我不是一个出色的网络开发人员，我需要从amazon api feed中获取每个YouTube视频的链接。每个条目都有多个“链接”元素，我需要抓取<link rel="alternate">节点。
以下是我正在解析的内容：
<?xml version='1.0' encoding='UTF-8'?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" xmlns:openSearch="http://a9.com/-/spec/opensearchrss/1.0/" xmlns:gd="http://schemas.google.com/g/2005" xmlns:gml="http://www.opengis.net/gml" xmlns:yt="http://gdata.youtube.com/schemas/2007" xmlns:georss="http://www.georss.org/georss">
<id>http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE</id>
<updated>2012-08-02T23:50:11.000Z</updated>
<category scheme="http://schemas.google.com/g/2005#kind" term="http://gdata.youtube.com/schemas/2007#playlist" />
<title type="text">Julio Jones: Falcons Wide Receiver</title>
<subtitle type="text" />
<logo>http://www.youtube.com/img/pic_youtubelogo_123x63.gif</logo>
<link rel="alternate" type="text/html" href="http://www.youtube.com/playlist?list=PL07B32D2A9CDF22DE" />
<link rel="http://schemas.google.com/g/2005#feed" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE" />
<link rel="http://schemas.google.com/g/2005#batch" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/batch" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE?start-index=1&max-results=3" />
<link rel="next" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE?start-index=4&max-results=3" />
<author>
<name>Atlanta Falcons</name>
<uri>http://gdata.youtube.com/feeds/api/users/AtlantaFalconsNFL</uri>
</author>
<generator version="2.1" uri="http://gdata.youtube.com">YouTube data API</generator>
<openSearch:totalResults>28</openSearch:totalResults>
<openSearch:startIndex>1</openSearch:startIndex>
<openSearch:itemsPerPage>3</openSearch:itemsPerPage>
<media:group>
<media:content url="http://www.youtube.com/p/PL07B32D2A9CDF22DE" type="application/x-shockwave-flash" yt:format="5" />
<media:thumbnail url="http://i.ytimg.com/vi/Rm5tLcAxXAs/default.jpg" height="90" width="120" yt:name="default" />
<media:thumbnail url="http://i.ytimg.com/vi/Rm5tLcAxXAs/mqdefault.jpg" height="180" width="320" yt:name="mqdefault" />
<media:thumbnail url="http://i.ytimg.com/vi/Rm5tLcAxXAs/hqdefault.jpg" height="360" width="480" yt:name="hqdefault" />
<media:title type="plain">Julio Jones: Falcons Wide Receiver</media:title>
</media:group>
<yt:playlistId>PL07B32D2A9CDF22DE</yt:playlistId>
<entry>
<id>http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsq-4gxYn2Tr2d2FeqOBspw</id>
<published>2012-08-02T23:49:43.000Z</published>
<updated>1970-01-01T00:00:00.000Z</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="Sports" label="Sports" />
<title type="text">WR Julio Jones Soaking Up Veteran Knowledge</title>
<content type="text">It's widely known that Roddy White has had a huge impact on the development of Julio Jones, but another perrenial Pro Bowler on the other side of the line of scrimmage is helping groom the second-year rising star.</content>
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=fUdXu_BT7zQ&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/fUdXu_BT7zQ/responses" />
<link rel="http://gdata.youtube.com/schemas/2007#video.related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/fUdXu_BT7zQ/related" />
<link rel="http://gdata.youtube.com/schemas/2007#mobile" type="text/html" href="http://m.youtube.com/details?v=fUdXu_BT7zQ" />
<link rel="related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/fUdXu_BT7zQ" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsq-4gxYn2Tr2d2FeqOBspw" />
<author>
<name>atlantafalconsnfl</name>
<uri>http://gdata.youtube.com/feeds/api/users/atlantafalconsnfl</uri>
</author>
<gd:comments>
<gd:feedLink rel="http://gdata.youtube.com/schemas/2007#comments" href="http://gdata.youtube.com/feeds/api/videos/fUdXu_BT7zQ/comments" countHint="13" />
</gd:comments>
<georss:where>
<gml:Point>
