Skip to content

Correctly load CSS files #9477

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

Closed
wants to merge 2 commits into from
Closed

Correctly load CSS files #9477

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
440234b
fix css file preloading for new css feature
robinweser Nov 20, 2019
4fa86d4
add proper css loading for page transitions
robinweser Nov 20, 2019
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
22 changes: 22 additions & 0 deletions packages/next/client/page-loader.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -103,6 +103,11 @@ export default class PageLoader {
!document.querySelector(`script[src^="${d}"]`)
) {
this.loadScript(d, route, false)
} else if (
/\.css$/.test(d) &&
!document.querySelector(`link[href^="${d}"]`)
) {
this.loadStylesheet(d)
}
})
this.loadRoute(route)
Expand All @@ -126,6 +131,14 @@ export default class PageLoader {
this.loadScript(url, route, true)
}

loadStylesheet(url) {
const link = document.createElement('link')
link.rel = 'stylesheet'
link.href = encodeURI(url)
link.as = 'style'
document.head.appendChild(link)
}

loadScript(url, route, isPage) {
const script = document.createElement('script')
if (process.env.__NEXT_MODERN_BUILD && 'noModule' in script) {
Expand Down Expand Up @@ -182,6 +195,15 @@ export default class PageLoader {

async prefetch(route, isDependency) {
route = this.normalizeRoute(route)

if (
/\.css$/.test(route) &&
!document.querySelector(`link[href^="${route}"]`)
) {
this.loadStylesheet(route)
Copy link
Member

@Timer Timer Nov 20, 2019 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Prefetching should be done via a real prefetch, i.e.:

<link rel="prefetch" href="/style.css" as="style" />

We probably need two different versions of the loadStylesheet method, similar to what we do for JS.

Copy link
Contributor Author

@robinweser robinweser Nov 21, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hmm, I've tried both preload and prefetch, but the browser (Safari) doesn't work as expected (checked preload/prefetch support before), so the only way to "preload" the CSS files would be the current loadStylesheet method.
Alternatively, we could just return blank on prefetching CSS and simply load it on page transition which seems to work without any FOUC or sth.

return
}

let scriptRoute = `${route === '/' ? '/index' : route}.js`

if (
Expand Down