Disabled workflows are indexed by search engines

[eatyourgreens]

Package

• app-project

Describe the bug

Disabled workflows, like Squirrel Mapper's Just Squirrels!, still send 200 responses, so are still available in search engines. When you click through to one, the classifier won't load, because the workflow isn't active. Visitors entering the page from a search engine won't be aware that there's a different workflow currently active.

To Reproduce

https://duckduckgo.com/?q=squirrel+mapper+zooniverse

Expected behavior

HTTP gives you a few response options for resources that aren't available any more, depending on whether the workflow is temporarily unavailable or permanently removed.

• 404: show a 404 page in the browser and remove this URL from search engine indexes.
• 300-series redirects: Redirect browsers to another page. Depending on the exact status code, may direct search engines to replace the current URL with the redirected URL.
• 200: continue to serve a page for the inactive workflow, but show user-friendly options in place of a broken classifier.

Additional context

Here are my notes, from 2021, about managing URLs.

• RFC: server-side routing, and SEO, for new classifier URLs #2446