The JSTL spec is a great reference. I would recommend you download it. robert
> -----Original Message----- > From: as as [mailto:[EMAIL PROTECTED] > Sent: Friday, March 05, 2004 8:48 AM > To: Struts Users Mailing List > Subject: RE: Sorting table columns in jsp using struts > > > Henri, > > Thanks for the explanatory smaples.The syntax below seems JSTL.... > <c:forEach var="category" items="${requestScope.categories}"> > <tr> > <td><a > Any quick intro I read on JSTL... > Thanks > > Henri Yandell <[EMAIL PROTECTED]> wrote: > > Just to show how easy it can be with beanutils: > > display_categories.do points to a struts action that preloads like: > > ***** > List list = new ArrayList(); > list.addAll( DummyDao.getAllCategories() ); > String sortBy = request.getParameter("sortBy"); > if(sortBy != null) { > BeanComparator comparator = new BeanComparator(sortBy); > Collections.sort( list, comparator ); > } > request.setAttribute( "categories", list ); > return mapping.findForward("success"); > ***** > > and the jsp page that success points to contains: > > **** > > > name > description > > > > > > > > > > > **** > > where Category has 'name' and 'description' as properties. This handles > things with natural sorting. Doing the reverse sort used to be pretty > easy, but is harder now that we separate the view and model [as the model > wants to record view-state, or maybe the view wants to record model-view > state...ugh]. > > The trick is by having: > > if(reverse) { > comparator = new ReverseComparator(comparator); > } > > after the BeanComparator line. The only complication is where you decide > to store reverse. You can use the session, or as you'll probably want > little arrows showing the sort direction, you can write it into the > column-header with '?sortBy=name&reverse=true'. This can be tricky and > probably involves the Action storing things in the request scope for the > jsp to discover later. > > Anyway, I assume the display-tag library contains this pretty much, but > Comparators are lovely so it can't hurt to babble on about them :) > > Hen > > On Thu, 4 Mar 2004, as as wrote: > > > Thanks in advance. > > Sam > > (I am currently truying out display tag though, as per Ashish) > > > > Henri Yandell wrote: > > > > I imagine display tags does it for you mostly if you go that way, else > > I'll knock up an example tonight. Finally getting back into taglibs and > > jsp :) > > > > Hen > > > > On Thu, 4 Mar 2004, as as wrote: > > > > > thanks much. > > > sample code by any cance? > > > Thank you! > > > > > > ~~Sam > > > > > > Henri Yandell wrote: > > > > > > BeanUtils' BeanComparator is a useful way to do the sorting by the way, > > > and will be in your classpath if you're using Struts [depending on > > > version]. > > > > > > Also ReverseComparator in Commons Collections. Between them you can write > > > a nice abstract table sorting system. > > > > > > Hen > > > > > > On Thu, 4 Mar 2004, as as wrote: > > > > > > > Wendy, > > > > > > > > Thanks for the quick reply. > > > > books is a session attribute (request.setParameter("books",books) > > > > I retrieve books from database - Book.java > > > > so books is a "List" object. > > > > Will try your approach and post back the results > > > > Thanks, > > > > Sam~~ > > > > > > > > > > > > Wendy Smoak wrote: > > > > Sam wrote: > > > > > Any clues on best easy ways to do table column sorting > > > > > my rows in the table are generated as follows using > > > > > as below. > > > > > > > > I do it on the server side, holding the items to be sorted in a Map and > > > > creating a new Map passing a Comparator to the constructor to get the > > > > new order. Then when you're back on the JSP iterating over it, the > > > > items are in the "correct" order. > > > > > > > > Map accountMap = (Map) session.getAttribute( "accountMap" ); > > > > Map newMap = new TreeMap( new CostCenterComparator() ); > > > > newMap.putAll( accountMap ); > > > > session.setAttribute( "accountMap", newMap ); > > > > > > > > [Comments welcome, I'm not sure this is the best way to do it, but it > > > > works...] > > > > > > > > What type of Collection is 'books' in your example? > > > > > > > > -- > > > > Wendy Smoak > > > > Application Systems Analyst, Sr. > > > > ASU IA Information Resources Management > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > --------------------------------- > > > > Do you Yahoo!? > > > > Yahoo! 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