Re: Notification event handlers

I don't think this is an issue, since JS event handlers don't fire until
you've re-entered the event loop.


On Mon, Jun 10, 2013 at 7:16 PM, Justin DeWitt <dewittj@google.com> wrote:

> Hi,
>
> In continuing to read the spec, I came across the example in Section
> 6.1[1] where the notification is created using the constructor and then
> event handlers are attached in the next few lines.  Doesn't this introduce
> a race between the JS context and the user agent?  I could imagine this
> causing an issue if the notification were shown immediately, since the
> "show" event could fire before the "onshow" event handler was attached.
>
> Can we update the constructor to accept the various event handlers in the
> options dictionary?  I suppose it would be something like updating the API
> section [2] to include the following text (steps 9-12 are new):
>
> The Notification(title, options) constructor must run these steps:
>
>    1. Let notification be a new notification<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#concept-notification> represented
>    by a Notification<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#notification>
>     object.
>    2. Set notification's title<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#title>
>     to title.
>    3. Set notification's direction<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#direction>
>     to options's dir.
>    4. If options's lang is a valid BCP 47 language tag, or the empty
>    string, set notification's language<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#language>
>     to options's lang, or set it to the empty string otherwise. [LANG]<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#refsLANG>
>    5. Set notifications's origin<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#origin> to
>    the current origin<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#origin>
>    .
>    6. If options's body is present, set notification's body<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#body>
>     to body.
>    7. If options's tag is present, set notification's tag<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#tag>
>     to tag.
>    8. If options's icon is present, resolve<http://www.whatwg.org/specs/web-apps/current-work/multipage/urls.html#resolve-a-url>
>     icon against the entry script<http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#entry-script>
>    's base URL<http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#script's-base-url>,
>    and if that does not fail, set notification's icon URL<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#icon-url> to
>    the resulting absolute URL<http://www.whatwg.org/specs/web-apps/current-work/multipage/urls.html#absolute-url>.
>    (Otherwise icon URL<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#icon-url> is
>    not set.)
>    9. If *options*'s onshow is present, set *notification*'s onshow<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#handler-onshow>handler to
>    onshow.
>    10. If *options*'s onclose is present, set *notification*'s onclose<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#handler-onclose>handler to
>    onclose.
>    11. If *options*'s onerror is present, set *notification*'s onerror<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#handler-onerror>handler to
>    onerror.
>    12. If *options*'s onclick is present, set *notification*'s onclick<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#handler-onclick>handler to
>    onclick.
>    13. Return notification, but continue running these steps
>    asynchronouusly.
>    14. If the notification platform supports icons, the user agent may
>    start fetching<http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#fetch>
>     notification's icon URL<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#icon-url> at
>    this point, if icon URL<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#icon-url> is
>    set.
>    15. Run the show steps<https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#show-steps>
>     for notification.
>
>
> Alternately, there could be a handlers object in *options* that contains
> all the event handlers.
>
> Justin
>
> [1]
> https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#using-events
> [2] https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.html#api
>