REXML XPath bug?

Ruby
1

I’m having trouble with a particular XPATH in REXML and would greatly
appreciate any help.

Given this simple document…

xxx
yyy

The xpath “//div[@class=‘summary’]/following-sibling::div/span” is
failing to return ‘yyy’.

Here’s a console dump that also shows a simplier xpath working.

REXML::XPath.match(doc, “//div[@class=‘summary’]/following-sibling::div/span”).to_s
=> “”

REXML::XPath.match(doc, “//div[@class=‘summary’]/following-sibling::div”).to_s
=> “

\nyyy\n
”

puts doc.to_s

xxx
yyy

The xpath works fine in firefox’s xpath checker, so it seems like an
issue with rexml.
Any help greatly appreciated.

  • Andy
2

On Wed, 14 May 2008 15:00:47 -0500, Andy W. wrote:

I’m having trouble with a particular XPATH in REXML and would greatly
appreciate any help.
(rest of it quoted below)

Ok, I tested this with JEdits XPATH tool and indeed, the xpath “//div
[@class=‘summary’]/following-sibling::div” returns the span-element with
string-value yyy, xml fragment yyy.

Is it a bug? I must admit I would need to read more references etc
before
being able to say definately - or is it just different interpretation of
the following-sibling -axis. Dont have the time to see the rfc atm.

But I played around a bit:
irb(main):046:0> puts root.elements[“//div[@class=‘summary’]/following-
sibling::div/span”]
nil

  • So, it doesnt work like that.

irb(main):047:0> puts root.elements[“//div[@class=‘summary’]/following-
sibling::div”]

yyy
* hmm....

irb(main):049:0> puts root.elements[“//div[@class=‘summary’]/
following::div/span”]
yyy
** Would this work in your case?

ALSO - you could include the rexml namespace by adding the line
include REXML
after the rexml requires. This way you wont have to use the long ::-
syntax, but can refer to document or elements directly, and use xpaths
simply as above inside [“”].

I also played around with this http://www.zvon.org:9001/saxon/cgi-bin/
XLab/XML/xpatut_15.html and following seems to accomplish what you need.

Finally, just plain-jane /div/span would select the span but maybe there
can be many and you only want the one after the summary div.

Out of time, gtg

Casimir P.