But either way, if we pick it up and look at it, what we have is not the thing inside of of it in our hands, but it’s just the wrapped box itself. It could also have something inside of it. A rather cruel gift to give someone on their birthday, but it’s possible to do. The box the gift comes in, wrapped up in some paper with pretty balloons on it, could actually be empty. You can think of optionals like a birthday gift. This is because the value is still “wrapped” inside of the optional. Honestly, if it weren’t for code completion this would be rather hard to find, but here’s how it looks in code: ().Note that instead of just getting the string "Blue", we get Optional("Blue"). From there we can connect to the timer publisher, and ask it to cancel itself. You see, the timer property we made is an autoconnected publisher, so we need to go to its upstream publisher to find the timer itself. Speaking of stopping the timer, it takes a little digging to stop the one we created. That will print the time every second until the timer is finally stopped. This accepts a publisher as its first parameter and a function to run as its second, and it will make sure that function is called whenever the publisher sends its change notification.įor our timer example, we could receive its notifications like this: Text("Hello, World!") In the case of regular publishers like this one, we need to catch the announcements by hand using a new modifier called onReceive(). If you remember, back in project 7 I said “ is more or less half of – it sends change announcements that something else can monitor.
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