Hey, thanks for a great library. I was trying to integrate it into my project. I use a wrapper ReactiveProvider<T> around DataProvider<T> for RAC Support. I have my ReactiveProviders in each viewModel, but networking is done elsewhere so I initiate another DataProvider and call setData(_:updateCache:context:) on that data provider, and the ReactiveProvider doesn't get the delegate call for update.

Is this expected behaviour? I saw another issue, is this related to that? https://github.com/linkedin/RocketData/issues/8

Here is the code for ReactiveProvider

class ReactiveProvider<M: SimpleModel> {
    private let provider = DataProvider<M>()

    let signal: Signal<M?, NoError>
    fileprivate let pipe: Observer<M?, NoError>

    init() {
        let (signal, pipe) = Signal<M?, NoError>.pipe()
        self.signal = signal
        self.pipe = pipe
        provider.delegate = self
    }

    func start(with cacheKey: CacheKey) {
        if provider.isPaused {
            provider.isPaused = false
        }
        provider.fetchDataFromCache(withCacheKey: cacheKey.key, context: cacheKey) {
            [weak self] model, error in
            self?.pipe.send(value: model)
        }
    }

    func pause() {
        provider.isPaused = true
    }
}

extension ReactiveProvider: DataProviderDelegate {
    func dataProviderHasUpdatedData<T>(_ dataProvider: DataProvider<T>,
                                    context: Any?) {
        guard let data = dataProvider.data as? M else {
            pipe.send(value: nil)
            return
        }

        pipe.send(value: data)
    }
}

and here is the code that sets the data (in networking part of the app, not in viewModel)

class CacheProvider {
    private var providers: [String: Any] = [:]

    func cache<T: SimpleModel>(object: T?, for key: CacheKey) {
        let provider: DataProvider<T>
        if let p = providers[key.key] as? DataProvider<T> {
            provider = p
        } else {
            provider = DataProvider<T>()
            providers[key.key] = provider
        }
        provider.setData(object, updateCache: true, context: key)
    }
}

This commit adds a Cartfile that specifies the dependency to ConsistencyManager-iOS. The pull request is depending on the ConsistencyManager-iOS-PR-32 which provides better Carthage support.

For now, I've specified any version of the consistency manager compatible with 2.0.0 but you should better specify the next (minor?) release version that contains the PR listed above (s.th. like 2.0.1 but that's up to you and how you like to version).

If you want, I could also add installation instructions for Carthage to the Readme.

Thanks!

Hello,

I'm encountering the following error when trying to install RocketData through Carthage in a brand new project. It's basically an empty folder with github "linkedin/RocketData" defined in a Cartfile.

2016-10-24 11:42:10.277 xcodebuild[74733:2842940] [MT] DVTAssertions: Warning in /Library/Caches/com.apple.xbs/Sources/IDEFrameworks/IDEFrameworks-11246/IDEFoundation/Execution/RunDestinations/IDERunDestination.m:201 Details: Unable to find platform for /Users/plivesey/Library/Developer/Xcode/DerivedData/ConsistencyManager-ezmcupkggqbxrkawtipbzcwqqolg/Build/Products/ConsistencyManager: Error Domain=DVTFoundationNSBundleAdditionsErrorDomain Code=1 "Couldn't find platform in Info.plist CFBundleSupportedPlatforms or binary for ConsistencyManager" UserInfo={NSLocalizedDescription=Couldn't find platform in Info.plist CFBundleSupportedPlatforms or binary for ConsistencyManager} Function: DVTPlatform *_IDEPlatformForPathRunnable(IDEPathRunnable *__strong) Thread: <NSThread: 0x7fa5afd13660>{number = 1, name = main} Please file a bug at http://bugreport.apple.com with this warning message and any useful information you can provide.

