Re: Unexpected awakeFromInsertion() behaviour
Re: Unexpected awakeFromInsertion() behaviour
- Subject: Re: Unexpected awakeFromInsertion() behaviour
- From: "Mr. Pierre Frisch" <email@hidden>
- Date: Thu, 10 Jan 2008 12:31:29 -0800
I am not entirely sure of what the behavior should be but after the
save the object is in the DB so this not a newly inserted object
anymore. We do a deleteObject() and a revert() logically we should
call awakeFromFetch() as this would have reverted the object to its
fetched state (last snapshot), awakeFromInsertion() just does not
appears to make sense.
Pierre
--
Pierre Frisch
email@hidden
On Jan 10, 2008, at 11:35, Chuck Hill wrote:
I will let Peter file the report. But while you are waiting...
What do you think is the correct behavior here? Should it not call
awakeFromInsertion again? Should it call it and undo any changes?
Should it call it and detect that the object has been updated?
Calling revert() should, I think, return the contents of the EC to
the last state where there were no changes (after the previous save
if it has been saved, or will all local changes undone). Calling
awakeFromInsertion() does not seem compatible with that.
Chuck
On Jan 10, 2008, at 11:30 AM, Mr. Pierre Frisch wrote:
Bug report please this needs to be fixed.
Pierre
--
Pierre Frisch
email@hidden
On Jan 10, 2008, at 11:04, Chuck Hill wrote:
That looks like a bug, the EC should either not be calling
awakeFromInsertion() or should be seeing the notifications from
the change in value. It makes sense to me for it to call
awakeFromInsertion() *BUT* this results in an object state
different from what was there before the changes being reverted.
That seems to be a very wrong result.
You will often see the method written as:
// in Order.java
public void awakeFromInsertion(EOEditingContext ec) {
super.awakeFromInsertion(ec);
if (statusMessage() == null) {
setStatusMessage("incomplete");
}
}
I don't do that myself (I probably should!), but I expect this is
done to handle the situation you are seeing.
Chuck
On Jan 9, 2008, at 3:37 PM, Peter Vandoros wrote:
Hi Chuck,
Chuck Hill wrote:
Hi Peter,
On Jan 9, 2008, at 2:49 PM, Peter Vandoros wrote:
Chuck Hill wrote:
On Jan 8, 2008, at 9:23 PM, Peter Vandoros wrote:
I came across an interesting behaviour today with
awakeFromInsertion() that i did not expect and I hope someone
could shed some light.
What happens is that awakeFromInsertion() is not only called
when the EO is "created" but also when reverting the editing
context after having deleted an EO (which hasn't yet been
saved). That is, if you delete an EO and revert() instead of
saveChanges(), that EO's awakeFromInsertion() method is
called again.
The documentation states:
"Overridden by subclasses to perform additional
initialization on the receiver upon its being inserted into
ec. This is commonly used to assign default values or record
the time of insertion. ...."
I originally took this to mean that it is only called when
the EO is _created_. Technically speaking, the documentation
states that it is called when the EO is _inserted_ into the
editing context which does not necessarily mean when the EO
is _created_.
Does this mean that I need to go through all my EO's that use
this method for some initialisation and take this scenario
into account or is this a bug with WO?
I am using WO 5.2.4.
Is this what you are talking about?
com.webobjects.eocontrol.EOEditingContext ec =
newEditingContext();
ec.lock();
Order o = new Order();
ec.insertObject(o);
ec.deleteObject(o);
ec.revert();
ec.unlock();
I log a stack trace from Order.awakeFromInsertion. I do not
get a call to awakeFromInsertion when the ec is reverted in WO
5.3.3.
Log out a stack trace from awakeFromInsertion and see what it
says for the second call:
public void awakeFromInsertion(EOEditingContext ec)
{
NSLog.out.appendln(new RuntimeException("backtrace"));
super.awakeFromInsertion(ec);
. . .
I'd be interested to see it.
