Popper.js document is not defined with SSR

[MisterQH]

I need help with SSR using the Popper component.

When I access to my page via a link from another page, the page is rendered as it should be.

But when I try to access the same page directly from its url, I get an HTTP error 500 and this error message:

Error running template: ReferenceError: document is not defined
    at flipPlacement (/Users/xxx/Documents/dev/epotek/microservices/www/node_modules/@material-ui/core/Popper/Popper.js:37:52)
    at Object.Popper (/Users/xxx/Documents/dev/epotek/microservices/www/node_modules/@material-ui/core/Popper/Popper.js:112:22)
    at ReactDOMServerRenderer.render (/Users/xxx/Documents/dev/epotek/microservices/www/node_modules/react-dom/cjs/react-dom-server.node.development.js:3758:44)
    at ReactDOMServerRenderer.read (/Users/xxx/Documents/dev/epotek/microservices/www/node_modules/react-dom/cjs/react-dom-server.node.development.js:3538:29)
    at renderToString (/Users/xxx/Documents/dev/epotek/microservices/www/node_modules/react-dom/cjs/react-dom-server.node.development.js:4247:27)
    at Promise.asyncApply (imports/startup/server/ssr-server.js:33:5)
    at /Users/xxx/.meteor/packages/promise/.0.11.2.c7kmck.hukra++os+web.browser+web.browser.legacy+web.cordova/npm/node_modules/meteor-promise/fiber_pool.js:43:40

[oliviertassinari]

This concern is related to #15798 (comment). In this context, I would suggest this diff:

diff --git a/packages/material-ui/src/Popper/Popper.js b/packages/material-ui/src/Popper/Popper.js
index 80f5f9909..da7f77e6c 100644
--- a/packages/material-ui/src/Popper/Popper.js
+++ b/packages/material-ui/src/Popper/Popper.js
@@ -13,7 +13,7 @@ import ownerWindow from '../utils/ownerWindow';
  * @param {string} placement
  */
 function flipPlacement(placement) {
-  const direction = (typeof window !== 'undefined' && document.body.getAttribute('dir')) || 'ltr';
+  const direction = (typeof document !== 'undefined' && document.body.getAttribute('dir')) || 'ltr';

   if (direction !== 'rtl') {
     return placement;

Would it help in your case? (you likely shouldn't define a window on the server).
Alternatively, we could start to use canUseDOM, this would probably be a more resilient solution.

[MisterQH]

Yes thank you that fixed my issue !

[eps1lon]

I'm a bit concerned about branching this since it makes searching for these branches in the codebase very hard. Could you explain in which environment window is defined but not document?