Re: Dates (1-day resolution) redux
On 12/08/2010, at 10:44 AM, Ramsey Lee Gurley wrote: > I believe the difference is that yes, GregorianCalendar _is_ timezone aware. > NSTimestamp is not. NSTimestamp's getTime() value is fixed when the > timestamp is created. If you then adjust your timezone frame of reference, > the time does not adjust with you. GregorianCalendar is the opposite. It > has fixed gregorian values (calendar day, month, year, etc) and the getTime() > value fluctuates based on the timezone you set on it. Maybe it would work then. I'll add it to my list of things to try. :-) -- Paul. http://logicsquad.net/ ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() /editingContext().revert()
You may already know this...If your thread belongs to the session, another option I think is MultiECLockManager. Cheers Cheong Hee - Original Message - From: "Farrukh Ijaz" To: "Chuck Hill" Cc: "WebObjects-Dev List" Sent: Thursday, August 12, 2010 5:47 AM Subject: Re: postNotification and editingContext().saveChanges() /editingContext().revert() Guessing, concurrent threads, and locking. Never a good combination. Thanks Chuck! Is there any choice then? Or every Workflow may have it's own editingContext() considering the ec would be lightweight and won't do anything else except modifying a single row? On Aug 11, 2010, at 2:35 PM, Farrukh Ijaz wrote: I am using ERXEC with default settings. I guess it takes care of the locking automatically. Sent from my iPad On 11-Aug-2010, at 11:58 PM, Chuck Hill wrote: On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: Sent from my iPad On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: Hi All, Is it safe to invoke editingContext().saveChange() or editingContext().revert() in a method that is used through NSSelector and invoked by the NSNotificationCenter on postNotification()? That likely depends on which notification. Okay, here is the real scenario. I have developed a Workflow Engine which is capable to run multiple workflows in parallel in their individual threads. Each workflow has methods as start(), stop(), suspend(), and resume(). The behavior of these methods is understood. Everything remains in memory. Now in order to persist their state I have created a corresponding entity. There are two columns of the entity, status and serializedInstance which change at any stage and that is depending upon user actions and workflow code. I have a workflow management dashboard which provides ability to view all the workflows defined in the system and to start, stop, resume and suspend. When I start the workflow, I call the method start() of the workflow entity, which internally triggers the associated workflow's start() method and also registers the entity to receive notifications from the workflow thread. The workflow thread post notifications such as when it completes the job or explicitly stopped, resumed, suspended etc. So upon these notifications, the workflow entity's onNotify() method is invoked which in turn based on the message, modifies the status column and serializedInstance column value and invokes, editingContext().saveChanges() inside the onNotify() method. You will have to make sure that the EC is locked before touching any of the entity's persistent values or calling saveChanges() I guess the story is too long but it is working fine so far. I just want to confirm that if this does not break anything at any stage or cause a deadlock situation? Chuck -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/chng34%40gmail.com This email sent to chn...@gmail.com ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
On Aug 11, 2010, at 2:47 PM, Farrukh Ijaz wrote: > > >> Guessing, concurrent threads, and locking. Never a good combination. > > Thanks Chuck! Is there any choice then? Or every Workflow may have it's own > editingContext() considering the ec would be lightweight and won't do > anything else except modifying a single row? I think the thread should own the EC. It is still responsible to lock and unlock it. And you probably don't need the notifications in this case. Chuck >> On Aug 11, 2010, at 2:35 PM, Farrukh Ijaz wrote: >> >>> I am using ERXEC with default settings. I guess it takes care of the >>> locking automatically. >>> >>> Sent from my iPad >>> >>> On 11-Aug-2010, at 11:58 PM, Chuck Hill wrote: >>> On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: > > > Sent from my iPad > > On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: > >> >> On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: >> >>> Hi All, >>> >>> Is it safe to invoke editingContext().saveChange() or >>> editingContext().revert() in a method that is used through NSSelector >>> and invoked by the NSNotificationCenter on postNotification()? >> >> >> That likely depends on which notification. > > Okay, here is the real scenario. I have developed a Workflow Engine