Hi, My ideas:
1) A component can implement a sub-interface of IAjaxListener (as seen in the wicket source already) it tells it's support AJAX 2) after an IAjaxListener sub interface method is invoked, changes to components are collected in a delegate 3) after the invoke all components on page are traversed (being called on renderAjaxComponent method) and it returns it's changes since last rendering as javascript statements (so there is an ajax render cycle) 4) those javascript statements are generated with help from a javascript(dialect) class which returns browser dependent javascript 5) changes are sent back to client where they gets executed with eval(...) benefits: 1) server knows components states on client 2) all changes to different components are seen and returned at once 3) standarized way by which changes over multiple components are returned 4) ajax is completly invisible for wicket developer, it powerfull yet free 5) auto fallback on normal wicket behavior if ajax is not supported by browser --------------implementation details: needed in wicket Component class: 1) delegate to changes-collector implentation 2) renderAjaxComponent method which requests javascript change statments from delegate and provides hook for developer to add its own javascript statements (for example calls to javascript he included in page) 3) javascript id (from html markup or generated one) to be used by delegate needed in wicket lib: 1) javascript changes generator lib 2) browser detection with dialect sub classes from generator lib to handle differences BTW we should not call the ajax delegate "ajaxrenderer"... Regards Jan Blok > Hi, > > this is what we should have as soon as possible if i am tasting the area > here around JavaOne. > > What i call ajax rendering is this, a component knows his state (much > more then it did now!!) and if > he sees a change in his request he will print this out as a javascript > statement that will be send to the browser > and executed with eval() > I will get this javascript of the ajax enabled components on a ajax > request after dispatching to the listener first. > (just like a normal doRender after a component listener call) > > So what we don't think we want is subclasses every component that we > have now to get ajax rendering on it. > Because then if you want to use a component that you want to tweak or > implement like a link you have to subclass > 2 components the normal one or the ajax enabled one.. So you have to > choose at that time what you want.. > > What we could do is add 3 methods to Component: > > 1> final public setAjaxRendering(boolean) > 2> non final protected createAjaxRenderer() returns a instanceof a yet > to make interface IAjaxRenderer > 3> final public getAjaxRenderer() returns the instance that was made by > 2 or null.. > > that interface can or will have the following methods: > > render() The render method that is called when it should render itself > through an ajax call > setCssId(String) // this is really needed because if the component > doesn't have a css id then ajax rendering will be disabled > setVisible(boolean) // component.setVisible() will redirect its boolean > to this object if it has ajax rendering because the component must > render itself, but be made non visible at the client side.. > setModelValue(Object value) // ajax rendering will cost more. Because we > have to track changes so that we can generate the right javascript > statements on the server to send to the client. > setStyleClass(String) the style it should use (for example an TextField > could have a normal style and a error style (field turns red)) > > And i think there will be a lot more set methods for all kind of > properties. We just have to figure out how for we want to go.. > > > Component should bne altered a bit: > > by it rendering (real rendering) it should look for its Tag's attribute > map and set the cssid to the above implementation of the IAjaxRender > because > the css tag is specified in the html (maybe we should be able to > generate or alter them if css tags are in a listview/repeating components) > > als the setVisible method should test for the ajaxrenderer and if it is > there it shouldn't set its own visibililty flag but redirect that to the > ajaxrenderer > So that the component will render itself (and then set though some css > class or javascript to non visible) so that we can alter its state > afterwards > (set it visible, set its value) > > > So when this is in place this happens if a ajax call is coming in: > > the event is dispatched. > then all the components are visited and if they have a ajaxrenderer call > render on it. > the components checks if he has changes that he should set to the > browser (like the model value: document.getElementById(cssid).value = > xxxx) > what all the components did return is send to the client and with a > simple javascript eval evaluted and everything is updated. > > 2 things to look for: > > 1> we must have a javascript generating class that generate above pieces > of code (i already had some prototype checked in) > 2> for example that value =xxxx a few lines above... that xxxx what is > that? Normally the value could go through converters/formatters etc. > And how do we get the model object there. how to really test for a > change..... > > any comments? > > johan > > > > > ------------------------------------------------------- > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > from IBM. Find simple to follow Roadmaps, straightforward articles, > informative Webcasts and more! Get everything you need to get up to > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > _______________________________________________ > Wicket-develop mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/wicket-develop > ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! 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