Re: [wildfly-dev] Management model attribute groups

Forgot to hit "reply to list" on this one. On 12/10/2014 10:30 AM, Brian Stansberry wrote: > On 12/10/14, 10:06 AM, David M. Lloyd wrote: >> On 12/10/2014 09:52 AM, Brian Stansberry wrote: >>> On 12/10/14, 9:22 AM, Kabir Khan wrote: >>>> >>>>> On 9 Dec 2014, at 21:00, Brian Stansberry <brian.stansberry(a)redhat.com&gt; wrote: >>>>> >>>>> Off and on we've had discussions around the idea of "attribute groups". >>>>> We've got some use cases that are crying out for such a thing[1], so I'd >>>>> like to propose doing something concrete but simple for these for WF 9, >>>>> ideally in the next month. >>>>> >>>>> A big part of my goal here is to ensure that whatever we do doesn't >>>>> preclude something more advanced in any next generation management >>>>> stuff, e.g. David's stuff. >>>>> >>>>> PART I Concepts >>>>> >>>>> 1) What is an attribute group? >>>>> >>>>> The "attribute group" concept I propose is simply a collection of >>>>> attributes associated with the same resource type that are independently >>>>> configurable but are statically declared to be conceptually related. The >>>>> group has a name, and members. The name provides a brief indication of >>>>> the nature of the relationship. >>>>> >>>>> The goal is to provide information to the user to help them better >>>>> understand the relationship between attributes. In particular, >>>>> management tools could use this information to visually present related >>>>> attributes together, e.g. in a tab or other grouping widget in the web >>>>> console. >>>>> >>>>> 2) What isn't an attribute group? >>>>> >>>>> Something relevant to writes. >>>>> >>>>> 3) Why would I use a child resource instead of an attribute group? >>>>> >>>>> Because the attributes control a discrete piece of functionality and you >>>>> need to be able to turn that on or off as a unit. So you add/remove the >>>>> resource. >>>>> >>>>> 4) Why would I use a complex attribute with a bunch of fields instead of >>>>> n>1 simple attributes in a group. >>>>> >>>>> a) Because the attributes control a discrete piece of functionality and >>>>> you need to be able to turn that off as a unit. So users can undefine >>>>> the complex attribute. >>>>> >>>>> b) Because it's a common use case that modifications to n>1 of the >>>>> fields should be done atomically and you don't want to force users to >>>>> use a CLI batch. So you let them use write-attribute and specify the >>>>> value of all the fields. >>>> Why not something along the lines of :write-attribute-group(name=mygroup, value={attr1=a, attr2=b})? >>>> Internally that could create a composite for us, giving complex attribute functionality while avoiding the messy resource descriptions >>>> >>> >>> On the branch of the thread where I'm discussing with Tomaz, he raised >>> the same idea, which I think is a good one. I think a "write-attributes" >>> with no relationship to attribute-group makes more sense though. >> >> I agree. I have always felt that we should allow more than level of >> grouping. > > Did you mean "should NOT allow"? No, I mean multiple levels _should_ be allowed, just with multiple qualifiers. Multiple attribute writing per resource _should_ be allowed regardless of the depth or mixture of nesting. I.e. I should be able to do something like :write-attributes({"foo" = 123, "bar.baz.zap" = "hello"}) as one operation, with no special regard necessary to deal with attribute group navigation.