问题
I'm trying to display an image using an xml file and SimpleXML
The XML code is
<icons>
<icon size="tiny" href="/FF02-tiny.jpg" />
<icon size="sidebar" href="/FF02-sidebar.jpg" />
<icon size="full" href="/FF02-full.jpg" />
</icons>
I want to get the href attribute for the size="full" line.
I've tried
icons->icon->attributes()->href
but this just gives me the first 'tiny' size. I know I should be using xpath but I am lost.
回答1:
$icons->icon will give you a SimpleXMLElement object that gives access to all icon child-elements of the $icons object.
From there you need to select which icon you want to get the attribute for. That works with array-like access and a numeric value for the zero-index child element and a string value for the attribute:
// specify what icon you want (third)
// and the attribute (href)
$icons->icon[2]['href'];
You find that documented in the PHP manual with the SimpleXML basic examples (Example #3 and Example #5).
However this does not work if the position of the element you look for changes. So it's suggested that you use a more specific xpath-expression instead.
回答2:
Yes, you can select the attribute node with an xpath expression:
list($iconHref) = $xml->xpath("//icon[@size='full']/@href");
echo $iconHref;
来源：https://stackoverflow.com/questions/14979588/selecting-attribute-values-based-on-another-attribute-value-with-simplexml