I'm reading a really good book at the moment, "JSTL : Practical Guide for JSP Programmers"
-----Original Message----- From: as as [mailto:[EMAIL PROTECTED] Sent: 05 March 2004 13:48 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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