Re: Constraints 2014

For an example of back-off of tied constraints:

{
   "mandatory":  {...
   },
   "optional":  [{
     "aspectRatio":  15/6
     "width": 500
  },  {
      "aspectRatio": 4/3
       "width":  400
   }]
}


On 3/24/2014 10:06 AM, Jan-Ivar Bruaroey wrote:
> On 3/23/14 5:52 PM, Jim Barnett wrote:
>> Assuming that Capabilities and Settings are not controversial, the 
>> main requirements on Constraints that I recall have been the 
>> following (if I've missed any, I'm sure someone will correct me):
>
> Thanks Jim for this summary!
>
>> 1. Clear distinction between mandatory and optional constraints, 
>> namely all mandatory constraints must be satisfied or the error 
>> callback is called.  Optional constraints may or may not be satisfied.
>>
>> 2.  Unknown/unsupported mandatory constraints must fail. (Success 
>> callback means that all constraints are known to be satisfied.)
>>
>> 3.  It must be possible to implement back-off using optional 
>> constraints.
>>
>> 4.  It should be possible to couple constraints, to say, for example: 
>> I prefer an aspectRatio of 15/6 and width of 500.  If I can't have 
>> both of those then give me aspectRatio of 4/3 and width of 400, etc.  
>> (This is an example of both back off and of coupling optional 
>> constraints.)  Mandatory constraints are always coupled because they 
>> all must be satisfied or the api call fails. (I'm putting this as a 
>> 'should', not a 'must' because there wasn't as much discussion/demand 
>> for it, but several people wanted it and no one didn't want it.)
>
> Can you express #4 using constraints please?
>
> .: Jan-Ivar :.
>
>> 5. The application must be notified if changing circumstances result 
>> in previously satisfied mandatory constraints becoming unsatisfied.
>>
>> The lengthiest dispute/discussion was over whether the application 
>> should be notified which mandatory constraints failed.  Some people 
>> felt this made fingerprinting too easy, others felt that information 
>> was important for intelligent applications.   The latter group has 
>> prevailed.
>>
>>
>> On 3/23/14 9:06 AM, Jim Barnett wrote:
>>> +1. The current constraints proposal satisfies a number of 
>>> requirements that we have elaborated in repeated and extensive 
>>> discussions.
>>
>> Would it be useful to re-summarize those exact requirements at this
>> juncture?
>>
>> .: Jan-Ivar :.
>>

-- 
Jim Barnett
Genesys

Received on Monday, 24 March 2014 17:53:09 UTC