Re: [aerogear-dev] Mutable vs Immutable for AGMemoryStore and AGPropertyStore

Hello all, Time to bring back the topic, on the immutability vs mutable issue for memory (an especially plist) storage. read method should return an immutable object. Make it all immutable will help consistency. thoughts? ++ Corinne On 25 Nov 2013, at 23:41, Corinne Krych <corinnekrych(a)gmail.com&gt; wrote: I see actually 2 correlated problems in the described use case: 1. Immutability. [store readAll] return a mutable object I can then modify without using 'save' method. In Objective-C, mutability is a strong concept [1]. But then immutability is not well supported in all languages... unmodifedCollection in Java not quite the same than immutable. I see 2 options: a) make slight API changes to cater both way like: void save(T item) could be replaced by T save(T item) b) change only iOS implementation and accept slight differences as each language idiomatic 2. PList Storage dump the whole content of memory storage in one file whether you go for save one element or save all element. But if we have immutability then it wouldn't be such a problem. ++ Corinne [1] https://developer.apple.com/library/mac/documentation/general/conceptual/... On 25 November 2013 22:17, Christos Vasilakis <cvasilak(a)gmail.com&gt; wrote: This effect is most visible in the Memory storage implementations, since the mutable objects returned can be modified without the user asks for an explicitly 'save' operation. In the scenario described, regardless if you did save or not, a later 'read' operation on the store, would have returned a possible modified object (done outside the store periphery). Other store types (aka SQL) don't suffer from this, since all read operations request the last state from permanent store. It all comes to this: a 'read' operation on a store _must_ guarantee to return the state of an object previously 'saved'. If the memory storage implementation fails on it, then 'read' should be fixed using each platform mutability semantics. If not mistaken, I believe this effect of mem storage is exhibited on our other platforms too. - Christos issue: copy of the NSArray and I save encrypted data in it be saved decrypted into permanent storage. this dato to my AGProperListStorage. Just this one. encrypted but the other data I ecrypted in memory were saved decrypted saving one data to permanent storage the all memory is dumped into plist resulting in decrypted value to be stored. NSMutableDictionary because you can save item (represented as Key/Value with NSMutableDictionary) without id, the store will take care of generating this id and assign it back into the item. is misleading because you can actually do mutable object save method return an immutable NSDictinary containing the item https://github.com/corinnekrych/aerogear-ios-cookbook/blob/master/Xmas/Xm... https://github.com/corinnekrych/aerogear-ios-cookbook/blob/master/Xmas/Xm... _______________________________________________ aerogear-dev mailing list aerogear-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/aerogear-dev