Re: Root[1] vs Root (2)

[Branko N. <bra...@in...>]

Thank you for nice explanation, Nigel. I'm also very thankful fur code 
modification.
Unfortunately my test shows error. After downloading the latest XPath 
from CVS, I tried to use

$set  =  $x1->match("//document", "/root/folder[3]");

but results have been from whole document, not only from folder[3],
with php error *"Notice*: Undefined offset: 1 in *XPath.class.php* on 
line *2126"*.

Cheers,
Branko


Nigel Swinson wrote:

>>>I've noticed that root absolute path need to be numbered as root[1]:
>>>   $set  =  $x1->match("//document", "/root[1]/folder[3]");
>>>
>>>In case without [1] after root
>>>   $set  =  $x1->match("//document", "/root/folder[3]");
>>>have got error:
>>>*XPath error in XPath.class.php:2121* The supplied xPath '//document'
>>>does not *uniquely* describe a node in the xml document.
>>>
>>>Seems strange to me, as root is always the only one.
>>>      
>>>
>
>Wherever the class takes an xPathQuery, you can miss out the [] if there is
>only one relevant node, but where the class takes an absoluteXPath, that
>particular argument isn't "pre evaluated" so you have to provide an
>absoluteXPath. "/root" isn't a node in the document, but "/root[1]" is.
>"/root" is an XPath expression (an xPathQuery) that evaluates to precisely
>one node it so happens, so what we can do is to evaluate() on the /root,
>then check that it returns only one node.
>
>Your code will be faster if you supply the [] though, as it means that the
>class does not needlessly have to evaluate the /root XPath expression only
>to find out that there is only one root node.
>
>Never-the-less to make the class easier to use, I've upgraded the second
>parameter of match() for you to an xPathQuery rathar than an absoluteXPath,
>and demand that the xPathQuery evaluate to a single node.
>
>Cheers
>
>Nigel
>
>  
>