That is not exactly what i am talking about.
The code below demonstrates what i am talking about.
EOEditingContext ec = new EOEditingContext();
ec.lock();
try {
Order order = (Order)
EOUtilities.createAndInsertInstance( ec, "Order" );
// set order properties so it can be saved successfully
ec.saveChanges();
ec.deleteObject( order);
NSLog.out.appendln("should see awakeFromInsertion call
now...");
ec.revert();
NSLog.out.appendln("did you see the awakeFromInsertion call?");
}
catch (Exception e) {
System.err.println("Error with test");
e.printStackTrace();
}
finally {
ec.unlock();
}
The stack trace (the interesting part) that i get when this
happens is:
java.lang.RuntimeException: backtrace
at com.etechgroup.test.eo.Order.awakeFromInsertion(Order.java:
44)
at
com
.webobjects
.eocontrol
.EOEditingContext
.insertObjectWithGlobalID(EOEditingContext.java:2851)
at
com
.webobjects
.eocontrol.EOEditingContext.insertObject(EOEditingContext.java:
2871)
at
com
.webobjects
.eocontrol.EOEditingContext.revert(EOEditingContext.java:4570)
It looks as though the editing context re-inserts a deleted EO
if that EO is not newly created and you revert.
Of course it does! deleteObject makes the object not exist.
Reverting that makes it exist again. So it is newly created and
get awoken again. Revert is more like undo than "forget what I
just changed".
ec.deleteObject(order);
ec.saveChanges();
ec.undo();
ec.saveChanges();
I am not sure of the exact calls, but it is possible to reverse
changes committed to the database. Or it was at one time, I
have seen this happen due to a bug processing delete rules.
Much fun debugging that one.
I can imagine :-)
I'm glad i cleared this up and gave other people on this list a
heads up about this behaviour. At least now I know about this and
have worked around it by creating a new method in my generic
record super class awakeFromCreate() which is called by
awakeFromInsertion() only if the EO is newly created. This way,
it does what i thought awakeFromInsertion() does and what i was
using it for.
On a side note, i also noticed that if the default values that
are set in awakeFromInsertion() differ from the committed value,
EOF does not pick up that change leaving that EO/EditingContext
in an invalid state. This is actually what bit me yesterday and
lead me to investigate this behaviour.
This one _may_ be a bug. I can report it if you think it is a bug.
For example:
// in Order.java
public void awakeFromInsertion(EOEditingContext ec) {
super.awakeFromInsertion(ec);
setStatusMessage("incomplete");
}
// in SomeTestFile.java
EOEditingContext ec = new EOEditingContext();
ec.lock();
try {
Order order = (Order) EOUtilities.createAndInsertInstance( ec,
"Order" );
order.setStatusMessage("complete");
ec.saveChanges();
ec.deleteObject( order );
System.out.println("should see awakeFromInsertion call now...");
ec.revert();
System.out.println("did you see the awakeFromInsertion call?");
// the stateMessage should be 'complete' but you will see that
it is 'incomplete'
NSLog.out.appendln("order.statusMessage should be 'complete',
but it is: " + order.statusMessage());
// the editing context also does not show any changes
NSLog.out.appendln("ec.hasChanges: " + ec.hasChanges());
NSLog.out.appendln("ec.insertedObjects: " +
ec.insertedObjects().count());
NSLog.out.appendln("ec.updatedObjects: " +
ec.updatedObjects().count());
NSLog.out.appendln("ec.deletedObjects: " +
ec.deletedObjects().count());
}
catch (Exception e) {
System.err.println("Error with test");
e.printStackTrace();
}
finally {
ec.unlock();
}
As always Chuck, your help is much appreciated.
Thanks
--
Peter Vandoros
Software Engineer
Etech Group Pty Ltd
Level 3/21 Victoria St
Melbourne VIC 3000
Australia
Ph: +61 3 9639 9677
Fax: +61 3 9639 9577
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