Question

Trying to parse an iTunes Atom feed with a PHP script. If you visit the iTunes RSS Generator, you can generate an Atom feed like this:

http://itunes.apple.com/us/rss/topsongs/limit=10/genre=16/explicit=true/xml

which gives an iTunes RSS feed result like this:

<?xml version="1.0" encoding="utf-8"?>
<feed xmlns:im="http://itunes.apple.com/rss" xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
    <id>http://itunes.apple.com/us/rss/topsongs/limit=10/genre=16/explicit=true/xml</id><title>iTunes Store: Top Songs in Soundtrack</title><updated>2012-04-01T07:22:41-07:00</updated><link rel="alternate" type="text/html" href="http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewTop?id=17&amp;popId=1"/><link rel="self" href="http://itunes.apple.com/us/rss/topsongs/limit=10/genre=16/explicit=true/xml"/><icon>http://phobos.apple.com/favicon.ico</icon><author><name>iTunes Store</name><uri>http://www.apple.com/itunes/</uri></author><rights>Copyright 2008 Apple Inc.</rights>
        <entry>
            <updated>2012-04-01T07:22:41-07:00</updated>
                <id im:id="509605055">http://itunes.apple.com/us/album/eyes-open/id509605019?i=509605055&amp;uo=2</id>
                <title>Eyes Open - Taylor Swift</title>
                <im:name>Eyes Open</im:name>
                <link rel="alternate" type="text/html" href="http://itunes.apple.com/us/album/eyes-open/id509605019?i=509605055&amp;uo=2"/>
                <im:contentType term="Music" label="Music"><im:contentType term="Track" label="Track"/></im:contentType>
                <category term="Soundtrack" scheme="http://itunes.apple.com/us/genre/music-soundtrack/id16?uo=2" label="Soundtrack"/>

                <link title="Preview" rel="enclosure" type="audio/x-m4a" href="http://a2.mzstatic.com/us/r1000/116/Music/88/70/a6/mzi.gcauwkkw.aac.p.m4a" im:assetType="preview"><im:duration>30000</im:duration></link>

                <im:artist href="http://itunes.apple.com/us/artist/taylor-swift/id159260351?uo=2">Taylor Swift</im:artist>
                <im:price amount="1.29000" currency="USD">$1.29</im:price>
                <im:image height="55">http://a3.mzstatic.com/us/r1000/069/Music/v4/15/59/19/15591949-a525-99e8-0c50-45697b0ec78b/UMG_cvrart_00602527969206_01_RGB72_1200x1200_12UMGIM10247.55x55-70.jpg</im:image>
                <im:image height="60">http://a5.mzstatic.com/us/r1000/069/Music/v4/15/59/19/15591949-a525-99e8-0c50-45697b0ec78b/UMG_cvrart_00602527969206_01_RGB72_1200x1200_12UMGIM10247.60x60-50.jpg</im:image>
                <im:image height="170">http://a3.mzstatic.com/us/r1000/069/Music/v4/15/59/19/15591949-a525-99e8-0c50-45697b0ec78b/UMG_cvrart_00602527969206_01_RGB72_1200x1200_12UMGIM10247.170x170-75.jpg</im:image>
                <rights>2012 Universal Republic Records, a division of UMG Recordings, Inc.</rights>
                <im:releaseDate label="March 20, 2012">2012-03-20T00:00:00-07:00</im:releaseDate>
                <im:collection><im:name>The Hunger Games (Songs from District 12 and Beyond)</im:name><link rel="alternate" type="text/html" href="http://itunes.apple.com/us/album/hunger-games-songs-from-district/id509605019?uo=2"/><im:contentType term="Music" label="Music"><im:contentType term="Album" label="Album"/></im:contentType></im:collection>

(etc…)

With the PHP script, I’m able to get results for things like the title, id, im:image for each [entry] to use in the script output. What I need to get is the url from one of the link entries. Specially I need the url from the “Preview” link:

<link title="Preview" rel="enclosure" type="audio/x-m4a" href="http://a2.mzstatic.com/us/r1000/116/Music/88/70/a6/mzi.gcauwkkw.aac.p.m4a" im:assetType="preview"><im:duration>30000</im:duration></link>

In this case, we would need the a2.mzstatic.com/us/r1000/116/Music/88/70/a6/mzi.gcauwkkw.aac.p.m4a link for use in the script results for each of the 10 entries.

How do I capture that href for the .m4a audio file “Preview” link in the above Atom feed?

Here is a portion of the PHP script where we get the contents of the iTunes Atom url, cycle through the 10 results, and generate HTML for each entry via $rssresults that is called in a site template.

    $string = file_get_contents('http://itunes.apple.com/us/rss/topsongs/limit=10/genre=16/explicit=true/xml');

// Remove the colon ":" in the <xxx:yyy> to be <xxxyyy>
$string = preg_replace("/(<\/?)(\w+):([^>]*>)/", "$1$2$3", $string);

if ($f = @fopen($cache_file, 'w')) {
    fwrite ($f, $string, strlen($string));
    fclose($f);
    }
}
$xml = simplexml_load_string($string);

// Output
$rssresults = '';
$count = 1;
$max = 11;

foreach ($xml->entry as $val) {
    if ($count < $max) {

    $rssresults .= '
        <a href="'.$val->id.'" title="'.$val->title.'"><img src="'.$val->imimage[2].'" alt="'.$val->title.'"></a>

        // .m4a preview url?
        <div><a href=" ">Preview</div>

        <div><strong>'.$count.'. <a href="'.$val->id.'" title="'.$val->title.'">'.$val->title.'</a></strong></div>
        <div> from '.$val->imcollection->imname.'</div>;
    }
    $count++;
}

Any ideas on how to add the “.m4a preview url” to the above script for each entry?

Appreciate any help.

Answer 1

In your foreach loop try $val->link[1]["href"] would give you the URL

foreach ($xml->entry as $val) {
    // echo the link of Preview
    echo $val->link[1]["href"];
}

Explanation:
As there are multiple link entry you can access them by array index. So index 1 is used to access the second link entry. Each attribute of an Element can be accessed by its name as a key to the element. Hence $val->link[1]["href"] would give you http://a2.mzstatic.com/us/r1000/116/Music/88/70/a6/mzi.gcauwkkw.aac.p.m4a

Viper-7