http://prod.ngs.org/ngs" xmlns:ngsDebug="http://prod.ngs.org/ngs-debug" xmlns:ngsTax="http://prod.ngs.org/taxonomy" xmlns:os="http://a9.com/-/spec/opensearch/1.1/" xmlns:pl="http://xml.theplatform.com/data/object" xmlns:pl1="http://access.auth.theplatform.com/data/Account/2388557369" xmlns:pl2="http://access.auth.theplatform.com/data/Account/2423130747" xmlns:pla="http://xml.theplatform.com/data/object/admin" xmlns:plfile="http://xml.theplatform.com/media/data/MediaFile" xmlns:pllist="http://xml.theplatform.com/data/list" xmlns:plmedia="http://xml.theplatform.com/media/data/Media" xmlns:plrelease="http://xml.theplatform.com/media/data/Release" xmlns:wpf="http://prod.ngs.org/wpf" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ytcp="http://www.youtube.com/schemas/cms/2.0" version="2.0">
   <channel>
      <title>NG Video</title>
      <link>http://feed.theplatform.com/f/ngs/dCCn2isYZ9N9</link>
      <description>NG Video</description>
      <os:startIndex>1</os:startIndex>
      <os:itemsPerPage>100</os:itemsPerPage>
      <pllist:entryCount>1</pllist:entryCount>
      <item>
         <pl:id>http://data.media.theplatform.com/media/data/Media/97681476000</pl:id>
         <guid isPermaLink="false">a4ad87f6-cbe4-4816-9580-b6679af0ea73</guid>
         <title>NG Live!: Sheikh of the Arctic</title>
         <description>&lt;p&gt;Having completed more solo trips to the Poles than anyone else on the planet, Børge Ousland is sometimes surprised by who he runs into crossing the vast Arctic tundra.&lt;/p&gt;</description>
         <author />
         <media:keywords />
         <media:restriction relationship="deny" type="country" />
         <media:content channels="2" samplingrate="44.1" bitrate="535.928" medium="video" duration="175.031" expression="full" fileSize="11725511" framerate="29.97" type="video/mp4" height="346" isDefault="true" url="http://link.theplatform.com/s/ngs/ekLOLGt3bemU?feed=NG%20Video" width="616">
            <media:hash algo="md5">0AF4AD25977BF50888075D3547F67173</media:hash>
            <pl:added>Sun, 22 Dec 2013 02:41:46 GMT</pl:added>
            <plfile:assetType>mpeg4</plfile:assetType>
         </media:content>
         <media:thumbnail expression="full" fileSize="79478" type="image/jpeg" height="556" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_990x556_177596483623.jpg" width="990">
            <media:hash algo="md5">60FFCE1C849440050CBCBD259EF2CE65</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:41 GMT</pl:added>
            <plfile:assetType>Poster</plfile:assetType>
            <plfile:assetType>MED</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="209762" type="image/jpeg" height="720" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720.jpg" width="1280">
            <media:hash algo="md5">08AC83096DC5F7E48A7CDE4BFA23A27A</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:30 GMT</pl:added>
            <plfile:assetType>Mezzanine Image</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="2962" type="image/jpeg" height="68" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_120x68_177597507564.jpg" width="120">
            <media:hash algo="md5">605D86F9A2B606D97A653576E6CE99D2</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:45 GMT</pl:added>
            <plfile:assetType>Thumbnail</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="23707" type="image/jpeg" height="270" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_480x270_177598019578.jpg" width="480">
            <media:hash algo="md5">73F78D0314E0CC15CDA5C36AAE4560AD</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:42 GMT</pl:added>
            <plfile:assetType>Poster</plfile:assetType>
            <plfile:assetType>X-SM</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="83905" type="image/jpeg" height="576" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_1024x576_177598019579.jpg" width="1024">
            <media:hash algo="md5">5C4B05CE487697A63F4FEC8B51009497</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:43 GMT</pl:added>
            <plfile:assetType>Poster</plfile:assetType>
            <plfile:assetType>LG</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="114846" type="image/jpeg" height="720" isDefault="false" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_1280x720_177598019580.jpg" width="1280">
