Hide registration link if server doesn't support it

[thegcat]

We're hosting our own Riot in conjunction with a Synapse that doesn't allow registrations. It would be nice to be able to hide the registration link from the login page in that case.

[lampholder]

I think I'd rather this happened automatically based on the client's querying the server as to whether it allows registration (though this might require some rework of the login/registration UX to flow nicely).

[thegcat]

I'd be ok with it being automatic too :-D I thought this was the path of least resistance for now :-)

[hex-m]

Element 1.7.8 has a new option to disable registration in the UI.

  "settingDefaults": {
    "UIFeature.registration": false
  }

[t3chguy]

Synapse PR matrix-org/synapse#8867 which enables the client to probe the capability

[MadLittleMods]

Registration can be disabled on the login page with the config mentioned by @hex-m.

Other create account actions that link to the registration page are still visible though. I've created a separate issue (#24814) to track this since the issue description just mentions the login page which is solved.

[t3chguy]

@MadLittleMods this issue is "if the server doesn't support it" not if config.json says so

[weeman1337]

• O-Occasional because (new) users on a homeserver with registration disabled will see this
• S-Tolerable because they will see a message in the next screen
• X-Needs-Product because I think we should probably not just hide the button. Why not show a nice explanation screen? Thinking this from a perspective of a new user on a Matrix deployment: It currently only says „Registration disabled“. What should I do now? Better would be probably something „You cannot create an account by yourself on this homeserver. If you should have an account there, contact the support of your homeserver.“