[RFC] Show a banner with a warning on deploy previews

[cherniavskii]

What's the problem? 🤔

Sometimes we share deploy previews with our users to showcase the feature before it's released or to demonstrate a bugfix.

Users might get confused and expect the feature to be released publicly, which is not the case (I think @joserodolfofreitas mentioned that we had support requests regarding this).
Or they might find an old deployment preview URL in the issues, but the API has changed since.

What are the requirements? ❓

No response

What are our options? 💡

No response

Proposed solution 🟢

To avoid these confusions, we might want to add a warning for all deployment previews, similar to what we have on https://v4.mui.com/ to make it clear that this is a preview and some features might not be publicly released yet

Relevant resources/benchmarks 🔗

No response

[oliviertassinari]

• The problem described seems to impact https://github.com/mui/material-ui too, so I think an RFC to transfer there.
• I have seen @Janpot add this banner for the preview in toolpad in Add banner to the app when running in preview mode toolpad#608 and then remove them in Hide preview banner on deployed pages toolpad#630. It would be cool to update these PRs description to give more context on why :)

[Janpot]

It would be cool to update these PRs description to give more context on why

👍 done

[oliviertassinari]

Another example of another project doing this: https://github.com/react-bootstrap/react-bootstrap

https://deploy-preview-6378--react-bootstrap.netlify.app/getting-started/introduction

---

@Janpot Thanks, so these Toolpad PRs that I linked are not directly related to this RFC. I thought that the idea was to help the Toolpad community contributors when they open a Render preview deployment. But no, it's for the actual people using Toolpad when they are previewing their applications e.g.

https://master--toolpad.mui.com/app/cl42qt2jx01249xnr14xjce8b/preview