title: Xpages how to obtain/create this calculations module
body: <p>We have to achieve some task consisting in some calculations ( recursive calculations ) based on some fields values inside the doc. Let say, for example, creating some invoices.</p>
  
  <p>IN some old classic lotus notes applications, we just created a table with 24 rows and 4 columns, in every cell being an editable / computed field. You can imagine what kind of formulas we entered in each field, considering the fact that the current fields row were based on the value of the previous fields row and so on.</p>
  
  <p>In xpages, my scenario was to create a button which shows a dialog where the invoice structure is. Completing all the fields and then save/hide the dialog, the doc. &lt; invoice > will be listed on an (embedded) view inside the main document. the current opened dialog / invoice will take consideration on the previous invoice values. Obviously, there would be some disadvantages, the first I noticed was: let say my view lists 5 invoices. If I open for editing the 2nd one, I modify some field => from the 3rd to the last one, will be all be changing on this last edit? </p>
  
  <p>Is there any sample snippet from I could get inspired or a simple module of this type ofcalculations?</p>
  
  <p>I would like some advices and some helpful tips/suggestions. Also, I will appreciate any important considerations that I should be beware of. </p>