I am going to use my first app classes in my second app through wcf.
Now I want to know it is possible to call my classes from first app with all properties and methods related it?
Related
How should I pass several app delegate properties into a cocoa touch framework method?
I'm thinking of using a protocol with required properties and use the type of protocol as my method argument type.
Obviously the framework needs to know what properties exist.
However, it doesn't feel right to pass the app delegate into a method like this.
PS. I know a good question shouldn't include "should" but I think it's relevant in this case.
Yes, don't pass the AppDelegate into your own custom code. That creates a coupling that is far far too tight.
Much better to at the right point unpack the properties you need, pack those into a struct and pass that into your framework.
there is a conceptional question:
I want to have a wrapper class which forwarding all called selectors to a given object. How do I do this?
And here is why:
I have a library for synchronizing data with a service. And I use Core Data.
For the library I have to create classes of a specific protocol. But I can not use the same protocol for the Core Data subclasses.
My idea is to create a subclass of the specific protocol and forwarding the protocol calls to the Core Data Object.
But there are many subclasses and many properties per subclass and without changing the Core Data subclasses (project specific requirement!)
Is there a way to do this without overwriting every method?
Thanks for your time =)
Implement -forwardingTargetForSelector:. You can return another object to forward unknown messages to. If that is most of what your class will do, you may want to just subclass from NSProxy rather than NSObject. (NSProxy has the advantage that it doesn't implement all of the standard NSObject methods, so you can forward those as well.)
One common problem with this approach is that the compiler will complain that your class does not respond to the selectors you're sending it. The usual way to address this is by requiring that users of your object declare it as id. This can often be inconvenient as well, so this is a bit of a last resort if other approaches are not possible.
But usually the better approach is to make your class a subclass of the target and add the additional methods required for your protocol. Or you can add the additional methods to the Core Data class via a category.
The answer to your specific question is yes. Message Forwarding contains everything you need.
I think you might want to step back and evaluate other options. For example, can you add this functionality to a base class instead of a proxy class.
I have a new project, kind of a board game, and I'm using a storyboard which has multiple view controllers in it - the game simply moves from one view to the next with the player making various decisions and then loops back.
I have an object which holds information about the player (along with a couple of methods) - the score etc. I obviously only need one instance of this object and as I want each View Controller to access the same instance, should it be a singleton? I've never used them before and I've read they're often over-used, so I just want to check if this is the correct way to do this from the start. Many thanks.
What you have described is the Model for your application, holding the game data and core logic. Is there any reason to make this a singleton rather than passing it between your controllers?!
I would assume one controller calls the next and so can pass this information across?! We use singletons for services and the like but not for model data, it's not really the point of them in our experience.
I personally have nothing against singletons, as long as you don't use too many of them in one project. While other people might recommend you use some other mediation for this project, I say go for it—this is exactly what you'd use a singleton for.
Singleton's can be be bad if you are developing a library component, a large server project, or for unit testing. But since you are doing an iphone game don't fret about it, it'll will be easier and faster just to use a singleton.
If you are worried about unit testing, since objetive-c is latebound and singletons are made with factory methods instead of constructors it's not hard to changeout the singleton for your unit test anyway.
What I have so far is a JSON file that I read inside the singleton. I use the singleton to be able to share data between different controllers.
Now I have to implement Core Data; I was wondering if I'm supposed to delete the singleton and just use the core data, or if I can implement it within the singleton?
Singleton works very well for Core Data.
Simply move all the methods from App Delegate to your singleton class and call them from there.
I've got a question about a Silverlight WCF Databinding pattern:
There are many examples about how to bind data using {Binding} expressions in XAML, how to make async calls to a WCF service, set the DataContext property of a element in the UI, how to use ObservableCollections and INotifyPropertyChanged, INotifyCollectionChanged and so on.
Background:
I'm using the MVVM pattern, and have a Silverlight ItemsControl, whose ItemsSource is set to an ObservableCollection property on my ViewModel object. My view is of course the XAML which has the {Binding}. Say the model object is called 'Metric'. My ViewModel periodically makes calls to a WCF service that returns ObservableCollection. MetricInfo is the data transfer object (DTO).
My question is two-fold:
Is there any way to avoid copying each property of MetricInfo to the model class - Metric?
When the WCF calls completes, is there any way to make sure I sync the items which are in both my local ObservableCollection and the result of the WCF call - without having to first clear out all the items in the local collection and then add all the ones from the WCF call result?
thanks,
Krishna
1) I have done the mapping through a constructor like this:
public Metric(MetricInfo metricInfoDTO)
then map the properties from the DTO to the entity which of course is what you are trying to avoid. Yes, this is a bit of work but for me it has worked out very well. The alternative could be to use a object mapper like AutoMapper
2) I suppose you could have some kind of comparison logic to do updates and inserts into the collection. For me, I have done the clear and add which you describe in you question. It's simple, short and I haven't had any issues with it.