which > is capable to run multiple workflows in parallel in their individual > threads. Each workflow has methods as start(), stop(), suspend(), and > resume(). The behavior of these methods is understood. Everything remains > in memory. Now in order to persist their state I have created a > corresponding entity. There are two columns of the entity, status and > serializedInstance which change at any stage and that is depending upon > user actions and workflow code. > > I have a workflow management dashboard which provides ability to view all > the workflows defined in the system and to start, stop, resume and > suspend. When I start the workflow, I call the method start() of the > workflow entity, which internally triggers the associated workflow's > start() method and also registers the entity to receive notifications > from the workflow thread. The workflow thread post notifications such as > when it completes the job or explicitly stopped, resumed, suspended etc. > So upon these notifications, the workflow entity's onNotify() method is > invoked which in turn based on the message, modifies the status column > and serializedInstance column value and invokes, > editingContext().saveChanges() inside the onNotify() method. You will have to make sure that the EC is locked before touching any of the entity's persistent values or calling saveChanges() > > I guess the story is too long but it is working fine so far. I just want > to confirm that if this does not break anything at any stage or cause a > deadlock situation? > >> >> Chuck >> >> -- >> Chuck Hill Senior Consultant / VP Development >> >> Practical WebObjects - for developers who want to increase their overall >> knowledge of WebObjects or who are trying to solve specific problems. >> http://www.global-village.net/products/practical_webobjects >> >> >> >> >> >> >> -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects >> >> -- >> Chuck Hill Senior Consultant / VP Development >> >> Practical WebObjects - for developers who want to increase their overall >> knowledge of WebObjects or who are trying to solve specific problems. >> http://www.global-village.net/products/practical_webobjects >> >> >> >> >> >> >> -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects smime.p7s Description: S/MIME cryptographic signature ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
On Aug 11, 2010, at 8:20 PM, Paul Hoadley wrote: > Hi Ramsey, > > On 12/08/2010, at 9:19 AM, Ramsey Lee Gurley wrote: > >> Perhaps this is a stupid question, but is there any reason a >> GregorianCalendar wouldn't work? It seems it only needs a simple subclass >> providing factory methods for an EOAttribute prototype. > > GregorianCalendar has millisecond resolution and is timezone-aware, so I > don't know that it's going to be an improvement on NSTimestamp. Is it? > > > -- > Paul. http://developer.apple.com/legacy/mac/library/documentation/InternetWeb/Reference/WO542Reference/com/webobjects/foundation/NSTimestamp.html If I'm wrong, I blame the Apple docs for misleading me (^_^) I believe the difference is that yes, GregorianCalendar _is_ timezone aware. NSTimestamp is not. NSTimestamp's getTime() value is fixed when the timestamp is created. If you then adjust your timezone frame of reference, the time does not adjust with you. GregorianCalendar is the opposite. It has fixed gregorian values (calendar day, month, year, etc) and the getTime() value fluctuates based on the timezone you set on it. Ramsey ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Hi Ramsey, On 12/08/2010, at 9:19 AM, Ramsey Lee Gurley wrote: > Perhaps this is a stupid question, but is there any reason a > GregorianCalendar wouldn't work? It seems it only needs a simple subclass > providing factory methods for an EOAttribute prototype. GregorianCalendar has millisecond resolution and is timezone-aware, so I don't know that it's going to be an improvement on NSTimestamp. Is it? -- Paul. http://logicsquad.net/ ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Hi Henrique, On 12/08/2010, at 3:31 AM, Henrique Prange wrote: > Have you tried Joda Time LocalDate [1]? > > "LocalDate is an immutable datetime class representing a date without a time > zone." > > You could create a custom type to map the DATE external type to the LocalDate > class, instead of using NSTimestamp or java.util.Date. It is similar to the > Boolean solution. Thanks, I will look at that. How much work is involved in using custom types like this? (I've never done it before.) For example, do I need to provide a corresponding custom comparator somewhere so that EOF can sort on this attribute? -- Paul. http://logicsquad.net/ ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Perhaps this is a stupid question, but is there any reason a GregorianCalendar wouldn't work? It seems it only needs a simple subclass providing factory methods