Include user locale to the Keycloak ID token

Question

I would like Keycloak (1.4.0) to include the users\' chosen locale to the ID token.

I have come as far as creating a user attribute mapper, which was supposed to map the

Answer 1

I suppose you already have something like this:

1. Open the admin console of your realm.
2. Go to Clients and select your client
3. This only works for Settings > Access Type confidential or public (not bearer-only)
4. Go to Mappers
5. Create a mapping from your attribute to json
6. Check "Add to ID token"

To access the mapped claim you use something like this:

final Principal userPrincipal = httpRequest.getUserPrincipal();

if (userPrincipal instanceof KeycloakPrincipal) {

    KeycloakPrincipal kp = (KeycloakPrincipal) userPrincipal;
    IDToken token = kp.getKeycloakSecurityContext().getIdToken();

    Map otherClaims = token.getOtherClaims();

    if (otherClaims.containsKey("YOUR_CLAIM_KEY")) {
        yourClaim = String.valueOf(otherClaims.get("YOUR_CLAIM_KEY"));
    }
} else {
    throw new RuntimeException(...);
}

Hope this helps and fits your use case. I used this for a custom attribute I added with a custom theme.