Vincent Massol wrote: > On Sep 30, 2008, at 9:22 AM, Anca Paula Luca wrote: > >> >> Vincent Massol wrote: >>> Very good! :) >>> >>> Some small comments: >>> >>> * Not sure why you call the class HelloWorldContextualizer instead of >>> HelloWorldVelocityContextInitializer >> Just for a shorter name and because that component does not actually >> initialize >> velocity context, it just uses that to get access to the >> VelocityContext. So its >> semantic is not that of initializing velo context but of >> contextualizing the >> HelloWorld. Happily enough, this hijack method won't last. >> If you think we really must, I can change it. > > The main reason for my comment is that the notion of Context and > Contextualizer exists in component based programming and in plexus and > it's something different. For example we could have added a > Contextualizer interface with a single method: > > contextualize(ExecutionContext context); > > It's not very important but my fear is that readers will use your > example when they write code and would lead to badly named classes.
They most probably will. Will change. > BTW I see you've used that in Watch components so that should be > modified too IMO. > >>> * Might be good to have a small section about the fact that >>> components >>> remove the need for static code (for the best!) since you can have a >>> component with a "singleton" lifecycle. >> Maybe we should have a better section about the <instantiation- >> strategy> and >> what can be done with it, because eliminating the static code is not >> the >> components' main benefit and I'd like to keep the tutorial to "what >> you really >> really need to know" stage, with links for further info. > > > Thanks > -Vincent > > >> The rest should be for Sergiu's expertise since he's the one that >> contributed >> those last three paragraphs. >> >>> * "and since we don't want to add the whole core and all its >>> dependencies as a dependency of a simple lightweight component, ". >>> Actually the real problem is that this would create a circular >>> dependency since the core uses the components. >>> * "In the component world, the current request information is held in >>> an execution context. This is actually more powerful than the old >>> XWiki context, as it is a generic execution context, and you can >>> create one anytime you want and use it anyway you want. And you don't >>> have to manually pass it around with all method calls, as execution >>> contexts are managed by the Execution component, which you can use >>> just like any other XWiki component.". We need to specify that it's a >>> ThreadLocal implementation (meaning you get a new instance of the >>> Execution context per thread). This means also that it's initialized >>> by default at all XWiki entry points (i.e. where threads are created: >>> Servlet, Portlet, Lucene thread, Stats thread, etc). >>> * "If you need some functionality from the old core, consider >>> rewriting that part as a new component first, and then use that new >>> component from your code.". I'd rather ask to discuss it on the list >>> so that we find a solution collaboratively >>> >>> I even learnt something! Good idea with the old xwikicontext cast >>> to a >>> Map, hasn't thought of that :) >>> >>> Excellent work Anca. >>> >>> Big +1 to link it from our dev practices document. >>> >>> Thanks >>> -Vincent >>> >>> On Sep 29, 2008, at 8:33 PM, Anca Paula Luca wrote: >>> >>>> Hi devs, >>>> >>>> while developing my XWiki watch component, I've written a quick >>>> start tutorial >>>> on XWiki components, which I would like to add in the dedicated >>>> section on >>>> platform.xwiki.org. >>>> >>>> It is currently in draft version at >>>> http://dev.xwiki.org/xwiki/bin/view/Drafts/CreatingComponents . >>>> Please give it a >>>> critical look and signal any errors that might have slipped or send >>>> improvement >>>> suggestions. >>>> >>>> Here's my +1 for taking it out of draft version, WDYT? >>>> >>>> Happy coding, >>>> Anca Luca > _______________________________________________ > devs mailing list > [email protected] > http://lists.xwiki.org/mailman/listinfo/devs _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