for an EOAttribute prototype. Ramsey On Aug 11, 2010, at 11:10 AM, Mike Schrag wrote: > Julian Day is a really handy way to store days, too ... You get easy relative > comparison, and there are plenty of impls in java for making covers on your > EOs. > > On Aug 11, 2010, at 10:27 AM, David Avendasora wrote: > >> On Aug 10, 2010, at 10:04 AM, Jon Nolan wrote: >> >>> IMO, this fight is absolutely not worth the effort. Store your "birthday" >>> attributes as integers (19700302) or strings and create cover methods on >>> your EOs to convert to date and back. >> >> This seems the most accurate way to handle it. Noon GMT just displaces the >> problem to the opposite side of the planet, no? It would have to be noon in >> the timezone in which the event is recorded, but then, what if the user >> moves? A mess. >> >> This is something that we are going to be dealing with as our markets >> expands globally. Some dates are locale-specific, some aren't, and some can >> even be locale-specific but only when compared to other local-specific dates >> (it would be helpful to know that you're wishing someone a happy birthday on >> the day they recognize as their birthday and not a day late). >> >> Dave >> >> >> ___ >> Do not post admin requests to the list. They will be ignored. >> Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) >> Help/Unsubscribe/Update your Subscription: >> http://lists.apple.com/mailman/options/webobjects-dev/mschrag%40pobox.com >> >> This email sent to msch...@pobox.com > > ___ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/webobjects-dev/rgurley%40mac.com > > This email sent to rgur...@mac.com ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
On 11/08/2010, at 11:57 PM, David Avendasora wrote: > On Aug 10, 2010, at 10:04 AM, Jon Nolan wrote: > >> IMO, this fight is absolutely not worth the effort. Store your "birthday" >> attributes as integers (19700302) or strings and create cover methods on >> your EOs to convert to date and back. > > This seems the most accurate way to handle it. Noon GMT just displaces the > problem to the opposite side of the planet, no? It would have to be noon in > the timezone in which the event is recorded, but then, what if the user > moves? A mess. I agree that it's a mess. The normalise-to-noon idea seemed attractive to me, though, because it would require almost no intervention (just a single extra method call) in an app that's already in production. Maybe that's a false economy. -- Paul. http://logicsquad.net/ ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
> Guessing, concurrent threads, and locking. Never a good combination. Thanks Chuck! Is there any choice then? Or every Workflow may have it's own editingContext() considering the ec would be lightweight and won't do anything else except modifying a single row? > > > On Aug 11, 2010, at 2:35 PM, Farrukh Ijaz wrote: > >> I am using ERXEC with default settings. I guess it takes care of the locking >> automatically. >> >> Sent from my iPad >> >> On 11-Aug-2010, at 11:58 PM, Chuck Hill wrote: >> >>> >>> On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: >>> Sent from my iPad On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: > > On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: > >> Hi All, >> >> Is it safe to invoke editingContext().saveChange() or >> editingContext().revert() in a method that is used through NSSelector >> and invoked by the NSNotificationCenter on postNotification()? > > > That likely depends on which notification. Okay, here is the real scenario. I have developed a Workflow Engine which is capable to run multiple workflows in parallel in their individual threads. Each workflow has methods as start(), stop(), suspend(), and resume(). The behavior of these methods is understood. Everything remains in memory. Now in order to persist their state I have created a corresponding entity. There are two columns of the entity, status and serializedInstance which change at any stage and that is depending upon user actions and workflow code. I have a workflow management dashboard which provides ability to view all the workflows defined in the system and to start, stop, resume and suspend. When I start the workflow, I call the method start() of the workflow entity, which internally triggers the associated workflow's start() method and also registers the entity to receive notifications from the workflow thread. The workflow thread post notifications such as when it completes the job or explicitly stopped, resumed, suspended etc. So upon these notifications, the workflow entity's onNotify() method is invoked which in turn based on the message, modifies the status column and serializedInstance column value and invokes, editingContext().saveChanges() inside the onNotify() method. >>> >>> You will have to make sure that the EC is locked before touching any of the >>> entity's