Vincent Massol wrote: 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.

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.

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

Very good! :) Some small comments: * Not sure why you call the class HelloWorldContextualizer instead of HelloWorldVelocityContextInitializer

* 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. * "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: _______________________________________________ devs mailing list devs(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/devs