It could be done. I'm pretty sure that if you used onComponentTag (can't remember exact name this second - and just walking out the door) - you could read any attribute from the tag. Then hold that number in your component and let your model that reads the songs read that number to determine how many.
-- Jeremy Thomerson http://www.wickettraining.com On Mon, Sep 7, 2009 at 6:10 PM, Chris Colman <chr...@stepaheadsoftware.com>wrote: > When my web designer guy wants control over whether he wants to place > either 10 songs or 50 songs into the 'top of the charts' panel I > consider that to be something that should definitely not be something we > have to make separate .java panel classes and markup to achieve. > > To have to get a programmer to adjust code to change the number of items > displayed in a list would be the subject of thunderous laughter in any > desktop app development environment - but yet I see that web app > development changes all the rules about what's funny and what's not =) > > In every other aspect of OO coding since 1990 a scenario like this would > cause a big light bulb in my head to go off and the word > 'parameterization' would start blinking at me incessantly. > > We programmer propeller heads can do all the smarts on the Java side to > use a single 'SongChartPanel' to display any number of songs from a list > based on a single parameter - so long as we can get that parameter > somehow. It's still MVC because NO code exists in the presentation layer > - only a parameter is now able to be passed in. > > The value of that parameter is not considered code. Setting up a > parameter is something a web design guy can 'understand' (they set > parameter/attribute values on HTML tags all day long) and it's something > that directly affects the presentation side that he would want control > over. That gives him power. > > Without this power I have to get the programmers to create a different > panel and markup for each different song chart panel even though the > code will be exactly the same except for the terminating condition of a > for loop. That's not OO and it's not reusability. It would be funny if > it wasn't true! > > Let's say we make > > SongChartTop10Panel and SongChartTop50Panel > > (with .java and .html markup for each) > > Now he says he wants to make a top 20 list for one page and a top 40 > list for another page... the inefficiency and non OO nature of this > approach becomes apparent. > > If a simple parameter were able to be passed to the panel we could reuse > that panel code to show anywhere from 1 to n songs. > > Please don't confuse a parameter (numbers, identifiers etc.,) with logic > (algorithms, conditional statements etc.,). No one is suggesting we put > logic into the presentation layer - the pain of JSP is much too firmly > burnt into my brain to ever step away from MVC again ;) > > > > -----Original Message----- > > From: Jeremy Thomerson [mailto:jer...@wickettraining.com] > > Sent: Tuesday, 8 September 2009 8:19 AM > > To: users@wicket.apache.org > > Subject: Re: Passing parameters from markup to panels > > > > Put simply, no. In Wicket, this is considered code. And code goes in > > Java > > files. Configure it in the YourPage.java file - where you have access > to > > data sources, session attributes, the user, etc.... > > > > -- > > Jeremy Thomerson > > http://www.wickettraining.com > > > > > > > > On Mon, Sep 7, 2009 at 5:09 PM, Chris Colman > > <chr...@stepaheadsoftware.com>wrote: > > > > > I apologize in advance if there is a completely obvious solution to > this > > > that I have missed... > > > > > > Is it possible to "pass in" parameters to a panel via the markup? > > > > > > Eg., Let's say that there are number of different ways that a > particular > > > panel could be rendered and that these ways are largely determined > by > > > the choice of data source or perhaps even the amount of data to > display > > > (from a collection for example). > > > > > > Now let's say that I wanted to provide some level of control over > which > > > data source is chosen by allowing the user to pass in an extra > > > 'parameter' in the markup when declaring the panel in the source > markup > > > like: > > > > > > <span wicket:id="myPanel" wicket:attribute="value" /span> > > > > > > So for example we might have a panel that displays the 'top 10 > songs' or > > > the 'top 50 songs' on a music site. The panel is exactly the same in > > > each instance but the markup container that uses that panel can > control > > > how many songs are displayed via specification of an extra parameter > > > ('count' in the following example). > > > > > > Eg., > > > > > > One page could have a lot of space and so decide to show the top 50: > > > > > > <span wicket:id="songChart" wicket:count="50" /span> > > > > > > However another page that is more dense might only have room to > display > > > the top 10 songs > > > > > > <span wicket:id="songChart" wicket:count="10" /span> > > > > > > But in each case the markup and code for the panel itself does not > need > > > to change. > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > > > For additional commands, e-mail: users-h...@wicket.apache.org > > > > > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 8.5.409 / Virus Database: 270.13.82/2351 - Release Date: > 09/07/09 > > 06:40:00 > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > >
