Subject: Re: [xsl] Finding paths in Visio XML exports - recursion question|
From: Steven Davies <xsl-list@xxxxxxxxxxx>
Date: Sun, 28 Sep 2008 15:00:48 +0100
At 2008-09-27 20:20 +0100, Steven Davies wrote:Now, I can use an XPath expression to find the first node in the document easily enough (it has a certain property in its data set to "1") and the only way I've been able to find all connected shapes from this one is to use 3 for-each loops: the first over all <Connect>s beginning at the shape itself, the second nested loop over all other endpoints of the <Connect> (there will only ever be one) and the third over all <Shape>s connected to the <Connect>:
<xsl:variable name="thisShapeID" select="./@ID"/> <xsl:for-each select="../../v:Connects/v:Connect[@ToSheet=$thisShapeID and @FromCell='BeginX']"> <xsl:variable name="connectFromSheet" select="./@FromSheet"/> <xsl:for-each select="../v:Connect[@FromSheet=$connectFromSheet and @FromCell='EndX']"> <xsl:variable name="nextShapeID" select="./@ToSheet"/> <xsl:for-each select="../../v:Shapes/v:Shape[@ID=$nextShapeID]">
I had to use the xsl:variables because I couldn't get the equation
[@ID=./@ToSheet], for example, to work (it never matched, any ideas with this?).
Note that "./" as the first step of a location path doesn't do anything ... so where you have (for example) select="./@FromSheet" you need only have select="@FromSheet".
That is also why "[@ID=./@ToSheet]" is equivalent to "[@ID=@ToSheet]" which is why it isn't working for you.
You want "[@ID=current()/@ToSheet]" because in XSLT current() returns what the current node was when you started the XPath address. The current() function is not part of XPath but can be used with XPath in XSLT.
Inside the innermost xsl:for-each I recursively call the template which works very well for a straight flow in Visio. However, there can be infinite loops in the flow so I have to first test whether the <Shape> has already been output before recursing. This works.
Also the flows can branch off in multiple directions and each branch needs to be output one at a time (i.e. the nodes before the branch only need to be output once). This also works.
My problem is that I need to output a message (well, an element - eventually this will be XSL-FO) every time the end of a path is reached. This could be because the flow looped back, that is, the recursion is stopped, or it could be because the end of a branch (and therefore outermost for-each) was reached. While this is relatively easy to do, I end up getting multiple copies of the node output because of the multiple levels of recursion.
If you've stopped when your recursion loops back, how is it you are getting multiple levels of recursion?
Does anyone have an idea how to get around this?
A functioning mocked-up data example would help so that you could illustrate what is working and what isn't working. For myself I'm having problems understanding the prose description.
Thanks again, Steve