<gml:pos>34.1851 -83.92518</gml:pos>
</gml:Point>
</georss:where>
<yt:hd />
<media:group>
<media:category label="Sports" scheme="http://gdata.youtube.com/schemas/2007/categories.cat">Sports</media:category>
<media:content url="http://www.youtube.com/v/fUdXu_BT7zQ?version=3&f=playlists&app=youtube_gdata" type="application/x-shockwave-flash" medium="video" isDefault="true" expression="full" duration="143" yt:format="5" />
<media:content url="rtsp://r2---sn-p5qlsu7s.c.youtube.com/CiULENy73wIaHAk071Pwu1dHfRMYDSANFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="143" yt:format="1" />
<media:content url="rtsp://r2---sn-p5qlsu7s.c.youtube.com/CiULENy73wIaHAk071Pwu1dHfRMYESARFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="143" yt:format="6" />
<media:description type="plain">It's widely known that Roddy White has had a huge impact on the development of Julio Jones, but another perrenial Pro Bowler on the other side of the line of scrimmage is helping groom the second-year rising star.</media:description>
<media:keywords />
<media:player url="http://www.youtube.com/watch?v=fUdXu_BT7zQ&feature=youtube_gdata_player" />
<media:thumbnail url="http://i1.ytimg.com/vi/fUdXu_BT7zQ/0.jpg" height="360" width="480" time="00:01:11.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/fUdXu_BT7zQ/1.jpg" height="90" width="120" time="00:00:35.750" />
<media:thumbnail url="http://i1.ytimg.com/vi/fUdXu_BT7zQ/2.jpg" height="90" width="120" time="00:01:11.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/fUdXu_BT7zQ/3.jpg" height="90" width="120" time="00:01:47.250" />
<media:title type="plain">WR Julio Jones Soaking Up Veteran Knowledge</media:title>
<yt:duration seconds="143" />
</media:group>
<gd:rating average="5.0" max="5" min="1" numRaters="13" rel="http://schemas.google.com/g/2005#overall" />
<yt:recorded>2012-08-02</yt:recorded>
<yt:statistics favoriteCount="0" viewCount="4240" />
<yt:description>It's widely known that Roddy White has had a huge impact on the development of Julio Jones, but another perrenial Pro Bowler on the other side of the line of scrimmage is helping groom the second-year rising star.</yt:description>
<yt:position>1</yt:position>
</entry>
<entry>
<id>http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsjKrxurClwVOmQ3lb41H7L</id>
<published>2012-08-01T16:25:32.000Z</published>
<updated>1970-01-01T00:00:00.000Z</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="Sports" label="Sports" />
<title type="text">Tuesday's Training Camp: Quick Hits</title>
<content type="text">In the final practice before the first day off of 2012 Russell Falcons Training Camp, the new offensive and defensive schemes continued to gel.</content>
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=Rm5tLcAxXAs&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/Rm5tLcAxXAs/responses" />
<link rel="http://gdata.youtube.com/schemas/2007#video.related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/Rm5tLcAxXAs/related" />
<link rel="http://gdata.youtube.com/schemas/2007#mobile" type="text/html" href="http://m.youtube.com/details?v=Rm5tLcAxXAs" />
<link rel="related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/Rm5tLcAxXAs" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsjKrxurClwVOmQ3lb41H7L" />
<author>
<name>atlantafalconsnfl</name>
<uri>http://gdata.youtube.com/feeds/api/users/atlantafalconsnfl</uri>
</author>
<gd:comments>
<gd:feedLink rel="http://gdata.youtube.com/schemas/2007#comments" href="http://gdata.youtube.com/feeds/api/videos/Rm5tLcAxXAs/comments" countHint="1" />
</gd:comments>
<georss:where>
<gml:Point>
<gml:pos>34.1851 -83.92518</gml:pos>
</gml:Point>
</georss:where>
<yt:hd />
<media:group>
<media:category label="Sports" scheme="http://gdata.youtube.com/schemas/2007/categories.cat">Sports</media:category>
