xpath query to xpath result of query
Question
for example we have this xml:
<body>
<a>
<b>
<c>hello</c>
<c>world</c>
</b>
</a>
<a>
<b>
<c>another hello</c>
<c>world</c>
</b>
</a>
</body>
by Xpath query we can find all "B"-tags. But then we need to find all "C"-tags in every found "B"-tag. I wrote this code:
$dom = new DOMDocument();
$dom->loadXML($xml);
$xpath = new DOMXPath($dom);
$btags = $xpath->query("//b");
foreach ($btags as $b)
{
$ctags = $xpath->query("/b/c", $b);
foreach ($ctags as $c) {
echo $c->nodeValue;
}
}
But it doesn't work. It possible to do this with XPath query's?
3 answers
solution1
8 ACCPTED 2010-06-26 00:57:05
For your second XPath, try this instead: $ctags = $xpath->query("c", $b);
This second XPath is already relative to the 'b' node...if I'm not mistaken, relative pathing in PHP XPath statements requires that you omit the leading '/'.
solution2
0 2012-08-14 20:43:38
Robert Hui is not mistaken
FYI //b selects all elements that are type b anywhere in the document but using / means to select the root node, thus /b/c is trying to select the root node b that has a child node c . The root node is the body element.
solution3
0 2010-06-26 00:12:41
You're already at the 'b' element by the time you get to the second query. What your code is looking for is "//b/b/c". Try using just "/c" in the second query instead. You could also move this into one query with "//b/c" if you aren't looking to do anything with "b".
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