Extracting i18n functionality to i18n core library (#16914)

* extracting i18n functionality to i18n core library

* Removing utils.T

* Adding documentation and changing one function name for better explanation

* Changing other missing utils.T

* Adding license string

* Renaming corelibs to pkg

* Renaming corelibs to pkg (moving directory)

* Renaming from pkg to shared

* Fixing bodyPage.Html casing

* Fixing merges

* Fixing merge problem

* Fixing tests

web/context.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mattermost/mattermost-server/v5/audit"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/shared/i18n"
 	"github.com/mattermost/mattermost-server/v5/utils"
 )
 
@@ -87,7 +88,7 @@ func (c *Context) LogAuditWithUserId(userId, extraInfo string) {
 
 func (c *Context) LogErrorByCode(err *model.AppError) {
 	code := err.StatusCode
-	msg := err.SystemMessage(utils.TDefault)
+	msg := err.SystemMessage(i18n.TDefault)
 	fields := []mlog.Field{
 		mlog.String("err_where", err.Where),
 		mlog.Int("http_code", err.StatusCode),

web/handlers.go

@@ -24,6 +24,7 @@ import (
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/services/tracing"
+	"github.com/mattermost/mattermost-server/v5/shared/i18n"
 	"github.com/mattermost/mattermost-server/v5/store/opentracinglayer"
 	"github.com/mattermost/mattermost-server/v5/utils"
 )
@@ -108,7 +109,7 @@ func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	)
 	c.App.InitServer()
 
-	t, _ := utils.GetTranslationsAndLocale(r)
+	t, _ := i18n.GetTranslationsAndLocaleFromRequest(r)
 	c.App.SetT(t)
 	c.App.SetRequestId(requestID)
 	c.App.SetIpAddress(utils.GetIPAddress(r, c.App.Config().ServiceSettings.TrustedProxyIPHeader))

web/oauth.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mattermost/mattermost-server/v5/audit"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/shared/i18n"
 	"github.com/mattermost/mattermost-server/v5/utils"
 	"github.com/mattermost/mattermost-server/v5/utils/fileutils"
 )
@@ -147,7 +148,7 @@ func authorizeOAuthPage(c *Context, w http.ResponseWriter, r *http.Request) {
 		utils.RenderWebError(c.App.Config(), w, r, err.StatusCode,
 			url.Values{
 				"type":    []string{"oauth_invalid_redirect_url"},
-				"message": []string{utils.T("api.oauth.allow_oauth.redirect_callback.app_error")},
+				"message": []string{i18n.T("api.oauth.allow_oauth.redirect_callback.app_error")},
 			}, c.App.AsymmetricSigningKey())
 		return
 	}
@@ -414,7 +415,7 @@ func signupWithOAuth(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	if !*c.App.Config().TeamSettings.EnableUserCreation {
 		utils.RenderWebError(c.App.Config(), w, r, http.StatusBadRequest, url.Values{
-			"message": []string{utils.T("api.oauth.singup_with_oauth.disabled.app_error")},
+			"message": []string{i18n.T("api.oauth.singup_with_oauth.disabled.app_error")},
 		}, c.App.AsymmetricSigningKey())
 		return
 	}

web/oauth_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/mattermost/mattermost-server/v5/einterfaces"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/shared/i18n"
 	"github.com/mattermost/mattermost-server/v5/utils"
 )
 
@@ -534,7 +535,7 @@ func TestOAuthComplete_ErrorMessages(t *testing.T) {
 		},
 	}
 
-	translationFunc := utils.GetUserTranslations("en")
+	translationFunc := i18n.GetUserTranslations("en")
 	c.App.SetT(translationFunc)
 	buffer := &bytes.Buffer{}
 	c.Logger = mlog.NewTestingLogger(t, buffer)