Re: [xwiki-devs] [VOTE] Object properties references (was [proposal][discussion])

On 01/18/2010 05:54 PM, Anca Luca wrote: Actually on second thought, if we want always parsable references, we need to also find out how to resolve a string with no ^ and/or # separators as Object, respective Property.

A 'current' resolver could resolve "FooBar" as: - currentDocRef^FooBar when of type object (the object (as per ii, iii or iv) of type FooBar in the current document, as resolved by the CurrentStringDocumentReferenceResolver resolver) - currentDocRef^currentDocRef#FooBar when of type property (the property FooBar in the current document (as resolved by the CurrentStringDocumentReferenceResolver resolver), of the object (as per ii, iii or iv) of the class defined by the document reference) In similar manner, a 'default' resolver could resolve "FooBar" as: - defaultDocRef^FooBar when of type object - defaultDocRef^defaultClass#FooBar when of type property (where defaultClass is either defaultDocRef (see above) or a different class, which we agree to be the default) Also, a string like wiki:Space.Page#prop parsed as object would have to be interpreted as 'FooBar' above, and parsed as property, would have the property specified as "prop" of the object obtained by parsing 'wiki:Space.Page" as 'FooBar' above. WDYT? (I hope I didn't mess it up, I know it's complicated, but it has to make sense.) Actually, if we add new types for this, then we still have to find a way to interpret wiki:Space.Page^className as Object or Property (since everything has to make sense as everything), which brigs us in a bit of a loop. If considering as invalid is harder than parsing, I go for this one: +1 Thanks, Anca >> >>> iv) a shortcut for wiki:Space.Page^className[0] (which, note, does not >>> necessarily mean the first object in that document, since indexing of objs in a >>> document is not recomputed when objects are deleted). >> >> What is the reason? So that object names don't move when objects are added/removed? > > yes, because they are identified by their index. > >> >> I don't know enough but +0 for iii) or iv). >> >> Thanks >> -Vincent >> >>> WDYT? >>> >>> Thanks, >>> Anca >>> >>> On 01/13/2010 02:42 PM, Anca Luca wrote: >>>> Hi devs, >>>> >>>> Short story: >>>> 1/ add the CLASS, OBJECT, PROPERTY EntityTypes in the model >>>> >>>> +1 >>>> >>>> 2/ serialization for referencing a property of an object >>>> a) wiki:Space.Page^className[objectNumber]#property >>>> b) wiki:Space.Page^className#objectNumber$property >>>> +0.75 for b) >>>> >>>> Long story: >>>> >>>> 1/ I would need to extend the EntityReference to be able to target a >>>> property in an object in a document. >>>> For this, I will need to add >>>> >>>> /** >>>> * Represents a Class Entity >>>> */ >>>> CLASS, >>>> >>>> /** >>>> * Represents an Object Entity. >>>> */ >>>> OBJECT, >>>> >>>> /** >>>> * Represents a Property Entity >>>> */ >>>> PROPERTY, >>>> >>>> in the EntityType. Although I would prefer an extensible framework that >>>> would allow to extend the possible entity types without changing an enum >>>> in the platform (for any API user to be able to define its own >>>> references), I think this is fairly extensible (these are key concepts >>>> in the xwiki model and I don't think they would be changed that soon, >>>> and their interpretation is flexible, they could be combined with any >>>> parent to generate either references to class definitions or instances). >>>> here's my +1 for this. >>>> >>>> 2/ I would also need a 'standard' string serialization for these. Now, >>>> there's also the option to do it in my own module (annotations) because >>>> only I need it ftm, but I prefer to have a platform wide approach. Opinions? >>>> There are 2 choices, with a potentially different combination of separators: >>>> >>>> a/ wiki:Space.Page^className[objectNumber]#property >>>> >>>> pros: it's a suggestive way to access objects by number ([] is the >>>> standard syntax for array indexed access and the objects are accessed by >>>> index), [] is supported by JCR so maybe we should support it too >>>> cons: [] is somewhat inconsistent with all other separators which are >>>> just one separator, to the left (right) of the entity, harder to >>>> implement the [] separators on the current framework >>>> >>>> b/ wiki:Space.Page^className#objectNumber$property >>>> >>>> pros: inline with the separator usage we already have (and easier to >>>> implement for this reason), could be easier refactored to contain an >>>> object name instead of the number >>>> cons: $ separator can collide with velocity syntax (can potentially >>>> cause trouble when used in velocity -- an alternative could be the pipe >>>> |), could be harder to drop the object number part of the reference to >>>> refer a property in a class (if wanted, in the future) >>>> >>>> I have no other argument between a) and b) but the implementation speed >>>> one, so I'd go for a b)-like approach, in the spirit of the current >>>> separators. >>>> >>>> WDYT? >>>> >>>> Thanks, >>>> Anca