combine

问题 I found this question SwiftUI: Putting multiple BindableObjects into Envionment the answer said environmentObject(ObservableObject) returns modified view, therefore I can make call chain for multiple environmentObject. like let rootView = ContentView() .environmentObject(firstBindable) .environmentObject(secondBindable) and I wonder what is result if firstBindable and secondBindable are same type. how .environmentObject() knows what is exect value which is a programmer intended to set between

问题 I found this question SwiftUI: Putting multiple BindableObjects into Envionment the answer said environmentObject(ObservableObject) returns modified view, therefore I can make call chain for multiple environmentObject. like let rootView = ContentView() .environmentObject(firstBindable) .environmentObject(secondBindable) and I wonder what is result if firstBindable and secondBindable are same type. how .environmentObject() knows what is exect value which is a programmer intended to set between

问题 I want to achieve the following: Whenever someone triggers a CoreData save (ie. NSManagedObjectContextDidSave notification gets sent), I'd like to perform some background calculation based the changed NSManagedObject. Concrete example: Assume in a notes app, I want to asynchronously calculate the total number of words in all notes. The problem currently lies with the fact that NSManagedObject context is explicitly bound to thread and you are discouraged from using NSManagedObject s outside

问题 I want to achieve the following: Whenever someone triggers a CoreData save (ie. NSManagedObjectContextDidSave notification gets sent), I'd like to perform some background calculation based the changed NSManagedObject. Concrete example: Assume in a notes app, I want to asynchronously calculate the total number of words in all notes. The problem currently lies with the fact that NSManagedObject context is explicitly bound to thread and you are discouraged from using NSManagedObject s outside

问题 I want to achieve the following: Whenever someone triggers a CoreData save (ie. NSManagedObjectContextDidSave notification gets sent), I'd like to perform some background calculation based the changed NSManagedObject. Concrete example: Assume in a notes app, I want to asynchronously calculate the total number of words in all notes. The problem currently lies with the fact that NSManagedObject context is explicitly bound to thread and you are discouraged from using NSManagedObject s outside

问题 I'm wondering if there is a way to implement reconnection mechanism with new Apple framework Combine and use of URLSession publisher tried to find some examples in WWDC 2019 tried to play with waitsForConnectivity with no luck (it even not calling delegate on custom session) tried URLSession.background but it crashed during publishing. I'm also not understanding how do we track progress in this way Does anyone already tried to do smth like this? upd: It seems like waitsForConnectivity is not

问题 I'm wondering if there is a way to implement reconnection mechanism with new Apple framework Combine and use of URLSession publisher tried to find some examples in WWDC 2019 tried to play with waitsForConnectivity with no luck (it even not calling delegate on custom session) tried URLSession.background but it crashed during publishing. I'm also not understanding how do we track progress in this way Does anyone already tried to do smth like this? upd: It seems like waitsForConnectivity is not

问题 I'm trying to write some unit tests for my API using URLSession.DataTaskPublisher. I've found an already existing question on Stackoverflow for the same but I'm struggling to implement a working class using the proposed solution. Here's the existing question: How to mock URLSession.DataTaskPublisher protocol APIDataTaskPublisher { func dataTaskPublisher(for request: URLRequest) -> URLSession.DataTaskPublisher } class APISessionDataTaskPublisher: APIDataTaskPublisher { func dataTaskPublisher

问题 I'm using a dataTaskPublisher to fetch some data: func downloadData(_ req: URLRequest) { self.cancelToken = dataTaskPublisher(for: req).sink { /* ... */ } } If the function is called while the request is in progress, I would like to return. Currently I either: 1. Set the cancelToken to nil in the sink or 2. Crate and manage a isDownloading variable. Is there a built-in way to check if the dataTaskPublisher is running (and optionally its progress)? 回答1: I mostly agree with @Rob, however you

问题 I'm trying to perform side effect on Publisher , and I can't find any operator which will allow me to do something like this. To be precise, I'm looking for a concept similar to RxSwift's do(on:) . Here's what I'm trying to do. I'm writing a reactive wrapper for a delegate provided by a 3rd party SDK. It's and SDK for interacting with BLE devices. I have methods like startScanning and stopScanning and what I want to achieve is to react to signals and call stopScanning as a side effect of any