fix(login): allow setting language on registered users (#4862)

* fix: user language for notifications

* fix(login): allow setting language on registered users

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/api/ui/login/external_login_handler.go

@@ -11,6 +11,7 @@ import (
 	"github.com/zitadel/oidc/v2/pkg/client/rp"
 	"github.com/zitadel/oidc/v2/pkg/oidc"
 	"golang.org/x/oauth2"
+	"golang.org/x/text/language"
 
 	"github.com/zitadel/zitadel/internal/api/authz"
 	http_mw "github.com/zitadel/zitadel/internal/api/http/middleware"
@@ -314,7 +315,12 @@ func (l *Login) renderExternalNotFoundOption(w http.ResponseWriter, r *http.Requ
 		data.ExternalPhone = human.PhoneNumber
 		data.ExternalPhoneVerified = human.IsPhoneVerified
 	}
-	l.renderer.RenderTemplate(w, r, translator, l.renderer.Templates[tmplExternalNotFoundOption], data, nil)
+	funcs := map[string]interface{}{
+		"selectedLanguage": func(l string) bool {
+			return data.Language == l
+		},
+	}
+	l.renderer.RenderTemplate(w, r, translator, l.renderer.Templates[tmplExternalNotFoundOption], data, funcs)
 }
 
 func (l *Login) handleExternalNotFoundOptionCheck(w http.ResponseWriter, r *http.Request) {
@@ -420,6 +426,7 @@ func (l *Login) mapExternalNotFoundOptionFormDataToLoginUser(formData *externalN
 		IsEmailVerified:   isEmailVerified,
 		Phone:             formData.Phone,
 		IsPhoneVerified:   isPhoneVerified,
+		PreferredLanguage: language.Make(formData.Language),
 	}
 }
 
@@ -445,6 +452,7 @@ func (l *Login) mapTokenToLoginUser(tokens *oidc.Tokens, idpConfig *iam_model.ID
 		NickName:          tokens.IDTokenClaims.GetNickname(),
 		Email:             tokens.IDTokenClaims.GetEmail(),
 		IsEmailVerified:   tokens.IDTokenClaims.IsEmailVerified(),
+		PreferredLanguage: tokens.IDTokenClaims.GetLocale(),
 	}
 
 	if tokens.IDTokenClaims.GetPhoneNumber() != "" {

internal/api/ui/login/external_register_handler.go

@@ -219,7 +219,13 @@ func (l *Login) renderExternalRegisterOverview(w http.ResponseWriter, r *http.Re
 	data.Phone = externalUser.Phone
 	data.ExternalPhone = externalUser.Phone
 	data.ExternalPhoneVerified = externalUser.IsPhoneVerified
-	l.renderer.RenderTemplate(w, r, translator, l.renderer.Templates[tmplExternalRegisterOverview], data, nil)
+
+	funcs := map[string]interface{}{
+		"selectedLanguage": func(l string) bool {
+			return data.Language == l
+		},
+	}
+	l.renderer.RenderTemplate(w, r, translator, l.renderer.Templates[tmplExternalRegisterOverview], data, funcs)
 }
 
 func (l *Login) handleExternalRegisterCheck(w http.ResponseWriter, r *http.Request) {
@@ -262,6 +268,7 @@ func (l *Login) mapTokenToLoginHumanAndExternalIDP(tokens *oidc.Tokens, idpConfi
 		NickName:          tokens.IDTokenClaims.GetNickname(),
 		Email:             tokens.IDTokenClaims.GetEmail(),
 		IsEmailVerified:   tokens.IDTokenClaims.IsEmailVerified(),
+		PreferredLanguage: tokens.IDTokenClaims.GetLocale(),
 	}
 
 	if tokens.IDTokenClaims.GetPhoneNumber() != "" {

internal/api/ui/login/register_handler.go

@@ -21,7 +21,6 @@ type registerFormData struct {
 	Firstname    string `schema:"firstname"`
 	Lastname     string `schema:"lastname"`
 	Language     string `schema:"language"`
-	Gender       int32  `schema:"gender"`
 	Password     string `schema:"register-password"`
 	Password2    string `schema:"register-password-confirmation"`
 	TermsConfirm bool   `schema:"terms-confirm"`
@@ -167,12 +166,6 @@ func (l *Login) renderRegister(w http.ResponseWriter, r *http.Request, authReque
 			}
 			return formData.Language == l
 		},
-		"selectedGender": func(g int32) bool {
-			if formData == nil {
-				return false
-			}
-			return formData.Gender == g
-		},
 	}
 	if authRequest == nil {
 		l.customTexts(r.Context(), translator, resourceOwner)
@@ -187,7 +180,6 @@ func (d registerFormData) toHumanDomain() *domain.Human {
 			FirstName:         d.Firstname,
 			LastName:          d.Lastname,
 			PreferredLanguage: language.Make(d.Language),
-			Gender:            domain.Gender(d.Gender),
 		},
 		Password: &domain.Password{
 			SecretString: d.Password,

internal/api/ui/login/static/templates/register.html

@@ -16,6 +16,7 @@
     {{ .CSRF }}
 
     <input type="hidden" name="authRequestID" value="{{ .AuthReqID }}" />
+    <input type="hidden" name="language" value="{{.Language}}" />
 
     <div class="lgn-register">