            <media:hash algo="md5">31BFBD1020B2277B7E6FDD353973F263</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:43 GMT</pl:added>
            <plfile:assetType>Poster</plfile:assetType>
            <plfile:assetType>X-LG</plfile:assetType>
         </media:thumbnail>
         <media:thumbnail expression="full" fileSize="37132" type="image/jpeg" height="360" isDefault="true" url="http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_640x360_177598019582.jpg" width="640">
            <media:hash algo="md5">2654AFBE193785E29FF0533CF977A473</media:hash>
            <pl:added>Sun, 02 Mar 2014 05:26:44 GMT</pl:added>
            <plfile:assetType>Poster</plfile:assetType>
            <plfile:assetType>SM</plfile:assetType>
         </media:thumbnail>
         <pubDate>Sat, 21 Dec 2013 06:56:49 GMT</pubDate>
         <plmedia:defaultThumbnailUrl>http://pmdvod.nationalgeographic.com/NG_Video/997/323/67322_1_1280x720_640x360_177598019582.jpg</plmedia:defaultThumbnailUrl>
         <plmedia:provider />
         <pl1:youTubeInStreamStandard>true</pl1:youTubeInStreamStandard>
         <pl1:youTubeInStreamTrueView>true</pl1:youTubeInStreamTrueView>
         <pl1:youTubeInVideo>true</pl1:youTubeInVideo>
         <pl1:youTubePublic>false</pl1:youTubePublic>
         <ngs:clipTypeOld>none</ngs:clipTypeOld>
         <ngs:contentCreationDate>Mon, 13 May 2013 19:03:22 GMT</ngs:contentCreationDate>
         <ngs:network>NGS</ngs:network>
         <ngs:redirectToExternal>never</ngs:redirectToExternal>
         <ngs:requiresAuth>false</ngs:requiresAuth>
         <ngs:series>{"updated_datetime":null,"creation_datetime":null,"is_active":false,"name":"National Geographic Live","translated_names":[],"synonyms":[],"uuid":null,"notes":null,"objectType":"org.ngs.video.Show","groups":[],"url":null}</ngs:series>
         <ngs:seriesName>National Geographic Live</ngs:seriesName>
         <ngsTax:location>{"updated_datetime":"2014-04-03T19:09:42.570Z","is_active":true,"creation_datetime":"2013-11-28T20:27:32.077Z","parent":"http://taxonomy.nationalgeographic.com/api/v1/locations/eea9ad49-32fc-3a7c-bf15-cfeabdaa2fb7","geonames_uri":null,"url":"http://taxonomy.nationalgeographic.com/api/v1/locations/ff4e742f-46e6-3867-be8c-003a7af8f86c","dbpedia_uri":"http://dbpedia.org/page/Arctic","name":"Arctic","longitude":0.0,"hierarchy":"earth/arctic/","latitude":0.0,"uuid":"ff4e742f-46e6-3867-be8c-003a7af8f86c","notes":"","objectType":"org.ngs.taxonomy.GeoLocation","groups":["Place","region"],"english_name":null,"parentName":"Earth"}</ngsTax:location>
         <ngsTax:location>{"updated_datetime":"2014-05-28T20:43:43.719Z","is_active":true,"creation_datetime":"2013-11-28T20:01:26.936Z","synonyms":[null,null],"parent":"http://taxonomy.nationalgeographic.com/api/v1/locations/eea9ad49-32fc-3a7c-bf15-cfeabdaa2fb7","geonames_uri":"http://sws.geonames.org/6697173/","url":"http://taxonomy.nationalgeographic.com/api/v1/locations/d2ce52aa-c6ac-3a13-9f8c-59cb13ecb924","dbpedia_uri":null,"name":"Antarctica","translated_names":[null],"longitude":16.40626,"hierarchy":"earth/antarctica/","latitude":-78.15856,"uuid":"d2ce52aa-c6ac-3a13-9f8c-59cb13ecb924","notes":"","objectType":"org.ngs.taxonomy.GeoLocation","groups":["Place","continent"],"english_name":null,"parentName":"Earth"}</ngsTax:location>
         <ngsTax:organization>{"updated_datetime":"2014-05-02T15:37:25.776Z","creation_datetime":"2013-11-28T19:40:52.694Z","is_active":true,"name":"National Geographic Live","synonyms":[null],"uuid":"bae34d69-0601-342b-abe4-345c4c2486c4","notes":"","objectType":"org.ngs.taxonomy.Organization","english_name":null,"groups":["Organization"],"url":"http://taxonomy.nationalgeographic.com/api/v1/organizations/bae34d69-0601-342b-abe4-345c4c2486c4"}</ngsTax:organization>
         <ngsTax:slug>ousland-sheikh-bonus-nglive</ngsTax:slug>
         <ngsTax:subject>{"updated_datetime":"2014-06-04T15:56:21.047Z","definition":"","is_active":true,"creation_datetime":"2013-11-28T19:59:40.956Z","scope_note":"","synonyms":[null],"parent":"http://taxonomy.nationalgeographic.com/api/v1/subjects/83bf00d5-93bd-3cca-acc3-543652f06d52","url":"http://taxonomy.nationalgeographic.com/api/v1/subjects/58f9272e-f37b-3550-a228-a5ee119553ae","name":"Explorers","hierarchy":"exploration/explorers/","uuid":"58f9272e-f37b-3550-a228-a5ee119553ae","notes":"","objectType":"org.ngs.taxonomy.Subject","groups":["Subject"],"english_name":null,"parentName":"Exploration"}</ngsTax:subject>
