Parse XML namespaces with php SimpleXML

Question

I know this has been asked many many times but I haven't been able to get any of the suggestions to work with my situation and I have searched the web and here and tried everything and anything and nothing works. I just need to parse this XML with the namespace cap: and just need four entries from it.

<?xml version="1.0" encoding="UTF-8"?>
<entry>
    <id>http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFB832F0.SpecialWeatherStatement.124EFFB84164TX.LUBSPSLUB.ac20a1425c958f66dc159baea2f9e672</id>
    <updated>2013-05-06T20:08:00-05:00</updated>
    <published>2013-05-06T20:08:00-05:00</published>
    <author>
        <name>[email protected]</name>
    </author>
    <title>Special Weather Statement issued May 06 at 8:08PM CDT by NWS</title>
    <link href="http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFB832F0.SpecialWeatherStatement.124EFFB84164TX.LUBSPSLUB.ac20a1425c958f66dc159baea2f9e672"/>
    <summary>...SIGNIFICANT WEATHER ADVISORY FOR COCHRAN AND BAILEY COUNTIES... AT 808 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 30 MILES NORTHWEST OF MORTON...MOVING SOUTHEAST AT 25 MPH. NICKEL SIZE HAIL...WINDS SPEEDS UP TO 40 MPH...CONTINUOUS CLOUD TO GROUND LIGHTNING...AND BRIEF MODERATE DOWNPOURS ARE POSSIBLE WITH</summary>
    <cap:event>Special Weather Statement</cap:event>
    <cap:effective>2013-05-06T20:08:00-05:00</cap:effective>
    <cap:expires>2013-05-06T20:45:00-05:00</cap:expires>
    <cap:status>Actual</cap:status>
    <cap:msgType>Alert</cap:msgType>
    <cap:category>Met</cap:category>

    <cap:urgency>Expected</cap:urgency>
    <cap:severity>Minor</cap:severity>
    <cap:certainty>Observed</cap:certainty>
    <cap:areaDesc>Bailey; Cochran</cap:areaDesc>
    <cap:polygon>34.19,-103.04 34.19,-103.03 33.98,-102.61 33.71,-102.61 33.63,-102.75 33.64,-103.05 34.19,-103.04</cap:polygon>
    <cap:geocode>
        <valueName>FIPS6</valueName>
        <value>048017 048079</value>
        <valueName>UGC</valueName>

        <value>TXZ027 TXZ033</value>
    </cap:geocode>
    <cap:parameter>
        <valueName>VTEC</valueName>
        <value>
        </value>
    </cap:parameter>
</entry>

I am using simpleXML and I have a small simple test script set up and it works great for parsing regular elements. I can't for the dickens of me find or get a way to parse the elements with the namespaces.

Here is a small sample test script with code I am using and works great for parsing simple elements. How do I use this to parse namespaces? Everything I've tried doesn't work. I need it to be able to create variables so I can be able to embed them in HTML for style.

<?php 

$html = "";  

// Get the XML Feed
$data = "http://alerts.weather.gov/cap/tx.php?x=1";


// load the xml into the object
$xml = simplexml_load_file($data);

for ($i = 0; $i < 10; $i++){
    $title = $xml->entry[$i]->title;
    $summary = $xml->entry[$i]->summary;

    $html .= "<p><strong>$title</strong></p><p>$summary</p><hr/>";

}

 echo $html; 
?> 

This works fine for parsing regular elements but what about the ones with the cap: namespace under the entry parent?

<?php
ini_set('display_errors','1');

$html = "";
$data = "http://alerts.weather.gov/cap/tx.php?x=1";
$entries = simplexml_load_file($data);
if(count($entries)):
    //Registering NameSpace
    $entries->registerXPathNamespace('prefix', 'http://www.w3.org/2005/Atom');
    $result = $entries->xpath("//prefix:entry");
    //echo count($asin);
    //echo "<pre>";print_r($asin);
    foreach ($result as $entry):
        $title = $entry->title;
        $summary = $entry->summary;

        $html .= "<p><strong>$title</strong></p><p>$summary</p>$event<hr/>";

    endforeach;
endif;

echo $html;

?>

Any help would be greatly appreciated.

