Adding React to a Vanilla Parcel Project

Create a Broadcaster in React with useState and useEffect Hooks

Create a Custom useBroadcaster Hook

Pass a Listener to a useCallback Hook

Create a Custom useListener Hook Around useCallback

Explaining the useListener Code

Map a Sequence of Values in React with useBroadcaster

Handling an Enter Keypress with useListener and React

Map a Sequence Based on Input Text in React

Creating a Debounce Operator to Limit Listener Calls

Wrap Fetch in a Broadcaster in React

Cancel a Fetch Request with a Broadcaster and React

Map an Error to a Broadcaster Value in React

Bringing the Pattern into React

All broadcasters need a way to be canceled. To cancel a fetch, we'll need to add an AbortController. This lesson walks through putting the pieces together to cancel our getUrl broadcaster.

Instructor: [0:00] What we also have to do is find how we can set this up to cancel because we do need cancellation behavior with every broadcaster we create. With promises, we use AbortControllers. I'll create a new AbortController(). This is an object that has a signal on it. If I say controller.signal here and grab a signal, I can pass that signal into the config of the fetch.

[0:30] When I do this, it allows this controller to abort my fetch, meaning, from this cancellation function I'm returning, I would say, controller.abort(), and this would tell this signal to control this fetch and cancel it.

[0:48] If instead of console.log(cancel), I invoke cancel, I'll hit Save here and you'll see that I aborted that request. If I comment this out, hit Save, you'll see it goes through just fine. If I uncomment it, I successfully abort the request.

Course

Bringing the Pattern into React

Cancel a Fetch Request with a Broadcaster and React

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