delay.js | delay javascript execution until element is in view | Runtime Evironment library

I'm pretty sure this is because you are defining a closure in a function component, and thus the closure is capturing a reference to the existing props at the time the closure was defined. See Dan Abramov's extensive post "The Complete Guide to useEffect" to better understand how closures and function components relate to each other.

As alternatives, you could move the polling logic out of the component and execute it in a thunk (where it has access to getState()), or use the useRef() hook to have a mutable value that could be accessed over time (and potentially use a useEffect() to store the latest props value in that ref after each re-render). There are probably existing hooks available that would do something similar to that useRef() approach as well.

You can make one of the following changes in order to fix the compilation issues.

• Invoke it using

You can have gravity.js listen to an event on window, and activate its code only when that event fires. When delay is finished, trigger that event, so that gravity.js sees it and starts running.

You will need Jquery in order for Bootstrap's javascript related features to function properly. I believe you only need Tether if you are using Bootstrap components like tooltips.

The order in application.js matters. Jquery, and Tether if you need it, needs to be loaded in before Bootstrap.

Recent releases of AngularFire require rxjs 6. Please upgrade rxjs and include rxjs-compat if you have dependencies that haven't upgraded.

As callback is (or must be) a function, you need to call it like this: callback(), you forgot the parenthesis.

First when you put a function with parenthesis as an argument to a big function, the argument function is executed before the big function.

FuncDelay(1000,Summ(3)) is transformed into FuncDelay(1000,undefined) before the functDelay is launched, beacause undefined is the return value of Summ. that explains why console.log(typeto callback) shows undefined.

You could get rid of the parenthesis so the argument will be the function and not the return of the function: FuncDelay(1000,Summ) but you obviously loose the argument 3 in it, so you need to create a function without any argument that holds your function with an argument. the quick notation is function(){Summ(3);}.