-Thanks

Answer 1

I have given same type of answer here - solution to your question

You just need to register Namespace and then you can work normally with simplexml_load_file and XPath

<?php
$data = "http://alerts.weather.gov/cap/tx.php?x=1";
$entries = file_get_contents($data);
$entries = new SimpleXmlElement($entries);
if(count($entries)):
    //echo "<pre>";print_r($entries);die;
    //alternate way other than registring NameSpace
    //$asin = $asins->xpath("//*[local-name() = 'ASIN']");

    $entries->registerXPathNamespace('prefix', 'http://www.w3.org/2005/Atom');
    $result = $entries->xpath("//prefix:entry");
    //echo count($asin);
    //echo "<pre>";print_r($result);die;
    foreach ($result as $entry):
        //echo "<pre>";print_r($entry);die;
        $dc = $entry->children('urn:oasis:names:tc:emergency:cap:1.1');
        echo $dc->event."<br/>";
        echo $dc->effective."<br/>";
        echo "<hr>";
    endforeach;
endif;

That's it.

Answer 2

Here's an alternative solution:

<?php
$xml = <<<XML
<?xml version = '1.0' encoding = 'UTF-8' standalone = 'yes'?>
<?xml-stylesheet href='http://alerts.weather.gov/cap/capatom.xsl' type='text/xsl'?>

<!--
This atom/xml feed is an index to active advisories, watches and warnings 
issued by the National Weather Service.  This index file is not the complete 
Common Alerting Protocol (CAP) alert message.  To obtain the complete CAP 
alert, please follow the links for each entry in this index.  Also note the 
CAP message uses a style sheet to convey the information in a human readable 
format.  Please view the source of the CAP message to see the complete data 
set.  Not all information in the CAP message is contained in this index of 
active alerts.
-->

<feed
    xmlns = 'http://www.w3.org/2005/Atom'
    xmlns:cap = 'urn:oasis:names:tc:emergency:cap:1.1'
    xmlns:ha = 'http://www.alerting.net/namespace/index_1.0'
    >
<!-- http-date = Tue, 07 May 2013 04:14:00 GMT -->

<id>http://alerts.weather.gov/cap/tx.atom</id>
<logo>http://alerts.weather.gov/images/xml_logo.gif</logo>
<generator>NWS CAP Server</generator>
<updated>2013-05-06T23:14:00-05:00</updated>
<author>
    <name>[email protected]</name>
</author>
<title>Current Watches, Warnings and Advisories for Texas Issued by the National Weather Service</title>
<link href='http://alerts.weather.gov/cap/tx.atom'/>

<entry>
    <id>http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFB8AA78.FireWeatherWatch.124EFFD70270TX.EPZRFWEPZ.1716207877d94d15d43d410892b9f175</id>
    <updated>2013-05-06T23:14:00-05:00</updated>
    <published>2013-05-06T23:14:00-05:00</published>
    <author>
        <name>[email protected]</name>
    </author>
    <title>Fire Weather Watch issued May 06 at 11:14PM CDT until May 08 at 10:00PM CDT by NWS</title>
    <link href="http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFB8AA78.FireWeatherWatch.124EFFD70270TX.EPZRFWEPZ.1716207877d94d15d43d410892b9f175"/>
    <summary>...CRITICAL FIRE CONDITIONS EXPECTED WEDNESDAY ACROSS FAR WEST TEXAS AND THE SOUTHWEST NEW MEXICO LOWLANDS... .WINDS ALOFT WILL STRENGTHEN OVER THE REGION EARLY THIS WEEK...AHEAD OF AN UPPER LEVEL TROUGH FORECAST TO MOVE THROUGH NEW MEXICO AND TEXAS ON WEDNESDAY. SURFACE LOW PRESSURE WILL ALSO DEVELOP TO OUR EAST AS THE TROUGH APPROACHES. THIS COMBINATION WILL RESULT</summary>
    <cap:event>Fire Weather Watch</cap:event>
    <cap:effective>2013-05-06T23:14:00-05:00</cap:effective>
    <cap:expires>2013-05-08T22:00:00-05:00</cap:expires>
    <cap:status>Actual</cap:status>
    <cap:msgType>Alert</cap:msgType>
    <cap:category>Met</cap:category>
    <cap:urgency>Future</cap:urgency>
    <cap:severity>Moderate</cap:severity>
    <cap:certainty>Possible</cap:certainty>
    <cap:areaDesc>El Paso; Hudspeth</cap:areaDesc>
    <cap:polygon></cap:polygon>
    <cap:geocode>
        <valueName>FIPS6</valueName>
        <value>048141 048229</value>
        <valueName>UGC</valueName>
        <value>TXZ055 TXZ056</value>
    </cap:geocode>
    <cap:parameter>
        <valueName>VTEC</valueName>
        <value>/O.NEW.KEPZ.FW.A.0018.130508T1900Z-130509T0300Z/</value>
    </cap:parameter>
</entry>

