How to find XML position based on id attribute (xpath?)

andrew_embassy

I need to make a function that will enable people to change the order of a list of clients stored in xml. So I figured I'd just go

function moveUpDn($id,$upDn)

Where $id is the node I want to move, and $upDn is either 'up' or 'down' meaning I move it up or down one node.

So I go to make my queries,

$current_q = "//client[@id='" . $currentID . "']";

but then I can't find anything that'll allow me to get the position of a node... I can get a node based on a position, but not the other way around-

Ideas?

andrew_embassy

So I figured I might be able to do this by just getting the node I'm interested in and the nextSibling info, could that work? So far I don't know if it's bad coding on my part of if I'm barking up the wrong tree.

Norman_Graham

Hi Andrew

I don't know a great deal about XML, although I have been reading about XSLT and XPath quite extensively of late.

However, it seems to me that XML is not the ideal format for putting things in numerical or alphabetical order. I think of XML as a good way of storing data and meta-data. Things like sorting according to some criteria are done when you want to transfer the data to a DB or convert it to a display format such as XHTML. That's where XSLT comes in - it does the sorting.

If you want each client to have a particular sort order in the XML doc, I would imagine you would need a tag (e.g. <order>) with a value which is an integer or string. You could then search the XML doc according to this tag and either do some simple string-replacement stuff, use SimpleXML to make changes or employ XSLT with variable values to convert the XML doc.

Finally - this may be a load of rubbish and in fact there's an easy way to do what you want, but I thought I'd at least try and help.

Norman

andrew_embassy

Hey Norman- thanks for the help, that makes sense. The application I've got going is pretty simple, and I think I can make it all work with php, but it's good to know all that about XSL and such - thanks!

Andrew