persistent values or calling saveChanges() >>> I guess the story is too long but it is working fine so far. I just want to confirm that if this does not break anything at any stage or cause a deadlock situation? > > Chuck > > -- > Chuck Hill Senior Consultant / VP Development > > Practical WebObjects - for developers who want to increase their overall > knowledge of WebObjects or who are trying to solve specific problems. > http://www.global-village.net/products/practical_webobjects > > > > > > > >>> >>> -- >>> Chuck Hill Senior Consultant / VP Development >>> >>> Practical WebObjects - for developers who want to increase their overall >>> knowledge of WebObjects or who are trying to solve specific problems. >>> http://www.global-village.net/products/practical_webobjects >>> >>> >>> >>> >>> >>> >>> > > -- > Chuck Hill Senior Consultant / VP Development > > Practical WebObjects - for developers who want to increase their overall > knowledge of WebObjects or who are trying to solve specific problems. > http://www.global-village.net/products/practical_webobjects > > > > > > > ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
Guessing, concurrent threads, and locking. Never a good combination. On Aug 11, 2010, at 2:35 PM, Farrukh Ijaz wrote: > I am using ERXEC with default settings. I guess it takes care of the locking > automatically. > > Sent from my iPad > > On 11-Aug-2010, at 11:58 PM, Chuck Hill wrote: > >> >> On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: >> >>> >>> >>> Sent from my iPad >>> >>> On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: >>> On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: > Hi All, > > Is it safe to invoke editingContext().saveChange() or > editingContext().revert() in a method that is used through NSSelector and > invoked by the NSNotificationCenter on postNotification()? That likely depends on which notification. >>> >>> Okay, here is the real scenario. I have developed a Workflow Engine which >>> is capable to run multiple workflows in parallel in their individual >>> threads. Each workflow has methods as start(), stop(), suspend(), and >>> resume(). The behavior of these methods is understood. Everything remains >>> in memory. Now in order to persist their state I have created a >>> corresponding entity. There are two columns of the entity, status and >>> serializedInstance which change at any stage and that is depending upon >>> user actions and workflow code. >>> >>> I have a workflow management dashboard which provides ability to view all >>> the workflows defined in the system and to start, stop, resume and suspend. >>> When I start the workflow, I call the method start() of the workflow >>> entity, which internally triggers the associated workflow's start() method >>> and also registers the entity to receive notifications from the workflow >>> thread. The workflow thread post notifications such as when it completes >>> the job or explicitly stopped, resumed, suspended etc. So upon these >>> notifications, the workflow entity's onNotify() method is invoked which in >>> turn based on the message, modifies the status column and >>> serializedInstance column value and invokes, editingContext().saveChanges() >>> inside the onNotify() method. >> >> You will have to make sure that the EC is locked before touching any of the >> entity's persistent values or calling saveChanges() >> >>> >>> I guess the story is too long but it is working fine so far. I just want to >>> confirm that if this does not break anything at any stage or cause a >>> deadlock situation? >>> Chuck -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects >> >> -- >> Chuck Hill Senior Consultant / VP Development >> >> Practical WebObjects - for developers who want to increase their overall >> knowledge of WebObjects or who are trying to solve specific problems. >> http://www.global-village.net/products/practical_webobjects >> >> >> >> >> >> >> -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects smime.p7s Description: S/MIME cryptographic signature ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
I am using ERXEC with default settings. I guess it takes care of the locking automatically. Sent from my iPad On 11-Aug-2010, at 11:58 PM, Chuck Hill wrote: > > On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: > >> >> >> Sent from my iPad >> >> On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: >> >>> >>> On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: >>> Hi All, Is it safe to invoke editingContext().saveChange() or editingContext().revert() in a method that is used through NSSelector and invoked by the NSNotificationCenter on postNotification()? >>> >>> >>> That likely depends on which notification. >> >> Okay, here is the real scenario. I have developed a Workflow Engine which is >> capable to run multiple workflows in parallel in their individual