<entry>
    <id>http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFABB2F0.AirQualityAlert.124EFFC750DCTX.HGXAQAHGX.7f2cf548a67d403f0541492b2804d621</id>
    <updated>2013-05-06T14:16:00-05:00</updated>
    <published>2013-05-06T14:16:00-05:00</published>
    <author>
        <name>[email protected]</name>
    </author>
    <title>Air Quality Alert issued May 06 at 2:16PM CDT by NWS</title>
    <link href="http://alerts.weather.gov/cap/wwacapget.php?x=TX124EFFABB2F0.AirQualityAlert.124EFFC750DCTX.HGXAQAHGX.7f2cf548a67d403f0541492b2804d621"/>
    <summary>...OZONE ACTION DAY FOR TUESDAY... THE TEXAS COMMISSION ON ENVIRONMENTAL QUALITY (TCEQ)...HAS ISSUED AN OZONE ACTION DAY FOR THE HOUSTON...GALVESTON...AND BRAZORIA AREAS FOR TUESDAY...MAY 7 2013. ATMOSPHERIC CONDITIONS ARE EXPECTED TO BE FAVORABLE FOR PRODUCING HIGH LEVELS OF OZONE POLLUTION IN THE HOUSTON...GALVESTON AND</summary>
    <cap:event>Air Quality Alert</cap:event>
    <cap:effective>2013-05-06T14:16:00-05:00</cap:effective>
    <cap:expires>2013-05-07T19:15:00-05:00</cap:expires>
    <cap:status>Actual</cap:status>
    <cap:msgType>Alert</cap:msgType>
    <cap:category>Met</cap:category>
    <cap:urgency>Unknown</cap:urgency>
    <cap:severity>Unknown</cap:severity>
    <cap:certainty>Unknown</cap:certainty>
    <cap:areaDesc>Brazoria; Galveston; Harris</cap:areaDesc>
    <cap:polygon></cap:polygon>
    <cap:geocode>
        <valueName>FIPS6</valueName>
        <value>048039 048167 048201</value>
        <valueName>UGC</valueName>
        <value>TXZ213 TXZ237 TXZ238</value>
    </cap:geocode>
    <cap:parameter>
        <valueName>VTEC</valueName>
        <value></value>
    </cap:parameter>
</entry>
</feed>
XML;

$sxe       = new SimpleXMLElement($xml);
$capFields = $sxe->entry->children('cap', true);

echo "Event: " . (string) $capFields->event . "\n";
echo "Effective: " . (string) $capFields->effective . "\n";
echo "Expires: " . (string) $capFields->expires . "\n";
echo "Severity: " . (string) $capFields->severity . "\n";

Output:

Event: Fire Weather Watch
Effective: 2013-05-06T23:14:00-05:00
Expires: 2013-05-08T22:00:00-05:00
Severity: Moderate