designer

166 Chapter 5 Working with Data Views
example of a situation in which you need to edit the XSLT in Code view is to work with
calculated columns.
By default, SharePoint provides two columns for each numeric column. One column
provides the numeric values for a list item, and the second column provides the presentation
format of that numeric value. When the numeric column represents a currency,
for example, the values in the presentation column contain commas, dots, and currency
symbols. To calculate the sum of those currency values, you use the numeric column. If
you use the presentation column to complete mathematical computations, the XPath
expression results in an error, and the acronym NaN is displayed. The numeric column
has the same name as the related presentation column but with a dot appended to the
name.
Calculated columns do not have a related numeric column. Therefore, choosing the correct
column to use in your XPath expressions is not a simple task. The solution that you
use in the following exercise computes the function of the nodes first, capturing the
results in an XSL variable as a result-tree fragment, which is subsequently transformed
using the msxsl:node-set function that can then be used as input to the sum function. If
you do not want to create your own XLST code, when you configure the calculated column
do not select the data type returned for the formula as Currency. Instead, create an
additional column to store the currency symbol, such as $, EUR, and £.
See Also Other XSLT sum solutions can be found in “Recipe 3.6. Computing Sums and
Products” in the XSLT Cookbook by Sal Mangano (O’Reilly), which is available at flylib.com/
books.php?ln=en&n=2&p=765&c=45&p1=1&c1=1&c2=208&view=1.
In this exercise, you use the Insert Formula dialog box and amend the XSLT code in Code
view to correct two group totals that have a value of NaN.
SET UP Using SharePoint Designer, open the site you used in the previous exercise
if it is not already open, and then open CreateDVWP.aspx in edit mode with the
SalesReport DFWP selected.
Formula
1. In the List Price column, click NaN, and then on the Options tab, click Formula.
Tip You may have to click NaN again to highlight it.
The Insert Formula dialog box opens, and in the Edit The XPath Expression box, the
formula sum($nodeset/@ListPrice) is displayed. If the formula is not displayed, close
the Insert Formula dialog box and repeat step 1.
2. Place the insertion point between Price and ), and then type a period (.). Click OK.
The Insert Formula dialog box closes, and NaN is replaced by 760.