Vincent, I like the general direction for conditional displayers and alternate displays. In Curriki/XClams, there are presently two factors that affect the default display. A page is displayed as a learning resource IF it has an AssetClass AND it resides in a spaces starting with "Coll_" (For resource collection space.) Now we have often talked about changing the view based on the role or type of the user, (Student, vs. Teacher vs. Parent, etc.) So how does that factor in? There is certainly room for improvement over the current mish-mash of xpage= and viewer= parameters. Joshua Marks CTO Curriki: The Global Education and Learning Community jmarks(a)curriki.org www.curriki.org -----Original Message----- From: devs-bounces(a)xwiki.org [mailto:devs-bounces@xwiki.org] On Behalf Of Vincent Massol Sent: Sunday, July 22, 2012 8:00 AM To: XWiki Developers Subject: [xwiki-devs] [Proposal] Displayer Architecture for the future Hi devs, I've been thinking about Displayer architecture today and here are my thoughts on how I see them implemented (without entering low-level details): Basics ====== * Everything in XWiki should be a Component and should be able to be implemented in Java and optionally extended in wiki pages (wiki components notion) * Have a Displayer component Role (ie a java interface for displayers) * Have default implementations in the display module for all basic types we want to support (textareas, date, string, number, etc). Basically this means rewriting the current displayers as components. * Allow to register Displayers defined in wiki pages by using wiki components (same mechanism as wiki macros). * Since a lot of Displayers are better written in wiki pages (javascript, css), create a UI submodule of the current display module which contains displayers we want bundled by default in XE (for ex for Dates and Users/Groups) * Extend the current {{display}} macro to support displaying Objects and Object Properties (it already supports passing an EntityType parameter but it's not used ATM). * The {{display}} macro will use the CM to get an instance of a displayer for the Object property type. It'll do by finding the XClass and getting the type from the XClass and then do a getInstance * Add an optional parameter to the {{display}} macro to support passing a displayer hint (by default it would use the "default" displayer for the property type). This will allow some pages to decide which displayer to use to render their content without being forced to use the default displayer. Advanced ========= In order to make it easy for a given class or a given object to decide how to display itself we could also define some special DisplayerBinding XObjects (one per property type). It could work like this: * If the {{display}} macro has the displayer hint specified as parameter then use it * If the {{display}} macro doesn't have the displayer hint specified then check if the xclass document has a DisplayerBinding XObject defined and if so use the displayer pointed to by the binding * If the {{display}} macro doesn't have the displayer hint specified and the xclass document doesn't have a DisplayerBinding XObject defined then check if the object to display have such an XObject and if so use it * Deprecate the notion of "custom displayer" that we have in our XClass since it wouldn't be needed anymore WDYT? I know we're not there yet but it would be cool to make progress on the direction we'd like to take. Thanks -Vincent _______________________________________________ devs mailing list devs(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/devs

2012/7/22 Vincent Massol <vincent(a)massol.net>et>: Currently custom displayers are activate on a per property basis, not by field type, so the binding should be per property. Knowing this it's a bit bizarre to have that binding not being a field of the property of the XClass. It should generally complicated to use bindings instead of just setting a field. There is another need (which I'm working on in the hackathon) to have default custom displayers for ALL property of a specific type for ALL classes. So if we go the component way we should make sure this is also possible. This means a binding at the wiki or multi wiki level for instance. Finally it's also important to have the same displayer system to be supported by calls to $doc.display(). Not everything can be done through macros, so we also need the API to support the same system of displayers In general it's a progress to be able to register new displayers like that as components, but it's important to make it simple to configure. If there are too many indirections it might be hard to actually understand where the configuration actually is. Ludovic -- Ludovic Dubost Founder and CEO Blog: http://blog.ludovic.org/ XWiki: http://www.xwiki.com Skype: ldubost GTalk: ldubost