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RE: [indexeddb] IDBRequest.transaction property set to null

From: Israel Hilerio <israelh@microsoft.com>
Date: Wed, 6 Jul 2011 17:27:23 +0000
To: Jeremy Orlow <jorlow@chromium.org>
CC: "public-webapps@w3.org" <public-webapps@w3.org>, Victor Ngo <vicngo@microsoft.com>
Message-ID: <F695AF7AA77CC745A271AD0F61BBC61E3D189396@TK5EX14MBXC119.redmond.corp.microsoft.com>
On Tuesday, June 28, 2011 11:21 AM, Israel Hilerio wrote:
> On Monday, June 27, 2011 11:59 PM, Jeremy Orlow wrote:
> 
> > On Thu, Jun 23, 2011 at 2:21 PM, Israel Hilerio <israelh@microsoft.com>
> wrote:
> >> In the definition of IDBRequest.transaction it stipulates that "This
> >> property can be null for certain requests, such as for request returned from
> IDBFactory.open and IDBDatabase.setVersion."  Based on this we understand
> that the following handlers will set the transaction property to null:
> >> * setVersion onsuccess handler
> >> * setVersion onerror handler
> >> * setVersion onblock handler
> >> * open onsuccess handler
> >> * open onerror handler
> >> Are there any other times when this property should be set to null or is this
> the complete list?  We couldn't think of any other times when this applied but
> wanted to check.
> 
> > I believe this is correct.
> 
> >> Also, in the setVersion case, if we're setting the result property to its active
> transaction, why are we setting the transaction property to null instead of the
> same active transaction?
> 
> > I know Jonas and I talked about this, but I don't remember the
> > reasoning for sure.  One thing I can think of off the top of my head is that
> it's weird that it'd start off null and then be set later.  Also, it would be
> duplicate data given that .result is also set to the transaction.  Is there any
> strong reason to set it?
> 
> > J
> 
> The main reason was to keep a consistent calling pattern inside our event
> handlers:
> * event.target.transaction.oncomplete
> 
> The only exception to this pattern are the open and setVersion APIs.  In the
> case of the setVersion handler we have to use:
> * event.target.result.oncomplete
> 
> It would be nice to use only one pattern all the time.
> 
> Israel
> 

What do you think about the idea of having a consistent/common access pattern for accessing the transaction inside most of our event handlers (i.e. inside setVersion but not open).  This will always guaranteed a good (not null) transaction handler developers can always count on.

Israel
Received on Wednesday, 6 July 2011 17:27:53 GMT

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