         <ngsTax:subject>{"updated_datetime":"2014-01-29T14:56:08.338Z","definition":"","is_active":true,"creation_datetime":"2013-11-28T19:52:45.402Z","scope_note":"","parent":"http://taxonomy.nationalgeographic.com/api/v1/subjects/83bf00d5-93bd-3cca-acc3-543652f06d52","url":"http://taxonomy.nationalgeographic.com/api/v1/subjects/83c5f238-8dbc-373e-9d62-4deb4c59e122","name":"Expeditions","hierarchy":"exploration/expeditions/","uuid":"83c5f238-8dbc-373e-9d62-4deb4c59e122","notes":"","objectType":"org.ngs.taxonomy.Subject","groups":["Subject"],"english_name":null,"parentName":"Exploration"}</ngsTax:subject>
         <ngsTax:subject>{"updated_datetime":"2014-02-10T19:47:37.384Z","definition":"","is_active":true,"creation_datetime":"2014-01-16T17:48:21.375Z","scope_note":"","synonyms":[null,null,null],"parent":"http://taxonomy.nationalgeographic.com/api/v1/subjects/a817863e-de0f-3ffd-944d-c75ed20308ff","url":"http://taxonomy.nationalgeographic.com/api/v1/subjects/f0c33fd8-5e31-36b2-9229-b71628df3367","name":"Travel","hierarchy":"travel-and-adventure/travel/","uuid":"f0c33fd8-5e31-36b2-9229-b71628df3367","notes":"","objectType":"org.ngs.taxonomy.Subject","groups":["Subject"],"english_name":null,"parentName":"Travel and Adventure"}</ngsTax:subject>
         <ngsTax:title>NG Live!: Sheikh of the Arctic</ngsTax:title>
         <wpf:allTaxonomyId>18160</wpf:allTaxonomyId>
         <wpf:allTaxonomyId>1589</wpf:allTaxonomyId>
         <wpf:allTaxonomyId>858</wpf:allTaxonomyId>
         <wpf:altLinkedLegacyUrl />
         <wpf:author />
         <wpf:firstPublishedTime>Mon, 13 May 2013 19:11:17 GMT</wpf:firstPublishedTime>
         <wpf:id>13615</wpf:id>
         <wpf:lastPublishedTime>Mon, 03 Feb 2014 21:50:20 GMT</wpf:lastPublishedTime>
         <wpf:lineupName>Nat Geo Live 2</wpf:lineupName>
         <wpf:locationMigration>Arctic</wpf:locationMigration>
         <wpf:locationMigration>Antarctica</wpf:locationMigration>
         <wpf:metaKeyword>Nat Geo Live</wpf:metaKeyword>
         <wpf:metaKeyword>Nat Geo Live!</wpf:metaKeyword>
         <wpf:metaKeyword>lecture</wpf:metaKeyword>
         <wpf:metaKeyword>National Geographic Live</wpf:metaKeyword>
         <wpf:metaKeyword>National Geographic Live!</wpf:metaKeyword>
         <wpf:metaKeyword>NGLive</wpf:metaKeyword>
         <wpf:metaKeyword>NG Live</wpf:metaKeyword>
         <wpf:metaKeyword>Nat Geo Events</wpf:metaKeyword>
         <wpf:metaKeyword>Børge Ousland</wpf:metaKeyword>
         <wpf:metaKeyword>polar</wpf:metaKeyword>
         <wpf:metaKeyword>adventure</wpf:metaKeyword>
         <wpf:metaKeyword>explore</wpf:metaKeyword>
         <wpf:metaKeyword>exploration</wpf:metaKeyword>
         <wpf:metaKeyword>expedition</wpf:metaKeyword>
         <wpf:metaKeyword>ski</wpf:metaKeyword>
         <wpf:metaKeyword>North Pole</wpf:metaKeyword>
         <wpf:metaKeyword>loneliness</wpf:metaKeyword>
         <wpf:metaKeyword>strange</wpf:metaKeyword>
         <wpf:metaKeyword>visitor</wpf:metaKeyword>
         <wpf:metaKeyword>ice</wpf:metaKeyword>
         <wpf:metaKeyword>photo</wpf:metaKeyword>
         <wpf:metaKeywords>Nat Geo Live, Nat Geo Live!, lecture, National Geographic Live, National Geographic Live!, NGLive, NG Live, Nat Geo Events, Børge Ousland, polar, adventure, explore, exploration, expedition, ski, North Pole, loneliness, strange, visitor, ice, photo</wpf:metaKeywords>
         <wpf:organizationMigration>National Geographic Live</wpf:organizationMigration>
         <wpf:sitePath>Specials Video::Nat Geo Live::Nat Geo Live 2</wpf:sitePath>
         <wpf:siteUrlPath>/video/specials/nat-geo-live-specials/nat-geo-live-2/ousland-sheikh-bonus-nglive/</wpf:siteUrlPath>
         <wpf:subjectMigration>Explorers</wpf:subjectMigration>
         <wpf:subjectMigration>Expeditions</wpf:subjectMigration>
         <wpf:subjectMigration>Travel</wpf:subjectMigration>
         <wpf:taxonomyId>18160</wpf:taxonomyId>
         <ytcp:youTubeAssetType>web</ytcp:youTubeAssetType>
         <ytcp:youTubeSavedMatchRights>Monetize in all countries</ytcp:youTubeSavedMatchRights>
         <ytcp:youTubeSavedUsageRights>Monetize in all countries</ytcp:youTubeSavedUsageRights>
      </item>
   </channel>
</rss>

