Issue when comparing values in repeat section in Orbeon forms

Question

I am working on Orbeon forms and i have a functionality related issue as explained below. I have a form which has repeat fields as below which is to be added dynamically by clicking on 'Add' button. I have two fields in the repeat section.And also i have a condition like the fields must be compared with the one in the same row and also with the one which is in the previous and also in the next row.

I have an instance like this:

 1.constraint="if(.!='')
         then
       (. < ../two and . > ../preceding::number/two)
       else
       true()"/>
 2.constraint="if(.!='' )
    then 
    (. > ../one  and . < ../following-sibling::number/one)
    else
    true()"/>


 <number> is under repeat condition. 
 1.In this,i am trying to compare number/one with <two> in the same row and the     preceding row.
 2.In this,i am trying to compare number/two with <one> in the same row and the     next preceding row.

 I have to add like 10 times of these fields.When it is added after 3rd time,the logic doesn't work properly.

 Kindly let me know what happens in this case.

Answer 1

Unqualified preceding-sibling and following-sibling xpath expressions return a sequence of all preceding or following siblings.

You need to add a predicate to select the previous or next sibling.

So, for your example:

../preceding-sibling::number[1]/two

or. more fully

../preceding-sibling::number[position()=1]/two

will return the previous sibling "two" element.

An example integer comparison:

(. > xs:integer(../preceding-sibling::number[1]/two))

See http://blog.orbeon.com/2007/06/xpath-reverse-axis-evil-at-times_04.html for more.

Regards

Jez