Re: [webcomponents]: Declarative Custom Elements Take Umpteen, The Karate Kid Edition

That's clever.


On Tue, May 14, 2013 at 3:38 PM, Robert Ginda <rginda@chromium.org> wrote:

> On Tue, May 14, 2013 at 2:31 PM, Scott Miles <sjmiles@google.com> wrote:
>
>> And to be clear, we also have to be able to do this (not that anybody
>> said anything to the contrary)
>>
>> <element ...>
>>   <script src="..."></script>
>> </element>
>>
>> If there is more than once <script>, I assume the last one 'wins'?
>>
>>
> If that's the case then authors could end each component with
> <script>MyComponentClass</script>, setting the final completion value
> without forcing extra parens or a looks-like-a-noop-but-isn't expression
> (a-la Perl) at the end of the component source.
>
>
>> On Tue, May 14, 2013 at 2:30 PM, Scott Miles <sjmiles@google.com> wrote:
>>
>>> So, I don't love the extra punctuation, but there are other good things
>>> here. We do away with duplication of tag name and the magic
>>> [something].register call.
>>>
>>> Presumably I can still set up private members in a closure, like this
>>> (?):
>>>
>>> <script>
>>>   var privateStack = [];
>>>   (class XFoo: HTMLElement { readyCallback() { privateStack.push(...); }
>>> });
>>> </script>
>>>
>>> The last critical bit is some way to access our <element>. We could have
>>> another callback which is essentially a static, called once per <element>
>>> to allow access to the <element> itself, but I don't know where we'd put it
>>> other than on the prototype itself.
>>>
>>> Scott
>>>
>>>
>>>
>>> On Tue, May 14, 2013 at 2:09 PM, Elliott Sprehn <esprehn@gmail.com>wrote:
>>>
>>>>
>>>>
>>>>
>>>> On Tue, May 14, 2013 at 2:04 PM, Daniel Buchner <daniel@mozilla.com>wrote:
>>>>
>>>>>
>>>>> On Tue, May 14, 2013 at 1:58 PM, Erik Arvidsson <arv@chromium.org>wrote:
>>>>>
>>>>>>
>>>>>> <element name="foo-bar">
>>>>>>    ...
>>>>>>    <script>
>>>>>>        class FooBar {
>>>>>>            ...
>>>>>>        };
>>>>>>    </script>
>>>>>> </element>
>>>>>
>>>>>
>>>>> Is it then possible to explicitly return the class after definition?
>>>>> I'm asking because <script> return value is something I was not aware of.
>>>>>
>>>>
>>>> Yes, by wrapping it in parenthesis. The spec
>>>> http://people.mozilla.org/~jorendorff/es6-draft.html#sec-13.5 seems to
>>>> say that (class X { }) returns X but class X { } at the top level returns
>>>> undefined.
>>>>
>>>> Thankfully it's not too gross, you'd just have:
>>>>
>>>> <script>
>>>> (class MyCustomWidget : HTMLElement {
>>>>   // ...
>>>> })
>>>> </script>
>>>>
>>>> ...   ...
>>>>>    <script>
>>>>>        class FooBar {
>>>>>            ...
>>>>>        };
>>>>>
>>>>>        return FooBar;
>>>>>
>>>>>
>>>>>
>>>> "return" isn't valid in the top level execution block which sucks. It
>>>> would nice if we relaxed that restriction and allowed a return up there.
>>>>
>>>> - E
>>>>
>>>>
>>>
>>
>