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Re: [Bug 11398] New: [IndexedDB] Methods that take multiple optional parameters should instead take an options object

From: Jeremy Orlow <jorlow@chromium.org>
Date: Tue, 14 Dec 2010 11:44:16 +0000
Message-ID: <AANLkTi=97oQGRwAxhgnhqetRdFpOiMi2UW5NgwmXEQvU@mail.gmail.com>
To: Jonas Sicking <jonas@sicking.cc>, public-webapps WG <public-webapps@w3.org>
Oops.  + list again.

On Mon, Dec 13, 2010 at 6:35 PM, Jeremy Orlow <jorlow@chromium.org> wrote:

> On Sat, Dec 11, 2010 at 1:20 AM, Jonas Sicking <jonas@sicking.cc> wrote:
>
>> On Fri, Dec 10, 2010 at 7:27 AM, Jeremy Orlow <jorlow@chromium.org>
>> wrote:
>> >
>> > In addition to createObjectStore, I also intend to convert the following
>> > over:
>> >
>> > IDBObjectStore.createIndex
>>
>> Sounds good.
>>
>> > IDBObjectStore.openCursor
>> > IDBIndex.openCursor
>> > IDBIndex.openKeyCursor
>>
>> I'm not convinced about these. It seems that this on average creates
>> more syntax for authors rather than less. I see the main advantage
>> with the options objects when you have so many arguments that it's
>> hard to know which is which. Or when so many are optional that you end
>> up having to specify the default value for a bunch just to specify the
>> one you want to. In both cases these are of course fairly fuzzy
>> limits. But it doesn't seem like either really applies here.
>>
>> I chatted with Brendan Eich about this and he made a good point. Do we
>> know if all combinations are really going to be common? I.e. are all
>> of the following going to be common:
>>
>> openCursor();
>> openCursor(range);
>> openCursor(range, dir);
>> openCursor(null, dir);
>>
>> If not, could we order the two optional arguments such that it's rare
>> to need to specify the second, but not the first?
>>
>
> My biggest concern is about the future, if we add more params.
>
> If we're not worrying at all about the future, then I'd probably agree that
> as is is best (since a cursor over everything backwards probably isn't super
> common).
>
>
>> > IDBKeyRange.bound
>>
>> On this one I feel rather strongly that option objects is overkill.
>> Not only is it fairly clear what the arguments mean since they
>> pair-wise match up to the two required arguments. I could even go with
>> the following signature:
>>
>> IDBKeyRange bound(
>>  in any lower,
>>  in any upper,
>>  in optional boolean lowerOpen,
>>  in boolean upperOpen);
>>
>> That way you have to specify open-ness for both if you want to specify
>> it for either.
>>
>
> I didn't realize that was valid IDL and that's what it meant!  Sure, you're
> probably right this is overkill.  Requiring that they be in pairs or not be
> there at all seems reasonable.
>
>
>> > We did all of these two weeks ago in Chromium and have gotten some
>> feedback.
>> >  The main downside is that typos are silently ignored by JavaScript.  We
>> > considered throwing if someone passed in an option we didn't recognize,
>> but
>> > this would make it impossible to add more options later (which is one of
>> the
>> > main reasons for doing this change).  I think what we might do is just
>> log
>> > something in the console with this happens.  (Should the spec actually
>> make
>> > a recommendation to this effect?)  Besides that, I think overall we're
>> happy
>> > with the change.
>>
>> I'm with Pablo here. It seems unlikely that we'd introduce an argument
>> in the future which we'd want old implementations to just silently
>> ignore. For example, if we add 'required' as a boolean argument to
>> createIndex in v2, I'd think we'd want an implementation which doesn't
>> support that to throw. Similarly, if we add 'expression' as a way to
>> solve bug 10000, we'd want a v1 implementation to throw, no?
>>
>
> You're probably right, but how should we tell people to detect whether
> certain implementations support certain features?  (Try/catches?  That seems
> pretty ugly.)
>
>
>> > Lastly, are we happy with all the variable names for the above functions
>> > being directly turned into parameter names for the options object?  If
>> not,
>> > please enumerate any changes you think we should do.
>>
>> Sounds good to me.
>>
>> / Jonas
>>
>
>
Received on Tuesday, 14 December 2010 11:45:06 GMT

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