Hey, I have started using Rocket Data recently and faced this crash. Please help me to identify what is this issue:-

#0. Crashed: com.apple.main-thread
0  libswiftCore.dylib             0x1089ae5f0 swift_storeEnumTagSinglePayload + 36
1  RocketData                     0x107d3addc DataProvider.init(dataModelManager : DataModelManager) -> DataProvider<A> (DataProvider.swift:92)
2  HDCommons                      0x104b08bdc DataProvider.init() (CacheContextUtils.swift:38)
3  HDCommons                      0x104b07818 CaheContext.__allocating_init() (CacheContext.swift:87)
4  HDCommons                      0x104b0a75c specialized CachedAttributes.save<A>(value:) (CachedAttributes.swift:16)
5  ABCApp                        0x102845d68 specialized PatientConfigUsecase.(getConfig(parameters : [String : Any]?) -> Promise<PatientConfig>).(closure #1).(closure #1) (PatientConfigUsecase.swift:82)
6  ABCApp                        0x10284133c partial apply for PatientConfigUsecase.(getConfig(parameters : [String : Any]?) -> Promise<PatientConfig>).(closure #1).(closure #1) (PatientConfigUsecase.swift)
7  ABCApp                        0x1028413a0 DataResponse<PatientConfig> (PatientConfigUsecase.swift)
8  Alamofire                      0x102dae8fc closure #1 in closure #1 in DataRequest.response<A>(queue:responseSerializer:completionHandler:) + 156
9  Alamofire                      0x102db2a8c partial apply for closure #1 in closure #1 in DownloadRequest.response<A>(queue:responseSerializer:completionHandler:) + 44
10 Alamofire                      0x102d8e4c0 _T0Ieg_IeyB_TR (NetworkReachabilityManager.swift)
11 libdispatch.dylib              0x200dff6c8 _dispatch_call_block_and_release + 24
12 libdispatch.dylib              0x200e00484 _dispatch_client_callout + 16
13 libdispatch.dylib              0x200ddfb44 _dispatch_main_queue_callback_4CF$VARIANT$armv81 + 1012
14 CoreFoundation                 0x2013561bc __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
15 CoreFoundation                 0x201351084 __CFRunLoopRun + 1964
16 CoreFoundation                 0x2013505b8 CFRunLoopRunSpecific + 436
17 GraphicsServices               0x2035c4584 GSEventRunModal + 100
18 UIKitCore                      0x22e348bc8 UIApplicationMain + 212
19 ABCApp                        0x1027a5c54 main (AppDelegate.swift:69)
20 libdyld.dylib                  0x200e10b94 start + 4

Here's what I am struggling to get my head around. Suppose we have these models

struct User: Model {
    let id: Int
    let online: Bool
}

struct Message: Model {
   let id: Int
   let user: User
}

and CollectionDataProvider<Message>() in a view controller. AFAIU, Consistency manager only notifies CollectionDataProviderDelegate if CollectionDataProvider has been updated via set setData(). So far, so good.

Now I want my view controller to be notified if User model has been updated from somewhere else. As described here: https://github.com/plivesey/ConsistencyManager-iOS/#how-it-works

There seem to be no method listenForUpdates(self) in Consistency Manager. I presume it was replaced with addListener. But it sounds like I shouldn't use CM directly, because Rocket Data does it for us. The way it is done in my understanding is via DataProvider. Now in the example individual Message models are provided by CollectionDataProvider already. What is the correct approach to listen to User model updates, so that a corresponding Message can be refreshed in the view controller?

1. Creating a new DataProvider for each Message from the collection?
2. Creating a DataProvider for User in each Message?
3. Adding a listener using ConsistencyManager directly?

This scenario is mentioned in Peter's presentation and somewhere else, but I couldn't find a proper example or figure this out. Thanks.

In this pr, i do 2 things. The first one, I adapte the swift4 syntax to eliminate the warnings. The second one is performance improvement. Performance improvement as follow, when called dataHolder.setData(data, changeTime: ChangeTime()) method, if method return directly because of the conflict resolution mechanism，and code logic will continue to write data to the cache. In this case, it is unnecessary.

Hey, I noticed that you guys are actively adding Swift 3 support for ConsistencyManager-iOS.

