|
I
absolutely love the format and formatKey attributes of bean:write tag in Struts
framework. You can use these attributes to format the display of your form bean
properties. This works pretty well in displaying currency and date/time values.
For example, you can display 1234.567 as $1,234.57 and 08/12/2006 as Aug 12,
2006. Here is how it works:
<bean:write
name="myForm" property="amount"
format="$#,000.00" />
OR
<bean:write
name="myForm" property="amount"
formatKey="myapp.currency.format" />
AND
myapp.currency.format=$#,000.00
(in resource bundle)
The
preferred way is to use the second format because it makes the code portable.
Plus, if you want to change the format, you can make the change in resource
bundle without having to worry about changing all your JSPs.
So
far so good. When I tried to use this feature in one of my recent projects, it
didn't work! Why? Because the type of the property being formatted cannot be
String. The format attribute simply uses default format (display the property
as is) when the property is of type java.lang.String. In other words,
private
double amount; // will be formatted correctly
private
String amount; // will NOT be formatted at all
This
could be a feature or a limitation but I haven't been able to figure out why
String shouldn't work! Why
do I expect the format attribute to do the type conversion? Because the
framework automatically does the type conversion on form submission. Here is
what I mean by that:
//
action form code
public
class MyForm extends ActionForm{
private double amount;
}
//
jsp code
<html:text
name="myForm" property="amount" />
Even
though request.getParameter("amount") returns a String, the framework
happily converts the String to double. If this conversion is automatic, why
can't it convert String to double and try to display the value in currency
format in the format attribute? I am sure this has been
raised/discussed/considered somewhere but I can't find it. If some one knows
let me know.
There
is another problem (not really a Struts problem though). There is no way to
format phone numbers. If you get a String 8001234567 from the database and
would like to convert to (800) 123-4567 OR 800-123-4567, currently there is no
tag or attribute to do that (or I don't know about it). I was hoping, since
it's so easy to format currency and date objects, it would be easy to format
phone numbers but looks like it's my challenge to write something like that.
| 
