Hi, On Tue, Jan 8, 2019 at 11:08 PM Jason E Bailey <jason.bai...@24601.org> wrote:
> I really appreciate the thought that you put into this. > > If you are utilizing the JCR Resource Provider to store a resource you > have to declare a jcr:primaryType, and you are then bound by the definition > of the node as to what you can add as an attribute or a child type. So > there is such thing as "creating a resource without a JCR node type" if > that resource is to be persisted in the JCR. > You can simply use nt:unstructured or any other node type, but what I meant was that you don't drive your type using JCR node type. Maybe you want to use sling:resourceType exclusively. For example if you have an existing content like this: ``` + /mycontent - jcr:primaryNodeType = "nt:folder" - jcr:created = "2019-01-01T00:00:00Z" ``` Here, since it is using [nt:folder], you may decide to define a DataModel for nt:folder by defining jcr:created property for it (Note the property is actually from the supertype [nt:hierarchyNode]). So when other code inspect the resource (/mycontent) using DataModel, it will get Property instance for jcr:created. But you don't have to strictly model your content using JCR like this. Like I said, you can simply decide to drive the typing using resource type only: ``` + /mycontent2 - jcr:primaryNodeType = "nt:unstructured" - sling:resourceType = "my/page" - my:created = "2019-01-01T00:00:00Z" - my:title = "Title 1" ``` Here, you simply define a DataModel for `/apps/my/page` having my:created and my:title properties. So when other code inspect the resource (/mycontent2) using DataModel, it will get Property instances for my:created and my:title. Cheers, Christanto [nt:folder] https://wiki.apache.org/jackrabbit/nt%3Afolder [nt:hierarchyNode] https://wiki.apache.org/jackrabbit/nt%3AhierarchyNode > > One of the core tenants of Sling is that everything is a Resource. One of > my expectations of a Type system is that I can create a type by POST and > retrieve the structure of the type via a GET. That the definitions of a > Type are themselves resources. > > I may be missing this from your whitepaper, is that doable? > > -- > Jason > > On Tue, Jan 8, 2019, at 9:11 AM, Christanto Leonardo wrote: > > Hi, > > > > > 5. you describe it should be possible to derive data models from JCR > CND > > definitions. do you think this should be the major use case? JCR CND > > definitions are quite out-of-fashion nowadays, and used more for > historical > > reasons (or for performance optimizations because oak indexes are based > on > > them). the tooling around them is not good (e.g. difficult to > > update/replace them in a running system). > > > > The purpose of the Sling Modeling Framework is to model your > applications, > > possibly the existing ones. > > So if you have an existing resource defined in JCR with all the node > types > > (e.g. cq:PageContent resource), the modeling framework must be able to > > model that. > > If you create a new resource without JCR node type, then when defining > that > > resource type you don't need to use CND. > > > > I think it is already explained at: > > > > 1. > > > > > https://github.com/christanto/sling-whiteboard/blob/master/modeling/docs/explainer.md#data-modeling-using-jcr-node-types > > 2. > > > > > https://github.com/christanto/sling-whiteboard/blob/master/modeling/docs/explainer.md#modeling-the-underlying-platforms-typing-system > > > > Cheers, > > Christanto > > > > > > On Tue, Jan 8, 2019 at 6:44 PM Stefan Seifert <sseif...@pro-vision.de> > > wrote: > > > > > hello christanto. > > > > > > thanks for bringing this up! some first questions after a first read: > > > > > > 1. why defining a new "DSL" to describe the model metadata? what's with > > > existing things like json schema. defining a completely new DSL often > has > > > the risk of not getting it "right" in the first place. > > > > > > 2. do you plan to support only a single resource/node and it's > properties. > > > what's with sub tree structures, that are supported by JCR CND > definitions? > > > more complex data models like forms are unlikely to be represented by a > > > single resource. or maybe that is already covered with the property > > > handlers although the name does not indicate it. > > > > > > 3. one of the reasons why sling is why it is (without an explicit > modeling > > > capability) is the rule #1 of david's model "Data First, Structure > Later. > > > Maybe." [1]. this was stated a very long time ago. would be nice if > you can > > > add a reference to your explainer page to it as well and explain why > you > > > think different nowadays (i think there are good reasons for it, but it > > > always depends on the use cases). > > > > > > 4. the name "Models" can be mixed up with "Sling Models" [2] which > points > > > somewhat into the same direction but is currently based on different > > > concepts and is already used much. but i suppose this can be sorted out > > > later to decide if this new approach can be "Sling Models 2.0" or the > new > > > things should get a different name (like Type System). still it would > make > > > sense to also add a reference to sling models to the explainer. > > > > > > 5. you describe it should be possible to derive data models from JCR > CND > > > definitions. do you think this should be the major use case? JCR CND > > > definitions are quite out-of-fashion nowadays, and used more for > historical > > > reasons (or for performance optimizations because oak indexes are > based on > > > them). the tooling around them is not good (e.g. difficult to > > > update/replace them in a running system). > > > > > > 6. you describe some "other models" like FormModel, ActionsModel which > > > sound like hypermedia support. i do not fully understand how hypermedia > > > support fits into the other parts you describe which primarily > describe the > > > data model and not the actions for them. where does this hypermedia > > > metadata come from? > > > > > > stefan > > > > > > [1] https://wiki.apache.org/jackrabbit/DavidsModel > > > [2] https://sling.apache.org/documentation/bundles/models.html > > > > > > > > > > > > >-----Original Message----- > > > >From: Christanto Leonardo [mailto:christanto.leona...@gmail.com] > > > >Sent: Tuesday, January 8, 2019 4:03 AM > > > >To: dev@sling.apache.org > > > >Subject: Re: Sling Type System: started a wiki page for concepts, > ideas, > > > >motivation > > > > > > > >Hello, > > > > > > > >I am currently working on the proposal to introduce the concept of > > > modeling > > > >in Sling. See it at < > > > >https://github.com/christanto/sling-whiteboard/tree/master/modeling>. > > > >One is especially encouraged to read the explainer at < > > > >https://github.com/christanto/sling- > > > >whiteboard/blob/master/modeling/docs/explainer.md > > > >>. > > > > > > > >My hope is that the Sling Modeling Framework can provide the ability > to > > > >model many concepts in the application, starting with the typing > system of > > > >the resource (i.e. the resource type definition) as the lowest layer. > > > > > > > >Please let me know what you think. I plan to continue developing this > > > >proposal. > > > > > > > >Cheers, > > > >Christanto > > > > > > > >On 2018/10/02 11:59:08, Bertrand Delacretaz <b...@apache.org> wrote: > > > >> Hi,> > > > >> > > > >> Recent discussions with a number of people from the Sling community> > > > >> [1] have helped clarify my thoughts about this, I have started a > wiki> > > > >> page at > > > > > > > > https://cwiki.apache.org/confluence/display/SLING/Sling+Type+System%3A+moti > > > >vation+and+requirements> > > > > > > > >> and feedback is welcome, on that page or here.> > > > >> > > > >> Roughly, the goal is to create a Sling Type System that defines > much> > > > >> more precisely what the various Resource Types can contain, how > they> > > > >> work together, etc. with the goal of generating self-describing> > > > >> interfaces.> > > > >> > > > >> Let's see where this leads, it's just rough ideas so far but it > feels> > > > >> like a useful unifying concept for Sling.> > > > >> > > > >> -Bertrand> > > > >> > > > >> [1] along with reading "a conversation with Alan Kay, creator of> > > > >> Smalltalk" - https://queue.acm.org/detail.cfm?id=1039523> > > > >> > > > > > >
