Re: Implementing an ordered tree

	Except you can't call any set... methods in validateForSave without  
incurring the wrath of the gods. (Please don't call set methods in  
validation code. . . I can't believe I got to say this before Chuck  
Hill responded.) 	

	Wrapper methods that perform the behavior you want are what you're  
after here, I think. Skiena's Algorithm Design Handbook may cover this.



On Jan 23, 2006, at 9:18, YL wrote:

> validateForSave() is where i would put the logic for re-ordering.
>
> the idea:
> implement methods
> (1) checkChildrenOrder() that returns false if children array has  
> order
> problem
> (2) resetChildrenOrder() that loop over its children array and set  
> each
> one's order attribute to its index in the array.
>
> in  validateForSave(), you say
>
> validateForSave() {
>     super().validateForSave();
>     if(!checkChildrenOrder()) {
>           resetChildrenOrder();
>     }
> }
>
> ----- Original Message -----
> From: "Karoly Szantai" <[email protected]>
> To: <[email protected]>; <[email protected]>
> Sent: Monday, January 23, 2006 4:32 AM
> Subject: Implementing an ordered tree
>
>
> > Hello,
> >
> > I have a Category entity. Each Category has zero or more  
> subcategories,
> > which are ordered. There is a root Category (called main category)
> > which has no parent.
> > I have created this EO model:
> >
> > oid
> > oidParentCategory
> > name
> > ordinalNumber
> >
> > parentCategory (oidParentCategory --> oid)
> > subcategories (oid -->> oidParentCategory)
> >
> >
> > I need some hints on how to implement the following operations
> > (methods) with "ordered way":
> >
> > -add a category
> > -delete a category
> > -cut & paste a category (and its subcategories) from one level to
> > another level
> > -reorder categories (move a category in its level)
> > etc.
> >
> > My big headache is manipulating the ordinalNumber attribute in  
> "EO way".
> >
> >
> > Regards,
> > Karoly
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > WebObjects-dev mailing list
> > [email protected]
> > http://www.omnigroup.com/mailman/listinfo/webobjects-dev
> >
> >
> >
> > --
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> >
>
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