[EMAIL PROTECTED] wrote:
>
> This is the approach that I am using, but to simplify the design I have
> interconnected the view and model. I would like to eliminate this coupling-
> so if anyone has some suggestions or could recommend a pattern I could apply
> please let me know :) What I am doing is creating entity beans that resemble
> the ActionForm as much as possible- for the most part there is a loose 1 to
> 1 relationship between entity EJB and ActionForm. There are some exceptions,
> but this is how 80% of the app is designed. I use session EJBs to manage the
> entity EJBs and map these to appropriate ActionForms (using the Struts
> copyProperties util). So, the session EJB must be aware of the ActionForm,
> since this is the object that it returns. To persist data, the ActionServlet
> obtains a reference to the session EJB and would send a save() method I have
> implemented the ActionForm which then is copied to an entity EJB. Ideally
> there should be a proxy between the EJB tier and the Struts tier, so the
> session EJB does not need to be aware of the ActionForm. But, I am not about
> to create another intermediate object with the same properties and
> setters/getters. Some of my forms have up to 30 properties so this is way
> too much work! I think this should be done automatically.
>
> One more thing- the copyProperties requires that properties are the same
> type. But, the view is basically just String-based where the ejb tier
> consists of real Date, BigDecimal, etc... So what I find myself doing is
> creating additional methods in the ActionForm that make this transformation.
> For example setCustomerId(BigDecimal) and setCustomerIdStr(String). Then use
> the string version for Struts, and when copyProperties is invoked it will
> map the BigDecimal value to the EJB. Perhaps I should extend copyProperties
> to support basic type conversions- or has this already been done elsewhere?
>
> thoughts or suggestions?
Bob,
I can see what you mean. The
RequestUtils.populate(Object bean, String prefix, String suffix,
HttpServletRequest request)
methods do no type conversions.
So do you call the additional conversion methods during the validate()
method on the ActionForm?
I am very new to struts as is, but as I far as I can tell from reading
the implementation of the above method,
the ActionForm can only have String properties. Is this correct?
If so, it would be nice if the ActionForm could support types other than
String and the
struts engine would convert these in a similar fashion as Ant does to
the attributes in the xml build file.
An error message could be returned to the user if they entered a String
into an Integer field, say.
This behavour may not be always desired, so it could be switched on and
off in the <Action>.
This may open a can of worms however, Date formats spring to mind.
However, comming from a background of using tags in anger, I wrote a lot
of code
converting Strings to other objects, (mostly Longs, ints, (B)booleans ).
Just my 2 Bobs worth.
cheers,
Nick
>
> Thanks,
> Bob
>
> -----Original Message-----
> From: Nick Pellow [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, February 27, 2001 5:23 PM
> To: [EMAIL PROTECTED]
> Subject: Re: Stupd question about Struts and EJB.
>
> Hello,
>
> Robert Leland wrote:
> >
> > As far as struts 1.0, the Form bean is used only to redisplay
> > information to the jsp page. Typically the EJB might be loaded/unloaded in
> the
> > action class. If you search www.mail-archives.co,m Craig talked more about
> this in detail.
>
> My understanding is that with struts you should keep your EJBs entirely
> independant of
> anything to do with struts or servlets. You can and should however have
> a standard naming
> convention for the getters and setters across the EJB, the ActionForm
> and the html form elements.
> this allows you to call PropertyUtils.copyProperties(java.lang.Object
> dest, java.lang.Object orig)
> when you are ready to store the details entered by the user.
>
> Please let me know if this does not sound right.
>
> Cheers,
> Nick
>
> > In future version of struts this may be enhanced.
> >
> > -Rob
> >
> > > Cameron Ingram0 wrote:
> > >
> > > I am in the process of convincing my company to go with MVC and Struts.
> As with any thing new,
> > > people are sometimes resistant
> > > to change. One of the opposition questions I am getting is, how will
> this work with EJB(problem is
> > > I don't know too much about EJB currently). Do the EJB's references
> just go in the Form and
> > > Action Bean and every thing else behaves the same? Are there any obvious
> points that I can bring
> > > up on the subject?
> > > Any help on this subject would be much appreciated!
> > >
> > > Thanks, Cameron Ingram
