Skip to content

Contribute an alternative typing example for forms sample #24

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Jun 8, 2018
Merged

Contribute an alternative typing example for forms sample #24

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
d5b7133
Contribute an alternative typing example for forms sample
TomasHubelbauer Jun 8, 2018
1bc5838
shorten React.ChangeEventHandler example and move to discussion
swyxio Jun 8, 2018
4672769
Update README.md
swyxio Jun 8, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 15 additions & 1 deletion README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -369,7 +369,21 @@ class App extends React.Component<{}, { // no props
}
```

[Something to add? File an issue](https://github.com/sw-yx/react-typescript-cheatsheet/issues/new).
Instead of typing the arguments and return values with `React.FormEvent<>` and `void`, you may alternatively apply types to the event handler itself (*contributed by @TomasHubelbauer*):

```tsx
onChange: React.ChangeEventHandler<HTMLInputElement> = (e) => {
this.setState({text: e.currentTarget.value})
}
```

<details>

<summary><b>Discussion</b></summary>

Why two ways to do the same thing? The first method uses an inferred method signature `(e: React.FormEvent<HTMLInputElement>): void` and the second method enforces a type of the delegate provided by `@types/react`. So `React.ChangeEventHandler<>` is simply a "blessed" typing by `@types/react`, whereas you can think of the inferred method as more... *artisanally hand-rolled*. Either way it's a good pattern to know. [See our Github PR for more](https://github.com/sw-yx/react-typescript-cheatsheet/pull/24).

</details>

# Section 3: Advanced Guides

Expand Down