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Re: [IndexedDB] Passing an empty array to IDBDatabase.transaction

From: Jonas Sicking <jonas@sicking.cc>
Date: Mon, 10 Oct 2011 09:46:22 -0700
Message-ID: <CA+c2ei-PQYK4wEqFzfWg7vNd_WPSbBh0OU2L+OtbVKBgzB+9ig@mail.gmail.com>
To: Israel Hilerio <israelh@microsoft.com>
Cc: Webapps WG <public-webapps@w3.org>
On Fri, Oct 7, 2011 at 11:51 AM, Israel Hilerio <israelh@microsoft.com> wrote:
> On Thursday, October 06, 2011 5:44 PM, Jonas Sicking wrote:
>> Hi All,
>> In both the Firefox and the Chrome implementation you can pass an empty
>> array to IDBDatabase.transaction in order to create a transaction which has
>> a scope that covers all objectStores in the database. I.e. you can do
>> something like:
>> trans = db.transaction([]);
>> trans.objectStore(<any objectstore here>);
>> (Note that this is *not* a dynamic scoped transaction, it's still a static scope
>> that covers the whole database).
>> In other words, these implementations treat the following two lines as
>> equivalent:
>> trans = db.transaction([]);
>> trans = db.transaction(db.objectStoreNames);
>> This, however, is not specified behavior. According to the spec as it is now
>> the transaction should be created with an empty scope.
>> I suspect both Mozilla and Google implemented it this way because we had
>> discussions about this syntax on the list. However apparently this syntax
>> never made it into the spec. I don't recall why.
>> I'm personally not a big fan of this syntax. My concern is that it makes it
>> easier to create a widely scoped transaction which has less ability to run in
>> parallel with other transactions, than to create a transaction with as narrow
>> scope as possible. And passing db.objectStoreNames is always possible.
>> What do people think we should do? Should we add this behavior to the
>> spec? Or are implementations willing to remove it?
>> / Jonas
> Our implementation interprets the empty array as an empty scope.  We allow the transaction to be created but we throw a NOT_FOUND_ERR when trying to access any object stores.
> I vote for not having this behavior :-).

Hi Israel,

I just realized that I might have misinterpreted your response.

Are you saying that you think that passing an empty-array should
produce a transaction with an empty scope (like in IEs implementation
and as described by the spec currently), or a transaction with every
objectStore in scope (like in Firefox and chrome)?

/ Jonas
Received on Monday, 10 October 2011 16:47:21 UTC

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