[XSLLIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: Count a substring of an attribute in childnodes
> I tried > select="sum(number(colspec[contains(@colwidth,'*')]/substring > before(@colwidth,'*')))" > instead, but this does not work either. The number() function returns a single number. Summing over a single number obviously isn't going to do any good. You're thrashing around rather than thinking about the problem clearly. Your problem has the general form: 1) select a set of nodes 2) for each node, compute a number 3) find the sum of the numbers This is often referred to as the "sum of price times quantity" problem, though in your case the computation in step 2 is slightly different. Let's solve the general problem by saying that in step 2, we want to call a function f(node)>number. Having got a general solution, it's then easy to apply it to your case and to many other similar cases just by changing the function f. In XPath 2.0 the solution can be written sum(for $n in $nodes return f($n)) or more concisely sum($nodes/f(.)) You've been offered two solutions for XSLT/XPath 1.0, and I'll add a third. The first solution is recursion. Cutting out the XSLT noise, the solution can be expressed: total($nodes): choose when count($nodes)=0 return 0 otherwise return f($nodes[1]) + total($nodes[position()>1]) The second solution is Dimitre's functional programming approach. This is the one that's closest to the way I expressed the problem above. Note that I described a threestage approach in which stage 2 involves computing some function. This is a classic higherorder function. The threestep algorithm is a function that takes two arguments: the sequence of nodes, and the function to be computed in step 2. Dimitre's FXSL library allows you to write the solution in this form. It takes some getting used to, but it's the most economical way of solving the problem; and although it involves calling the FXSL library, that's written in pure XSLT 1.0 so it should be completely portable. The third solution uses the pipeline design pattern mentioned in my mail earlier today. Here you do the job in two steps. The output of the first step is a tree in which the elements carry an attribute that's the computed number (the value of f(node)). The second step uses the sum() function to sum over these attributes. Michael Kay http://www.saxonica.com/

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