<media:content url="http://www.youtube.com/v/Rm5tLcAxXAs?version=3&f=playlists&app=youtube_gdata" type="application/x-shockwave-flash" medium="video" isDefault="true" expression="full" duration="79" yt:format="5" />
<media:content url="rtsp://r4---sn-p5qlsu7e.c.youtube.com/CiULENy73wIaHAkLXDHALW1uRhMYDSANFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="79" yt:format="1" />
<media:content url="rtsp://r4---sn-p5qlsu7e.c.youtube.com/CiULENy73wIaHAkLXDHALW1uRhMYESARFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="79" yt:format="6" />
<media:description type="plain">In the final practice before the first day off of 2012 Russell Falcons Training Camp, the new offensive and defensive schemes continued to gel.</media:description>
<media:keywords />
<media:player url="http://www.youtube.com/watch?v=Rm5tLcAxXAs&feature=youtube_gdata_player" />
<media:thumbnail url="http://i1.ytimg.com/vi/Rm5tLcAxXAs/0.jpg" height="360" width="480" time="00:00:39.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/Rm5tLcAxXAs/1.jpg" height="90" width="120" time="00:00:19.750" />
<media:thumbnail url="http://i1.ytimg.com/vi/Rm5tLcAxXAs/2.jpg" height="90" width="120" time="00:00:39.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/Rm5tLcAxXAs/3.jpg" height="90" width="120" time="00:00:59.250" />
<media:title type="plain">Tuesday's Training Camp: Quick Hits</media:title>
<yt:duration seconds="79" />
</media:group>
<gd:rating average="5.0" max="5" min="1" numRaters="4" rel="http://schemas.google.com/g/2005#overall" />
<yt:recorded>2012-08-31</yt:recorded>
<yt:statistics favoriteCount="0" viewCount="1233" />
<yt:description>In the final practice before the first day off of 2012 Russell Falcons Training Camp, the new offensive and defensive schemes continued to gel.</yt:description>
<yt:position>2</yt:position>
</entry>
<entry>
<id>http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsGRJhgHr8YqbDzzp1um-HX</id>
<published>2012-08-01T16:25:32.000Z</published>
<updated>1970-01-01T00:00:00.000Z</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="Sports" label="Sports" />
<title type="text">Scenes from Monday: Quick Hits</title>
<content type="text">Line blocking and footwork drills, receivers working on their routes and various special teams reps highlight this video glimpse at Monday afternoon's training camp practice.</content>
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=5bESx10p3_Y&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/5bESx10p3_Y/responses" />
<link rel="http://gdata.youtube.com/schemas/2007#video.related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/5bESx10p3_Y/related" />
<link rel="http://gdata.youtube.com/schemas/2007#mobile" type="text/html" href="http://m.youtube.com/details?v=5bESx10p3_Y" />
<link rel="related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/5bESx10p3_Y" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/playlists/PL07B32D2A9CDF22DE/PLTL9ir3vNAXsGRJhgHr8YqbDzzp1um-HX" />
<author>
<name>atlantafalconsnfl</name>
<uri>http://gdata.youtube.com/feeds/api/users/atlantafalconsnfl</uri>
</author>
<gd:comments>
<gd:feedLink rel="http://gdata.youtube.com/schemas/2007#comments" href="http://gdata.youtube.com/feeds/api/videos/5bESx10p3_Y/comments" countHint="4" />
</gd:comments>
<georss:where>
<gml:Point>
<gml:pos>34.1851 -83.92518</gml:pos>
</gml:Point>
</georss:where>
<yt:hd />
<media:group>
<media:category label="Sports" scheme="http://gdata.youtube.com/schemas/2007/categories.cat">Sports</media:category>
<media:content url="http://www.youtube.com/v/5bESx10p3_Y?version=3&f=playlists&app=youtube_gdata" type="application/x-shockwave-flash" medium="video" isDefault="true" expression="full" duration="103" yt:format="5" />
