Quick PHP Tip: How to parse CDATA sections using SimpleXML

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Quick PHP Tip: How to parse CDATA sections using SimpleXML

September 22nd, 2009 | Posted by Vijay Joshi | 3 Comments

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Applies to: simplexml_load_string and simplexml_load_file

Problem : SimpleXML does not parse text inside CDATA tags in an XML.

Consider the XML below:


$str = '';
$str.='some text goes here';
$str.='';

To parse it we use following syntax:

$xml = simplexml_load_string($str);

On printing it outputs:


SimpleXMLElement Object
(
    [childNode] => some text goes here
)

Thats OK. Now the same xml but this time the text is enclosed in CDATA tags.


$str = '';
$str.='';
$str.=''

On printing this gives following output:


SimpleXMLElement Object
(
    [childNode] => SimpleXMLElement Object
        (
        )

)

Yes its empty. This is because SimpleXML does not parse CDATA tags. All data enclosed within CDATA is ignored by SimpleXML parser.

Solution: Set the 3rd parameter to LIBXML_NOCDATA while parsing.

simplexml_load_string(simplexml_load_file too) actually takes 3 parameters.

The string to parse
Optional parameter – to return an object of class specified in this parameter. (By default it returns a SimpleXMLElement Object)
Also optional – libxml parameters can be specified as options. This option provides the solution to our CDATA problem

Provide the 3rd parameter LIBXML_NOCDATA and SimpleXML will consider CDATA nodes as text nodes and will parse them.


$xml = simplexml_load_string($str,'SimpleXMLElement', LIBXML_NOCDATA);

This will output as desired:


SimpleXMLElement Object
(
    [childNode] => some text goes here
)

Please note that using the third parameter requires PHP >=5.1 compiled with libxml.

I will be publishing a new post shortly on how to use SimpleXML to parse xml and extract data.

Posted in : FAQ, PHP
Tags: FAQ, PHP, xml

3 Comments to “Quick PHP Tip: How to parse CDATA sections using SimpleXML”

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Rajaraman says:

July 29, 2010 at 11:23 am

thanks

Reply
dVyper says:

January 13, 2011 at 8:41 pm

This has proved very helpful thanks!

Reply
andrew says:

September 18, 2011 at 1:13 pm

Have following PHP which gives me car hire location, time and date but i cannot seem to extract the CDATA? All data comes from the following and included in this is CDATA

$string=”http://www.thrifty.co.uk/cgi-bin/gen5?runprog=thxml&xsrc=7qhfqou3&mode=quote”;

Any ideas????

$value )
{
$value = ( array ) $value ;
if ( isset ( $value [ 0 ] ) )
{
$newArray [ $key ] = trim ( $value [ 0 ] ) ;
}
else
{
$newArray [ $key ] = XML2Array ( $value , true ) ;
}
}
return $newArray ;
}

function disp_date($str)
{
$y=substr($str,0,4);
$m=substr($str,4,2);
$d=substr($str,6,2);
//echo $y.”-”.$m.”-”.$d;
return date(“M d, Y”,strtotime($y.”-”.$m.”-”.$d));
}

$handle = fopen($string, “r”);
$xml_string=”";
// If there is something, read and return
if ($handle) {
while (!feof($handle)) {
$buffer = fgets($handle, 4096);
$xml_string.=$buffer;
}
fclose($handle);
}

//$xmlDoc = new DOMDocument();
$xmlDoc=simplexml_load_string ( $xml_string ) ;

//print_r($xmlDoc);

echo “Zipcode: “.$xmlDoc->hire->loccode.”Location Name: “.$xmlDoc->hire->locname.”Pickup Time: “.disp_date($xmlDoc->hire->pickupdate).” “.$xmlDoc->hire->pickuptime.”Dropback Time: “.disp_date($xmlDoc->hire->dropbackdate).” “.$xmlDoc->hire->dropbacktime.”";

echo “Car TypeDescriptionRate”;
foreach($xmlDoc->car as $car)
{
echo “carimage.”‘ align=’right’ style=’padding:5px; width:64px’>“.$car->cartype.”“.$car->carsipp.”".$car->transmission.”“.$car->carexample.”£”.$car->price.”/dayUnlimited Miles”;
}
echo “”;
?>

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