threads. >> Each workflow has methods as start(), stop(), suspend(), and resume(). The >> behavior of these methods is understood. Everything remains in memory. Now >> in order to persist their state I have created a corresponding entity. There >> are two columns of the entity, status and serializedInstance which change at >> any stage and that is depending upon user actions and workflow code. >> >> I have a workflow management dashboard which provides ability to view all >> the workflows defined in the system and to start, stop, resume and suspend. >> When I start the workflow, I call the method start() of the workflow entity, >> which internally triggers the associated workflow's start() method and also >> registers the entity to receive notifications from the workflow thread. The >> workflow thread post notifications such as when it completes the job or >> explicitly stopped, resumed, suspended etc. So upon these notifications, the >> workflow entity's onNotify() method is invoked which in turn based on the >> message, modifies the status column and serializedInstance column value and >> invokes, editingContext().saveChanges() inside the onNotify() method. > > You will have to make sure that the EC is locked before touching any of the > entity's persistent values or calling saveChanges() > >> >> I guess the story is too long but it is working fine so far. I just want to >> confirm that if this does not break anything at any stage or cause a >> deadlock situation? >> >>> >>> Chuck >>> >>> -- >>> Chuck Hill Senior Consultant / VP Development >>> >>> Practical WebObjects - for developers who want to increase their overall >>> knowledge of WebObjects or who are trying to solve specific problems. >>> http://www.global-village.net/products/practical_webobjects >>> >>> >>> >>> >>> >>> >>> > > -- > Chuck Hill Senior Consultant / VP Development > > Practical WebObjects - for developers who want to increase their overall > knowledge of WebObjects or who are trying to solve specific problems. > http://www.global-village.net/products/practical_webobjects > > > > > > > ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
On Aug 11, 2010, at 1:41 PM, Farrukh Ijaz wrote: > > > Sent from my iPad > > On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: > >> >> On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: >> >>> Hi All, >>> >>> Is it safe to invoke editingContext().saveChange() or >>> editingContext().revert() in a method that is used through NSSelector and >>> invoked by the NSNotificationCenter on postNotification()? >> >> >> That likely depends on which notification. > > Okay, here is the real scenario. I have developed a Workflow Engine which is > capable to run multiple workflows in parallel in their individual threads. > Each workflow has methods as start(), stop(), suspend(), and resume(). The > behavior of these methods is understood. Everything remains in memory. Now in > order to persist their state I have created a corresponding entity. There are > two columns of the entity, status and serializedInstance which change at any > stage and that is depending upon user actions and workflow code. > > I have a workflow management dashboard which provides ability to view all the > workflows defined in the system and to start, stop, resume and suspend. When > I start the workflow, I call the method start() of the workflow entity, which > internally triggers the associated workflow's start() method and also > registers the entity to receive notifications from the workflow thread. The > workflow thread post notifications such as when it completes the job or > explicitly stopped, resumed, suspended etc. So upon these notifications, the > workflow entity's onNotify() method is invoked which in turn based on the > message, modifies the status column and serializedInstance column value and > invokes, editingContext().saveChanges() inside the onNotify() method. You will have to make sure that the EC is locked before touching any of the entity's persistent values or calling saveChanges() > > I guess the story is too long but it is working fine so far. I just want to > confirm that if this does not break anything at any stage or cause a deadlock > situation? > >> >> Chuck >> >> -- >> Chuck Hill Senior Consultant / VP Development >> >> Practical WebObjects - for developers who want to increase their overall >> knowledge of WebObjects or who are trying to solve specific problems. >> http://www.global-village.net/products/practical_webobjects >> >> >> >> >> >> >> -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects smime.p7s Description: S/MIME cryptographic signature ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
