WeatherDisplay | Get and display Open Weather Network weather

You are passing weather.current as props. While the child component is expecting weather as prop. So, what you end up doing is weather.current.current.temperature which is undefined because it doesn't exist. Just pass weather to the child prop.

Make this change when calling your child component.

Mixed params and hooks.

If you set as below

I think a little explanation about how Android runs your code might help.

So in the background, Android is running some code in an endless loop. Part of that loop is to check a message queue, which is basically where tasks get delivered - code it needs to execute. Ideally it will get all the work required in each loop finished quickly enough that it can manage 60 loops per second. If it has too much to do, that's where it starts to slow down and feel janky.

Some of the tasks that might get executed are things like an Activity being created, so it might want the system to run its onCreate code - which happens once for each Activity. You've probably noticed it only happens once, and that's where you've put your endless loop, right? To kind of trap the execution in there, until the AsyncTask delivers its result?

The problem is you're stopping the main loop from working - it can't move on and do anything until it's finished that task, and you're blocking it on purpose. That's very bad in general, and it's why you're encouraged not to do slow operations on that main thread (the one that runs the main looper) - it creates work that takes too long, and makes the whole UI less responsive (UI handling is also tasks that need to run)

So that's bad in general, but the way AsyncTasks actually work is they run on another thread (so they're not blocking the main one, it's like having another independent person working on stuff) - but they deliver the result on the main thread. They post a message to the main thread's message queue, telling it to run the onPostExecute code.

But the system can't get to that message until it's handled the earlier tasks in the queue. And if it's busy running an endless loop waiting for the result of the AsyncTask, it will never get to that message, the variable will never be updated, and the loop will never see the change it's waiting for. It's like someone holding up a line, refusing to move until they see something that someone further down the line is trying to deliver

That's a bunch of background, but the point is you shouldn't ever block a thread like that, unless it's a special thread you created so you know it's ok and it's not interfering with anything else. Think of Android more as an event-driven system - you write code that should be executed when something happens, like when an Activity gets created (ònCreate) or when a button is pressed(onClick) or when an AsyncTask completes (onPostExecute). There's a reason all these methods start with "on"! "When a thing happens, do this..."

So when your task completes, it runs onPostExecute and that's where all your code to handle receiving the result should go. It doesn't literally need to be inside the onPostExecute method - like you've put yours inside a passJSONGet method to keep things organised, but that gets called from onPostExecute, that's the event that triggers the code being run.

So whatever you need to do with the result, call it from onPostExecute. When that happens, it will do the stuff you've told it to do. Update a variable, make a toast, populate views in your layout with some new data, whatever!

You need to change a couple things. First, you are using NSData. You should be using the Swift type Data. To convert from NSData? to Data?, just add as Data? to the end of the variable declaration.

Also, Your type is optional, but you can't pass in an optional type, so you need to unwrap it (using, in this example, if let data = data { /* stuff here */}):

Create a function in the parent component and pass it down to the child component as a prop. Like:

Child Component:

You're problem is likely with this line:

Change your component like this.

In order to achieve your goal you have to do following:

1. Add identifier (id attribute, name attribute) to each of your checkbox
2. Change your isChecked state to an checkedItems array
3. Change your onChange logic to