Next Cookies
Tiny little function for getting cookies on both client & server with next.js.
This enables easy client-side and server-side rendering of pages that depend on cookies.
Installation
yarn add next-cookies
or
npm install --save next-cookies
Usage
Read all cookies:
const allCookies = cookies(ctx);
allCookies
will be an object with keys for each cookie.
The ctx
object is passed to your getInitialProps
function by next.js.
JSON is parsed automatically, to disable this behavior pass an options object with doNotParse
set to true
:
const allCookies = cookies(ctx, {doNotParse: true});
The options object is passed directly to the underlying universal-cookie library.
Read a single cookie:
const { myCookie } = cookies(ctx);
or
const myCookie = cookies(ctx).myCookie;
The ctx
object is passed to your getInitialProps
function by next.js.
Set a cookie:
This library does not support setting cookies. However, this is how to do it in client-side code:
document.cookie = `foo=bar; path=/`;
This sets a cookie named foo
to the value bar
.
The path
portion is optional but usually desired.
An expiration date may be appended (see below), otherwise the cookie will be deleted whenever the browser is closed.
Delete a cookie:
This library does not support deleting cookies. However, this is how to do it in client-side code:
document.cookie = `foo=; path=/; expires=Thu, 01 Jan 1970 00:00:01 GMT`;
The value doesn't matter, although the path
does. The expiration date must be in the past.
Complete Example
import React from 'react'
import cookies from 'next-cookies'
class NameForm extends React.Component {
static async getInitialProps(ctx) {
return {
initialName: cookies(ctx).name || ''
}
}
constructor(props) {
super(props);
this.state = {name: props.initialName || ''};
this.handleChange = this.handleChange.bind(this);
this.reset = this.reset.bind(this);
}
handleChange(event) {
const newName = event.target.value;
this.setState({name: newName});
document.cookie = `name=${newName}; path=/`;
}
reset() {
this.setState({name: ''});
document.cookie = 'name=; path=/; expires=Thu, 01 Jan 1970 00:00:01 GMT';
}
render() {
return (
<div>
<p>Hi {this.state.name}</p>
<p>Change cookie: <input
type="text"
placeholder="Your name here"
value={this.state.name}
onChange={this.handleChange}
/>!
</p>
<p>Delete cookie: <button onClick={this.reset}>Reset</button></p>
</div>
);
}
}
export default NameForm
See, also, the test app: https://github.com/matthewmueller/next-cookies/blob/master/tests/test-app/pages/cookies.js
More Information
- https://www.npmjs.com/package/universal-cookie
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies
- https://developer.mozilla.org/en-US/docs/Web/API/Document/cookie
- https://tools.ietf.org/html/rfc6265
License
MIT