[xwiki-devs] [Discussion] Defining Sheets

Hi devs, A prerequisite for Application Within Minutes [1] is to be able to specify the sheet that will be used to display a document without touching the content of that document [2]. This can be done in multiple ways, depending on how we define the notion of a sheet. (1) Class sheets vs. document sheets A class sheet displays an object of a particular type and is specified in the definition of that type. This means that when you create or edit a class, i.e. a type of object, you can specify which sheet should be used to display the instances of that class. Pro: Documents don't have to specify a sheet. Con: We have to determine which sheet to use in case there are multiple objects attached to a document. A document sheet displays a document of a particular type and is specified at document level because the document type, unlike the xclass, does not exist actually. The document type is inferred from the type of objects the document has, or from its content, or, why not, from the type of attachments it has. Pro: Doesn't have the class sheet con. Con: Each document has to specify which sheet to use. Class sheets are enough for Application Within Minutes because the wizard will create a single class (with a sheet) and so the application items will have only one object that specifies a sheet. (2) Separate sheets per action? The current practice is to define a single (class) sheet which either checks for the current action in its code or uses doc.display method whose output is action specific. How often did you had the need to write separate sheets per action (e.g. create, view, edit, search, changes)? (3) Which actions require a sheet? If we're talking about class sheets then the list of actions that target an object and which require a sheet is limited. Currently we have "view" and "edit", but Ludovic proposed also "create", "search" and "changes". If we're talking about document sheets then we can have custom actions and so we need an extensible mechanism to map actions to sheets. (4) Sheet parameters? If we're talking about class sheets then they only need to specify how an object is displayed. Document sheets on the other hand may need to control elements like: * which tabs (comments, annotations, attachments, etc.), if any, are displayed * show title field in edit mode * the side panels * the form buttons WDYT? Thanks, Marius [1] http://dev.xwiki.org/xwiki/bin/view/Design/ApplicationWithinMinutes [2] http://dev.xwiki.org/xwiki/bin/view/Design/ApplicationWithinMinutesCoreChan…