ADR-002: Both felogin Extension and Standalone Plugin 

Context 

TYPO3 frontend login is typically handled by ext:felogin. The question is how nr_passkeys_fe integrates its passkey login UI with the existing login flow.

Three approaches were considered:

A. Extend felogin only — Inject via ModifyLoginFormViewEvent B. Own Extbase plugin only — Independent login plugin C. Both — felogin integration AND standalone plugin

Decision 

Option C: Both felogin extension and standalone plugin.

• felogin integration: PSR-14 listener on ModifyLoginFormViewEvent injects a passkey login button into the existing felogin form.  50 lines of code.
• Standalone plugin: PasskeyLoginPlugin (Extbase) that can be placed on any page independently of felogin.

Consequences 

Positive:

• Sites using felogin get seamless integration with zero template changes
• New sites can use the standalone plugin without felogin dependency
• Mirrors nr-passkeys-be pattern (injects into BE login + provides own UI)
• Minimal code overhead ( 50 lines for felogin hook)

Negative:

• Two login UI paths to maintain and test
• Potential confusion for integrators ("which one do I use?")

Mitigation:

• Clear documentation: "Using felogin? It just works. Custom login? Use the plugin."
• Shared Fluid partials between both paths to minimize template duplication

Alternatives Considered 

Option A (felogin only): Would exclude sites not using felogin. Some TYPO3 installations use custom login forms or third-party login extensions.

Option B (Standalone only): Would force felogin users to add a second plugin alongside felogin, creating an awkward dual-form UX.