Dan,
Thank you for your answer.
Actually my solution same as yours at last.
I modify defaultxxx function do not increase sequenceNumber to avoid
side-effects.
Database store next new sequence;
And show sequenceNumber default value to user.
2015-07-29 13:58 GMT+08:00 Dan Haywood <d...@haywood-associates.co.uk>:
> Apologies for not replying sooner on this one.
>
> I was going to reply that you shouldn't make any assumptions about how many
> times the supporting methods are called, and in general that's true... they
> should have no side-effects. After all, the user could hit cancel, in
> which case (in your original implementation) the sequence number would
> still have been incremented.
>
> In your particular use case, if the idea is that the system will
> automatically generate a value for the sequence number but the user can
> override, I would simply provide no default; then the logic to calculate
> the next value should be in the action itself, eg:
>
> public MaintainRequest newMaintainRequest(String sequenceNumber, ...) {
> if(sequenceNumber == null) {
> SequenceGenerator seq = seqGens.findGenerator();
> Integer n=seq.getSequnceNumber();
> n++;
> seq.setSequenceNumber(n);
> sequenceNumber = ""+ seqGens.getSequenceNumber();
> }
> ...
> }
>
> That said , I had a quick look at the Wicket UI code, and it turns out to
> be easy enough to change things to prevent the defaultXxx(...) being called
> multiple times. So I've raised and committed a fix for ISIS-1179.
>
> Thanks
> Dan
>
>
>
>
> On 13 July 2015 at 02:20, Chuangyu <zhu.chuan...@gmail.com> wrote:
>
> > Hi,
> > I create a defaultXXX method,in this method it fetchs a sequence number
> > like below
> >
> > public Integer default0NewMaintainRequest(){
> > SequenceGenerator seq=seqGens.findGenerator();
> > Integer n=seq.getSequnceNumber();
> > n++;
> > seq.setSequenceNumber(n);
> > return n;
> > }
> >
> > But it was called 2 times when invoke newMaintainRequest(Integer
> > code.....), and sequence number was plus 2 every time.
> >
> > How can I avoid this behavior ?
> >
>
