iReport Ultimate Guide - Nimsoft Library

Lists, Tables, and BarcodesList element variable1 has been defined in dataset1 as the sum of the C field—for each record the value of the variable isthe sum of the C fields of the elaborated records. By setting the evaluation time of the variable textfield to Report, we are ableto see the final value assumed by the variable (Figure 14-8).Figure 14-8List element with cumulative sum and evaluation time variables14.1.3 List Component IssuesWhat happens if we want to print, for each country, the percentage of orders with respect to the total? The percentagecalculation requires two values: the number of orders of the country (the value of C at evaluation time) and the total number oforders (the variable1 at evaluation time Report). The formula is pretty simple:C/variable1Since C and variable1 must be considered at different evaluation times, the evaluation time of the textfield showing thisresult must be set to Auto. However, here we have the first major limitation of the List component, which is that it cannot usethe evaluation time Auto! As a result, to print this percentage we need to use a subreport, or we can precalculate the final valueof variable1.283