Sent from my iPad On 11-Aug-2010, at 7:35 PM, Chuck Hill wrote: > > On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: > >> Hi All, >> >> Is it safe to invoke editingContext().saveChange() or >> editingContext().revert() in a method that is used through NSSelector and >> invoked by the NSNotificationCenter on postNotification()? > > > That likely depends on which notification. Okay, here is the real scenario. I have developed a Workflow Engine which is capable to run multiple workflows in parallel in their individual threads. Each workflow has methods as start(), stop(), suspend(), and resume(). The behavior of these methods is understood. Everything remains in memory. Now in order to persist their state I have created a corresponding entity. There are two columns of the entity, status and serializedInstance which change at any stage and that is depending upon user actions and workflow code. I have a workflow management dashboard which provides ability to view all the workflows defined in the system and to start, stop, resume and suspend. When I start the workflow, I call the method start() of the workflow entity, which internally triggers the associated workflow's start() method and also registers the entity to receive notifications from the workflow thread. The workflow thread post notifications such as when it completes the job or explicitly stopped, resumed, suspended etc. So upon these notifications, the workflow entity's onNotify() method is invoked which in turn based on the message, modifies the status column and serializedInstance column value and invokes, editingContext().saveChanges() inside the onNotify() method. I guess the story is too long but it is working fine so far. I just want to confirm that if this does not break anything at any stage or cause a deadlock situation? > > Chuck > > -- > Chuck Hill Senior Consultant / VP Development > > Practical WebObjects - for developers who want to increase their overall > knowledge of WebObjects or who are trying to solve specific problems. > http://www.global-village.net/products/practical_webobjects > > > > > > > ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
[WOWODC 2010] 3 days left for registration!
Hello everyone, This is the last message about WOWODC 2010, I promise! Registration close in 3 days, so hurry up if you want to join us for 3 days of learning and fun! About the hotel, we ran out of rooms in our room block, and the hotel is almost full, the only rooms available are the superior ($169+) and business class ($199+). Since the room block is full, you can't apply for the "Stay at the hotel" rebate. If you want a cheaper alternative for your room, check the Grand Plaza : http://www.grandplazamontreal.com/ See you in two weeks! Can't wait to drink some beers with other WO devs :-) Pascal Robert prob...@macti.ca AIM: MacTICanada Twitter : pascal_robert LinkedIn : http://www.linkedin.com/in/macti WO Community profile : http://wocommunity.org/page/member?name=probert ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Hi Paul, Have you tried Joda Time LocalDate [1]? "LocalDate is an immutable datetime class representing a date without a time zone." You could create a custom type to map the DATE external type to the LocalDate class, instead of using NSTimestamp or java.util.Date. It is similar to the Boolean solution. [1]http://joda-time.sourceforge.net/apidocs/org/joda/time/LocalDate.html Cheers, Henrique On 11/08/2010, at 03:56, Paul Hoadley wrote: > On 10/08/2010, at 11:33 PM, John Huss wrote: > >> On Tue, Aug 10, 2010 at 6:12 AM, Paul Hoadley wrote: >> For the attribute that we may as well call the "birthday" attribute, I'm >> using the "date" prototype from ERPrototypes. Curiously (IMHO), this >> prototype has an external type of "TIMESTAMP", even though Postgres offers >> the 1-day-resolution "DATE" type. In any case, I stuck with the prototype >> as shipped. >> >> I would consider that a bug in ERPrototypes, since there is a dateTime >> prototype, the date prototype only makes sense if it is different. But >> fixing it is difficult since it could break everyone using it. Even so, it >> wouldn't be the first time such a thing was done, and I am a proponent of >> getting things right, as long as the community is sufficiently notified. > > I wonder if it's incidental to the real problem, though, which is that EOF > and Java have no 1-day-resolution date type. That is, and I haven't tested > it (though it's on my list), I'm not sure that using PostgreSQL's DATE type > would actually solve the problem. > > > -- > Paul. > > http://logicsquad.net/ > > > ___ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/webobjects-dev/hprange%40gmail.com > > This email sent to hpra...@gmail.com ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: postNotification and editingContext().saveChanges() / editingContext().revert()
