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Re: [Bug 11257] New: Should IDBCursor.update be able to create a new entry?

From: Jeremy Orlow <jorlow@chromium.org>
Date: Fri, 12 Nov 2010 08:12:38 +0300
Message-ID: <AANLkTi=kTL3PAFVTo9CVGViwnkksxGXcwbrB0kWrqSvF@mail.gmail.com>
To: Jonas Sicking <jonas@sicking.cc>
Cc: public-webapps@w3.org
On Fri, Nov 12, 2010 at 12:11 AM, Jonas Sicking <jonas@sicking.cc> wrote:

> On Thu, Nov 11, 2010 at 11:51 AM, Jeremy Orlow <jorlow@chromium.org>
> wrote:
> > On Thu, Nov 11, 2010 at 8:46 PM, Jonas Sicking <jonas@sicking.cc> wrote:
> >>
> >> On Thu, Nov 11, 2010 at 5:11 AM, Jeremy Orlow <jorlow@chromium.org>
> wrote:
> >> > On Mon, Nov 8, 2010 at 2:12 PM, <bugzilla@jessica.w3.org> wrote:
> >> >>
> >> >> http://www.w3.org/Bugs/Public/show_bug.cgi?id=11257
> >> >>
> >> >>           Summary: Should IDBCursor.update be able to create a new
> >> >> entry?
> >> >>           Product: WebAppsWG
> >> >>           Version: unspecified
> >> >>          Platform: PC
> >> >>        OS/Version: All
> >> >>            Status: NEW
> >> >>          Severity: normal
> >> >>          Priority: P2
> >> >>         Component: Indexed Database API
> >> >>        AssignedTo: dave.null@w3.org
> >> >>        ReportedBy: jonas@sicking.cc
> >> >>         QAContact: member-webapi-cvs@w3.org
> >> >>                CC: mike@w3.org, public-webapps@w3.org
> >> >>
> >> >>
> >> >> What should happen in the following case:
> >> >>
> >> >> db.transaction(["foo"]).objectStore("foo").openCursor().onsuccess =
> >> >> function(e)
> >> >> {
> >> >>  var cursor = e.result;
> >> >>  if (!cursor)
> >> >>    return;
> >> >>
> >> >>  cursor.delete();
> >> >>  cursor.update({ id: 1234, value: "Benny" });
> >> >> }
> >> >>
> >> >>
> >> >> This situation can of course arrive in more subtle ways:
> >> >>
> >> >> os = db.transaction(["foo"]).objectStore("foo");
> >> >> os.openCursor().onsuccess = function(e) {
> >> >>  var cursor = e.result;
> >> >>  if (!cursor)
> >> >>    return;
> >> >>
> >> >>  cursor.update({ id: 1234, value: "Benny" });
> >> >> }
> >> >> os.delete(1234);
> >> >>
> >> >>
> >> >> As specified, IDBCursor.update behaves just like IDBObjectStore.put
> and
> >> >> just
> >> >> creates a new entry, but this might be somewhat unexpected behavior.
> >> >
> >> > Let's just remove update and delete from IDBCursor and be done with
> it.
> >>
> >> The problem is that you can't always get to the key of the objectStore
> >> entry to delete/update. Specifically if the objectStore uses
> >> out-of-line keys the cursor doesn't expose those.
> >
> > Why not fix this use case then?  I.e. change the cursor to return
> .indexKey,
> > .primaryKey, .value (or something like that).  If we did this, we could
> even
> > get rid of the different between object cursors and key cursors (which
> > overload the .value to mean the primary key, which is quite confusing).
>
> I would be ok with exposing some new property which exposes the objectstore
> key.
>

And thus get rid of the openKeyCursor and getKey?  This would make the spec
a bit more complicated (we'd need to have 2 IDBCursor objects, one
that inherits from the other), but seems much simpler to use.  Shall I file
a bug?


> But I still think that .update and .delete are useful and logical API
> which has very little implementation cost.
>

I still don't understand why you think low implementation is important at
all when talking about these APIs.  If something is so insanely complex that
implementors would likely not implement it, then I can understand bringing
it up, but otherwise I think most people on this list can agree that it
should cary _very_ little weight when deciding whether API surface area is
worth it.

J
Received on Friday, 12 November 2010 05:13:31 GMT

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