Rather than try to address your specific questions as other answers have already done, I’ll try to explain in simple terms the basics behind behaviors, and let you answer your own questions based on understanding those basics. A behavior is basically a message handling framework, where by “framework” I mean the classical definition of a … Read more
In Rails 5 you have to throw :abort otherwise it won’t work. (even returning false) Also, you should add prepend: true to the callback, to make sure it runs before the dependent: :destroy on the parent models. Something like this should work: class Something < ApplicationRecord before_destroy :can_destroy?, prepend: true private def can_destroy? if model.something? … Read more
From the Meteor.call documentation: On the client, if you do not pass a callback and you are not inside a stub, call will return undefined, and you will have no way to get the return value of the method. That is because the client doesn’t have fibers, so there is not actually any way it … Read more
The terminology here is a bit fuzzy. In general the two attempt to achieve similar results. In general, a callback is a function (or delegate) that you register with the API to be called at the appropriate time in the flow of processing (e.g to notify you that the processing is at a certain stage) … Read more
Short answer: For maximum flexibility, you can store the callback as a boxed FnMut object, with the callback setter generic on callback type. The code for this is shown in the last example in the answer. For a more detailed explanation, read on. “Function pointers”: callbacks as fn The closest equivalent of the C++ code … Read more
subscribe isn’t deprecated, only the variant you’re using is deprecated. In the future, subscribe will only take one argument: either the next handler (a function) or an observer object. So in your case you should use: .subscribe({ next: this.handleUpdateResponse.bind(this), error: this.handleError.bind(this) }); See these GitHub issues: https://github.com/ReactiveX/rxjs/pull/4202 https://github.com/ReactiveX/rxjs/issues/4159