Re: The app: URI scheme

On 22/02/13 11:24, John Lyle wrote:
> Hi Marcos, all,
> 
> This is a great proposal, thanks for sharing it.  I have one observation -
> 
> In the app: URI scheme, each instance of an application has a unique authority and therefore a unique origin.  For packaged applications this can isolate and differentiate between two instances of the same application.  For hosted applications, the app: scheme doesn’t apply (at least, that's what I'm assuming).  In this case, if you have multiple instances of the same application, each instance will have the same origin.  This might imply the sharing of data between instances.
> 
> This makes an instance of a packaged and hosted application quite different.  I'm not sure whether this is a problem - there are many differences between a hosted and packaged application - but it might cause some confusion, so I think it would be worth documenting the intention in the system applications execution model in that deliverable.  But this also depends on how instances are dealt with in Firefox OS and Tizen - can you have multiple instances of the same application running?  Is it the same for packaged and hosted apps?  In webinos we support multiple instances.

The Mozilla's proposal of the runtime spec uses the manifest URL to
identify an application. That means you can't install twice an
application that is described by the same manifest URL. And that also
means you can't launch two instances of it.

I think preventing installing twice the same application is a sane
behaviour. We can easily imagine hacks (changing the manifest URL) to
allow an application being installed twice. I do not think this is a
problem.
Regarding running twice the same application, I do not see any advantage
of allowing this and I feel that this is becoming a common pattern (an
application can't have more than one running instance).

It is true that two installed instances of the same hosted applications
would share the same data but this is also true for two websites on the
same origin and will be true for two applications sharing the same
origin. If a user installs "http://example.com/maps/manifest.webapp" and
"http://example.com/reader/manifest.webapp", those applications will be
sharing the same data, *exactly* as they would in a normal web context.

Cheers,
--
Mounir

Received on Monday, 25 February 2013 15:51:26 UTC