<media:content url="rtsp://r4---sn-p5qlsu7k.c.youtube.com/CiULENy73wIaHAn23yldxxKx5RMYDSANFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="103" yt:format="1" />
<media:content url="rtsp://r4---sn-p5qlsu7k.c.youtube.com/CiULENy73wIaHAn23yldxxKx5RMYESARFEgGUglwbGF5bGlzdHMM/0/0/0/video.3gp" type="video/3gpp" medium="video" expression="full" duration="103" yt:format="6" />
<media:description type="plain">Line blocking and footwork drills, receivers working on their routes and various special teams reps highlight this video glimpse at Monday afternoon's training camp practice.</media:description>
<media:keywords />
<media:player url="http://www.youtube.com/watch?v=5bESx10p3_Y&feature=youtube_gdata_player" />
<media:thumbnail url="http://i1.ytimg.com/vi/5bESx10p3_Y/0.jpg" height="360" width="480" time="00:00:51.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/5bESx10p3_Y/1.jpg" height="90" width="120" time="00:00:25.750" />
<media:thumbnail url="http://i1.ytimg.com/vi/5bESx10p3_Y/2.jpg" height="90" width="120" time="00:00:51.500" />
<media:thumbnail url="http://i1.ytimg.com/vi/5bESx10p3_Y/3.jpg" height="90" width="120" time="00:01:17.250" />
<media:title type="plain">Scenes from Monday: Quick Hits</media:title>
<yt:duration seconds="103" />
</media:group>
<gd:rating average="5.0" max="5" min="1" numRaters="3" rel="http://schemas.google.com/g/2005#overall" />
<yt:recorded>2012-07-30</yt:recorded>
<yt:statistics favoriteCount="0" viewCount="1381" />
<yt:description>Line blocking and footwork drills, receivers working on their routes and various special teams reps highlight this video glimpse at Monday afternoon's training camp practice.</yt:description>
<yt:position>3</yt:position>
</entry>
</feed>
我猜它是这样的：
foreach($xml->entry as $entry){
//echo $entry->title . "<br>";
// echo count($entry->link) . "<br>";
echo $entry->link[rel="alternate"];
// echo "<a href=\"". $entry->link->attribute() . "\">" . $entry->title . "</a>" . "<br>";
}
但我不确定。任何帮助都会很棒！
我也很好奇如何将这些信息从mvc设置（codeigniter）传递到视图中作为显示最近视频的模型，但这不是一个非常紧迫的问题。
答案 0 :(得分：0)
我会尝试像
这样的东西if($entry->link['rel'] === 'alternate'){ echo etc... }
答案 1 :(得分：0)
使用xpath：
$simplexml_load_string($x); // assume XML in $x
$xml->registerXPathNamespace('m', 'http://www.w3.org/2005/Atom');
$links = $xml->xpath("//m:link[@rel='alternate']/@href");
数组$links将包含href个属性的<link>个属性，其rel属性包含alternate。输出这样的值：
foreach ($links as $link) echo "$link <br />";
看到它有效：http://3v4l.org/BPueX
答案 2 :(得分：0)
我知道我对这个答案有点迟了：
foreach ($xml->entry as $entry){
//For each loop determining how many videos to display based on how many
//entries there are in the feed.
$nameSpaces = $entry->getNameSpaces(true);
$yt = $entry->children($nameSpaces['yt']);
$mediayt = $entry->children($nameSpaces['media'])->group->children($nameSpaces['yt']);
//Hooray for namespaces... not.
$link = $entry->link[0]['href'];
//Grabs the first of four links. The third link is for mobile and
//has a cleaner URL but does not work with Swipebox.
$id = basename($entry->id);
//Gets the id for each video.
$title = $entry->title;
//Gets the title for each video.
$published = date('dS M Y', strtotime($entry->published));
//Gets the published date of each video and displays it by
//Day Month Year. If not set will display 31st Dec 1969
$content = $entry->content;
//Gets the video description, if any.
$ytRecorded = date('dS M Y', strtotime($yt->recorded));
//Gets the recorded date of each video and displays it by
//Day Month Year. If not set will display 31st Dec 1969
$ytDuration = gmdate("i:s",(int) $mediayt->duration['seconds']);
//Gets the video duration in seconds and convert it to
//Minutes:Seconds(00:00)
$ytViewCount= $yt->statistics['viewCount'];
//This will get the view count for each video.
}
如您所见，您不需要xpath，attributes（）或任何tom-foolery来获取多个条目。另一方面，命名空间很荒谬。
您可以指定数组中的第一个[0]，以及['href']之后的属性。