reactive-programming

问题 I need some help in implementing parallel asynchronous calls in RxJava. I have picked up a simple use case wherein the FIRST call fetches (rather searches) a list of products (Tile) to be displayed. The subsequent calls go out and fetch (A) REVIEWS and (B) PRODUCT IMAGES After several attempts I got to this place. 1 Observable<Tile> searchTile = searchServiceClient.getSearchResults(searchTerm); 2 List<Tile> allTiles = new ArrayList<Tile>(); 3 ClientResponse response = new ClientResponse(); 4

问题 I\'ve been looking to understand those 3: Subject , Behavior subject and Replay subject . I would like to use them and know when and why, what are the benefits of using them and although I\'ve read the documentation, watched tutorials and searched google I\'ve failed to make any sense of this. So what are their purpose? A real-world case would be most appreciated it does not have to even code. I would prefer a clean explanation not just \"a+b => c you are subscribed to ....\" Thank you 回答1:

问题 I read the Shiny documentation about reactive programming a few times now, but I can\'t properly understand the difference between observeEvent and eventReactive . The documentation says: Use observeEvent whenever you want to perform an action in response to an event. (Note that \"recalculate a value\" does not generally count as performing an action–see eventReactive for that.) .... Use eventReactive to create a calculated value that only updates in response to an event. This is just like a

问题 I would like to create dynamic tabs, where each time the user clicks a button, a new tab would be created. Each tab has the same content, with a variety of widgets that the user can use to select which sets of data to be plotted. Currently, I am using the solution here to dynamically create my tabs, but with the change that lapply is calling a function that calls tabPanel and adds content to the tabs ` renderUI({ some_data <- # Dataframe that data is extracted goes here createTabs <- function

问题 Can someone give a clear definition together with a simple example that explains what is a \"callback hell\" for someone who does not know JavaScript and node.js ? When (in what kind of settings) does the \"callback hell problem\" occur? Why does it occur? Is \"callback hell\" always related to asynchronous computations? Or can \"callback hell\" occur also in a single threaded application? I took the Reactive Course at Coursera and Erik Meijer said in one of his lectures that RX solves the

问题 Locked . This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. I\'ve read the Wikipedia article on reactive programming. I\'ve also read the small article on functional reactive programming. The descriptions are quite abstract. What does functional reactive programming (FRP) mean in practice? What does reactive programming (as opposed to non-reactive programming?) consist of? My

问题 I reviewed the following SO question: What are the Hot and Cold observables? To summarize: a cold observable emits its values when it has an observer to consume them, i.e. the sequence of values received by observers is independent of time of subscription. All observers will consume the same sequence of values. a hot observable emits value independently of its subscriptions, i.e. the values received by observers are a function of the time of subscription. Yet, I feel like hot vs. cold is