这是我的代码

   function parsexml($xml)
   {
   $xmlparse=simplexml_load_string($xml)
   var_dump($xmlparse);
   }

【问题讨论】：

你为什么不发布你试图解析这个xml文件的代码
我已从您的帖子（“plz”）中删除了 txtspk，对其进行了格式化以使标签可见（使用反引号），删除了可能在几个月后失效的外部链接，获得为您生成 XML，通过格式化程序将其传递，并将输出的 XML 复制到帖子中。这是相当多的维修工作，因此如果您将来可以这样做，将不胜感激。
下次我会记住的

标签： php xml parsing

【解决方案1】：

您不会获得所有节点，因为它们使用命名空间，例如：pl:id。要解析这些，您可以使用 Xpath。第一个示例获取所有pl:added 第二个示例获取media:hash。

如果您知道文件将始终使用相同的前缀，则只能使用以下内容。如果没有，您必须为您使用的每个 simpleXMLElement 对象注册命名空间。

<?    
$str = '*your string here*';    
$xml = simplexml_load_string($str);

// to get pl:added 
foreach($xml->xpath('//media:content') as $element) {
    $added = $element->xpath('//pl:added');
}
//output $added
echo "<pre>";
var_dump($added);

// to get media:hash
foreach($xml->xpath('//media:thumbnail') as $element) {
    $hash = $element->xpath('//media:hash');
}
//output $hash
echo "<pre>";
var_dump($hash);
?>

当您需要注册命名空间时，您可以执行以下操作。首先你可以 var dump 命名空间，这样你就知道你需要使用哪个 url。

["os"]=>string(36) "http://a9.com/-/spec/opensearch/1.1/" 所以对于操作系统，你需要那个 url。

<?    
$str = '*your string here*';    
$xml = simplexml_load_string($str);

// to get the namespaces uncomment the next 3 lines
// $namespaces = $xml->getNamespaces(true);
// echo "<pre>";
// var_dump($namespaces);

$xml->registerXPathNamespace('media', 'http://search.yahoo.com/mrss/');

foreach($xml->xpath('//media:content') as $element) {
    $element->registerXPathNamespace('pl', 'http://xml.theplatform.com/data/object');
    $added = $element->xpath('//pl:added');
}

echo "<pre>";
var_dump($added);

$xml->registerXPathNamespace('media', 'http://search.yahoo.com/mrss/');

foreach($xml->xpath('//media:thumbnail') as $element) {
    $element->registerXPathNamespace('media', 'http://search.yahoo.com/mrss/');
    $hash = $element->xpath('//media:hash');
}

echo "<pre>";
var_dump($hash);
?>

【讨论】：