ubuntu-phone team mailing list archive

[Thomas Voß <thomas.voss@xxxxxxxxxxxxx>]

On Sat, Jul 20, 2013 at 6:53 PM, Alexander Antimonov
<alexander.antimonov.od.ua@xxxxxxxxx> wrote:
> On Thu, Jul 18, 2013 at 9:37 PM, Thomas Voß <thomas.voss@xxxxxxxxxxxxx> wrote:
>> On Thu, Jul 18, 2013 at 8:28 PM, Michał Sawicz
>>> What if you don't know/care what kind of app should handle, say, a
>>> downloaded PDF file?
>>>
>>
>> Good point and I do agree in general, However, once we allow mime-type
>> handling we break the strict per-app siloing of content.
>>
>> Not sure how to solve that issue for mime-type handling.
>>
>> Thomas
>
> Just some thoughts of how it could be.
>
> An application that wants to spawn another app have to provide
> "spawning mechanism"
> with three parameters: other app's name, MIME-type of a resource, URL
> of the resource.
> Any two of these parameters may be optional but at least one is mandatory.
>
> Spawning mechanism might be: Qt.spawn(...)->Dbus->Upstart or whatever
> is appropriate.
>
> App's name - name of the application to spawn in a form used in the app's
> manifest, like "com.ubuntu.developer.username.myapp". To make not confined apps
> spawnable, Ubuntu will provide manifests for not confined apps too (if
> it doesn't already).

Hmmm, I think applications knowing one another's names and assuming
them to be available will result in tight coupling and introducing
dependencies that we cannot resolve automatically. I would consider it
similar to not relying on an interface to request functionality but
instead relying on one possible implementation  of an interface.

Thomas

> MIME-type and URL - nothing unusual, obvious.
>
> Hierarchy of decision making: name->MIME->URL. URL is considered only when
> neither name nor MIME is provided.
>
> Use cases:
> ${browser} could be any application registered as default handler for
> "text/html"
>
> - spawn a browser with html page as argument, based on MIME-type:
>     name="", MIME="text/html", URL="http://host/page.html";
>
> - spawn a browser with html page as argument, based on URL's "http:" :
>     name="", MIME="", URL="http://host/page.html";
>
> - spawn the browser with fallback to default browser if requested one
> is not installed/registered:
>     name="com.mozilla.firefox", MIME="text/html", URL="http://host/page.html";
>
> - spawn the browser without fallback, if Firefox is not installed
> nothing is spawned:
>     name="com.mozilla.firefox", MIME="", URL="http://host/page.html";
>
> - spawn the browser without an argument:
>     name="com.mozilla.firefox", MIME="", URL=""
>
> - spawn a browser without an argument:
>     name="", MIME="text/html", URL=""
>
> "name" could be not just one app but a list of apps, with
> left-to-right priority:
>     name(s)="com.mozilla.firefox,com.google.chrome"
>
> Also, there is such a thing as Uniform Type Identifier.
> http://en.wikipedia.org/wiki/Uniform_Type_Identifier
>
> You might consider adopting it, in part or as a whole, and use it
> instead of MIME-type.
> Or even instead of name+MIME:
> - spawn a browser with fallback, no need for MIME as parameter anymore:
>     names="com.mozilla.firefox,com.google.chrome,public.html"
> URL="http://host/page.html";