xform group adding if condition to check if node exists

Hi All,

Could you please let me know how can we check if node not exists using xforms?
here is my template
<Item>
<name></name>
<desc></desc>
<hourType></hourType>
</Item>

So, I have added new node "hourType" in my existing template. Now the existing files (Which are generated by this template) will not have this node. So, I want to check if hourType node is not present.
For new files creation, it will be present for old node will not be present.


<xforms:group relevant="if (condition to check if node not present) then . else () " ref="if (condition to check if node not present) then . else () ">

Please help.

You could write:

<xf:group ref="if (exists(/Item/hourType)) then . else ()">

Don't use the relevant attribute on <xf:group>, as it won't have any effect. And we often write the above as follows, which is a bit shorter, but arguable not as clear:

<xf:group ref=".[exists(/Item/hourType)]">

Alex

Thanks Alex.

Can we use not exists
<xf:group ref="if (not exists(/Item/hourType)) then . else ()"> in group

Yes, you can do:

not(exists(…))

BTW, this is just normal XPath syntax, so you can also refer to books and online information about XPath, should you want to learn more about it.

Alex