Are you planning on adding Swift 3 support for RocketData? Do you need help with that? Or do you recommend using ConsistencyManager directly?

Hey there!

How can I ensure that every model is referencing a copy of the cached data?

For example, imagine Twitter, where each Tweet has a User.

struct Tweet {
  let id: String
  let user: User
}

struct User {
  let id: String
  let someRandomString = String.random() // For example purposes. :)
}

Now when importing from the API, each Tweet in the API response has a copy of its User, but on the iOS client we add a generated property (e.g. someRandomString) and cache this generated property. Every copy of User, even if they have the same modelIdentifier, will have a very different someRandomString value upon import since the value does not come from the server. Is there any way to "find or create" this data smartly?

So far I see two options:

1. Every time I create a user, fetch the copy in the cache manually and set someRandomString from cache without setting it locally. This is problematic since modelFromCache is async.
2. Call updateModel on the DataModelManager which will then let all instances of CollectionDataProvider know that a change has been made and to update from the cache (which will then force all copies of User to sync.)

Any other options/ideas?

Can you please do a new release for Cocoapods to update ConsistencyManager to the latest version? Version 5.1 has an important update, without it there is a crash in Swift 4.

Hey,

When a user logs out, I want to wipe everything so that cached items don't leak into the next session. I went through the docs but couldn't make out if this was supported?

When trying to start using this, you(me) get in the weeds pretty quick as you need to implement your own caching layer to begin using this.

It would be great if there was an example or few cache delegate implementations to reference or use to help people get started quicker. 😎

I see theres a note in the readme saying that currently only iOS platform is compiling for carthage. Is the reason already known? and is this being worked on? Besides that, any reason it wouldn't be compatible with mac catalyst? Thanks

It should be trivial to make data providers observable objects. Since the library promotes a one way data flow anyway, using it with SwiftUI seems natural.

Has anyone implemented RocketData with complex models and collection data providers other than LinkedIn? Can LinkedIn share or has any open source projects that demonstrate an app with complex data model?

First of all, thanks for the library.

I have two models, both conform to Model protocol:

public struct Person {
    public let id: String
    public let name: String
}

public struct Group {
    public let id: String
    public let persons: [Person]
}

I'm putting a group into the cache:

let person1 = Person(id: "1", name: "jj")
let person2 = Person(id: "2", name: "name")
let group = Group(id: "1", persons: [person1, person2])
let groupDataProvider = ModelDataProvider<Group>()
groupDataProvider.setData(group)

and then trying to take a person out of there:

let dataProvider = ModelDataProvider<Person>()
dataProvider.fetchDataFromCache(withCacheKey: person1.modelIdentifier) { (model, error) in
    if let error = error {
        print("error \(error)")
    } else {
        print("model \(model) \(type(of: model))")
    }
}

However, nil is returned. Looks like we're unable to get child objects out of cache?

When a user logs out, we need to purge but it doesn't seem that you guys support a complete purge...

Is this the only way?

// Purge let count = self?.usersDataProvider.count ?? 0 for index in stride(from: count, to: 0, by: -1) { self?.usersDataProvider.remove(at: index) }

When calling CollectionDataProvider.fetchDataFromCache, If there are no objects in the cache matching the cache key, nil is returned for the object array (I might prefer an empty array), but more importantly, the cache key is not set on the provider, so even though you have a delegate listening to the data provider, it will not get notified of subsequent additions to the collection. Here's the sequence I'm doing:

collectionDataProvider = CollectionDataProvider<StoreItemPendingPurchase>()
collectionDataProvider.delegate = self
collectionDataProvider.fetchDataFromCache(withCacheKey: cacheKey)

This returns nil for the error and nil for the object array. And the data provider's cacheKey is still nil. If somewhere else in the app someone sets data on the same cacheKey, I don't find out about it because my data provider's cacheKey is still nil.

Is this expected? If there some way to set the cacheKey independently of using setData() or fetchDataFromCache()?