Re: Should interfaces with values really be [NoInterfaceObject]?

SVG 1.1 did permit instances of these interfaces and existing UAs support
this (https://bugzilla.mozilla.org/show_bug.cgi?id=1241898#c6).

Currently Firefox does not have either SVGUnitTypes and SVGZoomAndPan as
[NoInterfaceObject].

Robert.

On 22 August 2016 at 06:35, Amelia Bellamy-Royds <
amelia.bellamy.royds@gmail.com> wrote:

> I think the logic for declaring them "No Interface Object" was that there
> are never instances of these interfaces (they are all mix-ins implemented
> by the different element interfaces), so there was no need to clutter up
> the global namespace.
>
> If it is a breaking change that is causing problems in implementations,
> that would be a good argument for implementing them as global objects.  But
> there are likely to be other propblems: the hierarchy of interfaces was
> collapsed in many cases and names were changed.  If tests are detecting the
> individual interface names, instead of the exposed methods and properties
> on the element interfaces, this re-organization becomes a breaking change,
> too.  In contrast, if they are all "No Interface Object" interfaces, then
> the exact names and organization of the mix-in interfaces is safe to
> change, because it's never exposed in the API.
>
> Are you able to generate a full list of interfaces Firefox detects in test
> cases?
>
> ~ABR
>
> On 21 August 2016 at 15:07, Robert Longson <longsonr@gmail.com> wrote:
>
>> SVG 2 has this webidl definition of SVGZoomAndPan
>>
>>
>> [NoInterfaceObject]
>> interface *SVGZoomAndPan* {
>>
>>   // Zoom and Pan Types
>>   const unsigned short SVG_ZOOMANDPAN_UNKNOWN <https://www.w3.org/TR/SVG2/types.html#__svg__SVGZoomAndPan__SVG_ZOOMANDPAN_UNKNOWN> = 0;
>>   const unsigned short SVG_ZOOMANDPAN_DISABLE <https://www.w3.org/TR/SVG2/types.html#__svg__SVGZoomAndPan__SVG_ZOOMANDPAN_DISABLE> = 1;
>>   const unsigned short SVG_ZOOMANDPAN_MAGNIFY <https://www.w3.org/TR/SVG2/types.html#__svg__SVGZoomAndPan__SVG_ZOOMANDPAN_MAGNIFY> = 2;
>>
>>   attribute unsigned short zoomAndPan <https://www.w3.org/TR/SVG2/types.html#__svg__SVGZoomAndPan__zoomAndPan>;
>> };
>>
>> Without the NoInterfaceObject one could write something like
>>
>>    if (element.zoomAndPan == SVGZoomAndPan.SVG_ZOOMANDPAN_DISABLE)
>>
>> While one now has to write it as
>>
>>    if (element.zoomAndPan == SVGSVGElement.SVG_ZOOMANDPAN_DISABLE)
>>
>> The same applies to SVGUnitTypes. Do we mind about keeping backwards
>> compatibility with any existing usages like this. We found when making
>> this change that our own unit tests fail on SVGUnitTypes usage for
>> instance.
>>
>> Robert
>>
>>
>