Hi Alexander, I don't believe what you are asking for is currently doable, even in the latest 4.0 milestone release.
An ObjectContext doesn't know anything about read-only. You can make a Cayenne object read-only in Cayenne Modeler, however this just omits setter-type methods. CayenneDataObject, which all Cayenne database objects inherit from, doesn't actually restrict setting values if you flag it as read-only in the modeler. You can directly call writeProperty(), writePropertyDirectly(), removeToManyTarget(), etc on the objects. I think this feature would be fairly easy to add (the information is already in the model's XML files [1]), so perhaps it could be added before 4.0 final. I'd suggest: 1. Add a read-only flag to DataContext and friends. If you call commitChanges() on a read-only context, throw an exception. 2. Alter each CayenneDataObject which modifies data (writeProperty(), etc) to check the entity's read-only status AND the context's read-only status. If either is read-only and you are trying to sneak a change in, throw an exception. Does this sound like the right approach (to you and other Cayenne users)? As to your localObject() question, I think it should adhere to the 1/2 semantics I just mentioned. Thanks, mrg [1] <obj-entity name="..." className="..." readOnly="true" dbEntityName="..." superClassName="..."> On Fri, May 5, 2017 at 6:29 AM, Alexander <lex.f...@gmail.com> wrote: > Hi, > > I searched for a while, but wasn’t able to find a solution to make an > ObjectContext “read-only”. > Maybe I'm missing something. > > The point is: > As suggested many times, there are situations where it makes sense to have > a shared read-only ObjectContext and other ObjectContexts to commit changes. > I can certainly handle two and more ObjectContexts, but I need to lock out > other users / applications which can somehow gain access to persistent > objects instantiated through the assumed read-only shared context, since > any application that has access to such objects (maybe obtained from a > service class that is expected to return read-only objects) could simply > call object.getObjectContext().commitChanges(). By the way, this would > also commit unwanted temporary changes that happen elsewhere in the main > application or in the service class. > > Is there a method like CONTEXT.makeReadOnly() to make sure that any > objects that resides in this specific ObjectContext cannot be changed? > Even better, is there a way to let persistent objects, that are bound to a > read-only context, throw an exception? > > Should this be possible, there is only one question left: would it still > be possible to transfer objects retrieved through a read-only > ObjectContext to a read-write ObjectContext, by calling > localObject(readWriteContext)? > > Any help would be greatly appreciated. > Alexander > >
