Grails UI for Integer Dates

Legacy tables often have dates kept in integer, zoned, or packed fields. This is unfortunate because the UI developer has to do all the validation and formatting of the numeric value. But there's a simple solution for Grails applications: create getter/setter methods to simulate a Date attribute.

Grails' generate-view will use the g:datePicker tag in the create and edit GSPs. Typically I replace g:datePicker with the RichUi tag.

In the following example, the domain has an integer sales date, in month/day/year format but getSaleDate() and setSaleDate() surfaces a Date attribute. The trick is to not present the integer date attribute for update (otherwise the value will overwrite the change made by setSaleDate()).

class Sale {
 String     last
 int    saleMDY
 BigDecimal amount

 Date getSaleDate() {
  Calendar cal = Calendar.getInstance();
  if (!saleMDY) {
   return new Date()
  }
  int year = (saleMDY % 100)
  int day = saleMDY / 100
  int month = day / 100
  day %= 100
  cal.set((2000+year), (month-1), day)
  return cal.time
 }
 void setSaleDate(Date date) {
  Calendar cal = Calendar.getInstance();
  cal.setTime(date)
  int day = cal.get(Calendar.DAY_OF_MONTH)  
  int month = cal.get(Calendar.MONTH) + 1 
  int year = cal.get(Calendar.YEAR) % 100
  saleMDY = (month * 10000) + (day * 100) + year
 }
}