On Aug 11, 2010, at 2:11 AM, Farrukh Ijaz wrote: > Hi All, > > Is it safe to invoke editingContext().saveChange() or > editingContext().revert() in a method that is used through NSSelector and > invoked by the NSNotificationCenter on postNotification()? That likely depends on which notification. Chuck -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects smime.p7s Description: S/MIME cryptographic signature ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Julian Day is a really handy way to store days, too ... You get easy relative comparison, and there are plenty of impls in java for making covers on your EOs. On Aug 11, 2010, at 10:27 AM, David Avendasora wrote: > On Aug 10, 2010, at 10:04 AM, Jon Nolan wrote: > >> IMO, this fight is absolutely not worth the effort. Store your "birthday" >> attributes as integers (19700302) or strings and create cover methods on >> your EOs to convert to date and back. > > This seems the most accurate way to handle it. Noon GMT just displaces the > problem to the opposite side of the planet, no? It would have to be noon in > the timezone in which the event is recorded, but then, what if the user > moves? A mess. > > This is something that we are going to be dealing with as our markets expands > globally. Some dates are locale-specific, some aren't, and some can even be > locale-specific but only when compared to other local-specific dates (it > would be helpful to know that you're wishing someone a happy birthday on the > day they recognize as their birthday and not a day late). > > Dave > > > ___ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/webobjects-dev/mschrag%40pobox.com > > This email sent to msch...@pobox.com ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
On Aug 10, 2010, at 10:04 AM, Jon Nolan wrote: > IMO, this fight is absolutely not worth the effort. Store your "birthday" > attributes as integers (19700302) or strings and create cover methods on your > EOs to convert to date and back. This seems the most accurate way to handle it. Noon GMT just displaces the problem to the opposite side of the planet, no? It would have to be noon in the timezone in which the event is recorded, but then, what if the user moves? A mess. This is something that we are going to be dealing with as our markets expands globally. Some dates are locale-specific, some aren't, and some can even be locale-specific but only when compared to other local-specific dates (it would be helpful to know that you're wishing someone a happy birthday on the day they recognize as their birthday and not a day late). Dave ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Hi Andrew, On 11/08/2010, at 6:11 PM, Andrew Lindesay wrote: > I'm not sure if that would work if you had people viewing and entering data > from the perspective of different time-zones? Maybe it would be better to > normalise to midday for the user's timezone as opposed to the application > server's timezone -- assuming your application server operates in GMT+0. Thanks Andrew. I think you're right. -- Paul. http://logicsquad.net/ ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
postNotification and editingContext().saveChanges() / editingContext().revert()
Hi All, Is it safe to invoke editingContext().saveChange() or editingContext().revert() in a method that is used through NSSelector and invoked by the NSNotificationCenter on postNotification()? Thanks, Farrukh ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
Hello Paul;
I'm not sure if that would work if you had people viewing and entering data
from the perspective of different time-zones? Maybe it would be better to
normalise to midday for the user's timezone as opposed to the application
server's timezone -- assuming your application server operates in GMT+0.
cheers.
>> public static NSTimestamp normalisedDate(NSTimestamp date) {
...
> Thanks for all the input on this. I think I'll try the approach above in the
> first instance.
___
Andrew Lindesay
www.silvereye.co.nz
___
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (Webobjects-dev@lists.apple.com)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
Re: Dates (1-day resolution) redux
On 10/08/2010, at 11:44 PM, Simon wrote:
> For dates like this, I force the time component to 12:00 noon. That at least
> reduces the chance of timezone shifts of the day portion.
>
> Chuck
>
> same here:
>
> public static NSTimestamp normalisedDate(NSTimestamp date) {
> GregorianCalendar gc = new GregorianCalendar();
> gc.setTime(date);
> int d = gc.get(GregorianCalendar.DAY_OF_MONTH);
> int m = gc.get(GregorianCalendar.MONTH) + 1;
> int y = gc.get(GregorianCalendar.YEAR);
> NSTimeZone tz = NSTimeZone.systemTimeZone();
> return new NSTimestamp(y, m, d, 12, 0, 0, tz);
> }
>
> over 250 references to that method in our code base!
Thanks for all the input on this. I think I'll try the approach above in the
first instance.
--
Paul.
http://logicsquad.net/
___
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (Webobjects-dev@lists.apple.com)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
