On Thu, 18 Jul 2002, Andrew Hill wrote:
> Date: Thu, 18 Jul 2002 14:29:22 +0800
> From: Andrew Hill <[EMAIL PROTECTED]>
> Reply-To: Struts Users Mailing List <[EMAIL PROTECTED]>,
> [EMAIL PROTECTED]
> To: Struts Users Mailing List <[EMAIL PROTECTED]>
> Subject: RE: Arrgh!!! my property has been cursed and my bean doesnt
> like the field on my farm , uhh form I mean
>
> Ah well now, its funny you should be mentioning that.
>
> As it happens Old Mc Andrew did once have a method to set the field with a
> boolean, but changed it to take a string instead as he is quite set in his
> ways and has never liked booleans (as he learnt from a young age that
> providing a certain true or false answer instead of 'maybe' tends to create
> a few too many expectations in folk not wise to the ways of software
> development...).
>
> He has looked at his ActionForm code to try and determine is there is a
> second setter somewhere (he even looked behind the grassyKnoll() method) but
> found nothing. Old McAndrew has been known to occasionally miss things that
> are right under his nose however, and will continue to look.
>
> There ARE however multiple getter methods, or to be precise there is a
> method getHeaderTransform() and an isHeaderTransform() the latter of the
> two returning a boolean. (The other similar fields also have these but they
> still work.)
>
Despite their protestations to the contrary, having two getters like this
is also a violation of the rules (the JavaBeans rules, that is). It would
also be improper to have a getter that returns one type, and a setter that
accepts a different one.
"So where are these rules?" you might ask. "How can I avoid such faux pas
in the future?"
http://java.sun.com/products/javabeans/
has a link that gets you to the JavaBeans specification, which includes a
whole chapter on how well mannered JavaBeans properties expose themselves
to the world.
Craig
> -----Original Message-----
> From: Craig R. McClanahan [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, July 18, 2002 14:05
> To: Struts Users Mailing List; [EMAIL PROTECTED]
> Subject: Re: Arrgh!!! my property has been cursed and my bean doesnt
> like the field on my farm , uhh form I mean
>
>
>
>
> On Thu, 18 Jul 2002, Andrew Hill wrote:
>
> > Date: Thu, 18 Jul 2002 13:23:02 +0800
> > From: Andrew Hill <[EMAIL PROTECTED]>
> > Reply-To: Struts Users Mailing List <[EMAIL PROTECTED]>,
> > [EMAIL PROTECTED]
> > To: Struts Users Mailing List <[EMAIL PROTECTED]>
> > Subject: Arrgh!!! my property has been cursed and my bean doesnt like
> > the field on my farm , uhh form I mean
> >
> > Or to be a little bit more specific...
> >
> > Old Mc Andrew had a form
> > and on that form he had a field
> > with the name "headerTransformation"
> > but naughty Mr Struts simply would NOT call the method
> > setHeaderTransformation in his ActionForm
> > even though it had not been a problem yesterday!
> >
>
> I hope old McAndrew isn't trying to have his cake and eat it too, by
> having more than one mistress, err, setHeaderTransformation() method that
> takes a different type of argument :-). Such things violate the JavaBeans
> specification's design patterns, and will cause the JVM to think your
> property doesn't have any setter method at all.
>
> > No matter what Andrew looked at everything still seemed fine but it just
>
> >
> > didnt work!
> > He tried changing the field from a checkbox to a boring old text field
> > He tried dumping the request parameters to see if anything was dodgy there
> > - maybe multiple values were being submitted for that property?
> > but no - it all checked out ok, no matter where he looked.
> > Poor Andrew was getting VERY alarmed.
> >
> > Then he had a clever idea!
> > He changed the name of the field on his html form to
> "headerTransformationx"
> > ,
> > he also added a second setter named setHeaderTransformationx to his
> > actionform and then tried again.
> > Amazing! This time it worked!
> > Mr Struts went right ahead and called the setHeaderTransformationx method.
> > Andrew couldnt believe his eyes.
> >
>
> Makes it even more likely that old McAndrew is trying to double dip :-).
> After all, a property named "headerTransformationx" is completely naive
> and innocent about the existence of any property named
> "headerTransformation".
>
> > Just to test he renamed the field back to "headerTransformation"
> > and sure enough nasty Mr Struts gave it the cold shoulder again.
> >
> > Now Andrew is very confused. He hasnt the slightest clue why a parameter
> > named
> > "headerTransformation" is completely ignored by Mr Struts, while a
> parameter
> > named "headerTransformationx" is welcomed with open arms!
> >
> > Well boys and girls, perhaps you can help poor Andrew with his problem?
> > Can anyone give him a reason why silly Mr Struts has a bad attitude
> towards
> > his fieldnames?
> >
>
> Mr. Struts is like Miss Manners -- he frowns on trying to have serious
> relationships with two property setters at the same time :-).
>
> >
> > <details>
> > Ive looked at the request parameters (dumping them from processPopulate()
> in
> > the request processor just before the form is populated.
> > headerTransformation=xxx is in there alright, and its not multiple values.
> > So it fine there,
> > but the setter in the actionForm is not getting called.
> >
> > The code in my actionform is:
> >
> > public void setHeaderTransformationx(String value)
> > {
> > System.out.println("Setting headerTransformationx to " + value);
> > _headerTransformation = value;
> > }
> >
> > public void setHeaderTransformation(String value)
> > {
> > System.out.println("Setting headerTransformation to " + value);
> > _headerTransformation = value;
> > }
> >
> > public String getHeaderTransformation()
> > {
> > return _headerTransformation;
> > }
> >
> > I also set _headerTransformation to null in the reset() method (it used to
> > be a checkbox before I started trying to diagnose the problem).
> >
> > And my html form has a field with the code:
> >
> > <input type="text" name="headerTransformationx"
> > onchange="submitWithMethod('update');"/>
> > (or
> > <input type="text" name="headerTransformation"
> > onchange="submitWithMethod('update');"/>
> > depending on which of the two setters Im testing)
> >
> > When I use the headerTransformationx name it works, but
> headerTransformation
> > does not.
> >
> > I have several other fields on the form that are specified in an almost
> > identical manner , the only difference being their name, and they all work
> > sweet.
> >
>
> Well, Mr. Struts may be perverse, but at least he is *consistently*
> perverse :-).
>
> > Very confused :-(
> > </detail>
>
> Please check for having more than one setter method with the same name but
> different argument types. That is the 99.9%-of-the-time cause for this
> sort of difficulties.
>
> Craig
>
>
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