On 05.07.2007 18:26, Grzegorz Kossakowski wrote:
I had a feeling that there is much more besides Date/Number/Currency
formatting but now I think that I was suffering from over-generalization
problem. The converter concept is that simple how you describe it but
it's not wrong because it solves very concrete problem.
Hopefully it goes beyond simple date, number or currency formatting!
With Spring's usage of PropertyEditors you can bind objects directly to
a selection list. You don't care how it gets converted to string and
back, the PropertyEditor does it. The CForms way is more complicated
[1], you have to convert your collection to a
org.apache.cocoon.forms.datatype.SelectionList.
In my Spring MVC project I have written one (!) EntityPropertyEditor
which is used for all domain entities in my application. Now in JSP
using Spring's form taglib I just write:
Which company do you want to work for?
<form:select path="user.selectedCompany" items="${companies}"
itemLabel="name"/>
"user" is the object the form is bound to.
"selectedCompany" is a property of the use and of type entity or
company, not a entity id or something like that.
"companies" is a collection of entities/companies, e.g. retrieved from
RequestContext.
"name" is a property of the entity/company, here used as label.
That's all. No selection list generation. No caring about the key. The
<option> in the <select> is correctly preselected if there was one set
on the user. I get a company instance set on user.selectedCompany property.
<jx:formatDate value="${myobj.startDate}" dateStyle="short"
locale="${cocoon.request.locale}">
for each date. That is of course quite OK to write, but it clearly
clutters the code, and it is not that obvious for a non developer.
With converters it would be more like:
${myobj.startDate#short}
Isn't that only a shorter syntax?
The focus on template formatting is rather limiting. IMO it MUST be a
two-way process or you can't write back to the object model. Selecting
the converter in the template makes it just impossible.
We might have a different focus in mind. But if we talk about a general
converter concept we should not start with such a limitation.
Joerg
[1] http://cocoon.apache.org/2.1/userdocs/widgetconcepts/selectionlists.html
