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next.js/lib/utils.js
Tim Neutkens fb0b485299
Move out start method from server (#5315)
- This makes sure the Next.js renderer / server doesn't have a dependency on the `http` module.
- Splits out util functions for SSR only
- Removes obsolete methods / methods that weren't being tree-shaken
2018-09-27 21:10:53 +02:00

59 lines
1.5 KiB
JavaScript

export function execOnce (fn) {
let used = false
return (...args) => {
if (!used) {
used = true
fn.apply(this, args)
}
}
}
export function getDisplayName (Component) {
if (typeof Component === 'string') {
return Component
}
return Component.displayName || Component.name || 'Unknown'
}
export function isResSent (res) {
return res.finished || res.headersSent
}
export async function loadGetInitialProps (Component, ctx) {
if (process.env.NODE_ENV !== 'production') {
if (Component.prototype && Component.prototype.getInitialProps) {
const compName = getDisplayName(Component)
const message = `"${compName}.getInitialProps()" is defined as an instance method - visit https://err.sh/zeit/next.js/get-initial-props-as-an-instance-method for more information.`
throw new Error(message)
}
}
if (!Component.getInitialProps) return {}
const props = await Component.getInitialProps(ctx)
if (ctx.res && isResSent(ctx.res)) {
return props
}
if (!props) {
const compName = getDisplayName(Component)
const message = `"${compName}.getInitialProps()" should resolve to an object. But found "${props}" instead.`
throw new Error(message)
}
return props
}
export function getLocationOrigin () {
const { protocol, hostname, port } = window.location
return `${protocol}//${hostname}${port ? ':' + port : ''}`
}
export function getURL () {
const { href } = window.location
const origin = getLocationOrigin()
return href.substring(origin.length)
}