Re: [IndexedDB] question about description argument of IDBFactory::open()

On Mon, Aug 9, 2010 at 11:15 PM, Andrei Popescu <andreip@google.com> wrote:

> On Mon, Aug 9, 2010 at 9:57 PM, Jeremy Orlow <jorlow@chromium.org> wrote:
> > I'm pretty sure opening a database with a different description is
> actually
> > already specified: the new one takes precedent.  Take a look at the
> > algorithm for database opening; I'm pretty sure it's there.
> > When talking to Andrei earlier tonight I thought we'd probably want to
> make
> > it optional, but now I'm thinking maybe we shouldn't.  You're right,
> Shawn,
> > that the description can be useful for many reasons.  And although it
> seems
> > redundant for a developer to pass in the description every time, I
> actually
> > can't think of any reason why a developer wouldn't want to.
>
> Actually, I think it's pretty inconvenient to have to specify a
> description every time, especially since I am not sure developers
> would want to change the description very often. I think we should
> allow a null string for future connections as Shawn suggested.
>

How do developers distinguish between when they're opening a database for
the first time or not?  Normally they'd look at the version, but that's not
available until _after_ you've supplied the description (and presumably some
UAs might have asked the user if it's OK or something like that).  If the
spec has a way to enumerate databases (something we've talked about doing)
then it's possible that the developer could decide whether or not to pass in
a version string that way.  But why would they do this?

So the only possible reason I could see for someone doing this is if they
open a database in several places in one page and they can
somehow guarantee that one of them happens first.  The first question here
would be "but why?".  And the second question is whether we trust users to
for sure know the ordering that things are opened.

On the other hand, it doesn't seem that hard to supply a description every
time it's opened.  I mean you just define it in one places within your
script and use that.  Or, better yet, just save the database to a variable
and call open once early on in initialization.  That'll make things less
async anyway.

Am I missing something here?

J