Custom 404 / Error Page / Maintenance Page that is displayed whenever a bug is pushed or the app encounters and issue on boot

[Emad-Eldin-G]

Checklist

• I have searched the existing issues for similar feature requests.
• I added a descriptive title and summary to this issue.

Summary

I think this is definitely a useful feature if, for example:

• The developers want to some time down to work on a new feature or fix something
• A bug is accidentally pushed, instead of seeing the ugly error message, a nicer 404 page is presented

This is similar to something like this

Perhaps this could be implemented by checking for all errors before running script, but having it in its own command would be helpful.

Why?

No response

How?

Suggestions:

• st.default_error_page()
• st.default_maintenance_page()

Where these commands are on the top of the script, and can be turned on or off based on developer preference:

• st.default_error_page(some_error_page.py, true) - Params: custom_page(python script) which would link to the custom script written by the developer, always_on(boolean) would constantly intercept errors and show the default error page
• st.default_maintenance_page(some_error_page.py) - Params: custom_page(python script) which would link to the custom script written by the developer, similar to the error page command

Additional Context

No response

[github-actions]

To help Streamlit prioritize this feature, react with a 👍 (thumbs up emoji) to the initial post.

Your vote helps us identify which enhancements matter most to our users.