IIRC, O'Reilly's Safari Online did a good enough implementation that handled external authentication (using SAML with an IdP) and on-platform authentication (us

IIRC, O'Reilly's Safari Online did a good enough implementation that handled external authentication (using SAML with an IdP) and on-platform authentication (using email address and password). The login form had both the email and password fields, but once you typed your email address and tabbed to the password field, it would've detected at that time whether you're an SSO user who needs to be redirected to elsewhere for authentication, and if so, it would hide the password field and redirect you when you hit Enter or clicked the Submit button. This requires JavaScript to work, but seemed like a good enough compromise to support both modes. P.S.: It's been a long time since I used Safari Online. Hence the past tense in the description above. It probably still has the same behavior.