web/handlers: revamp error localization

fixes #66

go.mod

@@ -33,7 +33,7 @@ require (
 	go.cryptoscope.co/muxrpc/v2 v2.0.0-beta.1.0.20210308090127-5f1f5f9cbb59
 	go.cryptoscope.co/netwrap v0.1.1
 	go.cryptoscope.co/secretstream v1.2.2
-	go.mindeco.de v1.9.0
+	go.mindeco.de v1.10.0
 	go.mindeco.de/ssb-refs v0.1.1-0.20210108133850-cf1f44fea870
 	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad
 	golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9

go.sum

@@ -497,6 +497,8 @@ go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.etcd.io/etcd v0.0.0-20191023171146-3cf2f69b5738/go.mod h1:dnLIgRNXwCJa5e+c6mIZCrds/GIG4ncV9HhK5PX7jPg=
 go.mindeco.de v1.9.0 h1:/xli02DkzpIUZxp/rp1nj8z/OZ9MHvkMIr9TfDVcmBg=
 go.mindeco.de v1.9.0/go.mod h1:ePOcyktbpqzhMPRBDv2gUaDd3h8QtT+DUU1DK+VbQZE=
+go.mindeco.de v1.10.0 h1:H/bhL+dIgZZnUgBEDlKUJBisTszNiHDONeGZtGdiJJ0=
+go.mindeco.de v1.10.0/go.mod h1:ePOcyktbpqzhMPRBDv2gUaDd3h8QtT+DUU1DK+VbQZE=
 go.mindeco.de/ssb-refs v0.1.1-0.20210108133850-cf1f44fea870 h1:TCI3AefMAaOYECvppn30+CfEB0Fn8IES1SKvvacc3/c=
 go.mindeco.de/ssb-refs v0.1.1-0.20210108133850-cf1f44fea870/go.mod h1:OnBnV02ux4lLsZ39LID6yYLqSDp+dqTHb/3miYPkQFs=
 go.opencensus.io v0.20.1/go.mod h1:6WKK9ahsWS3RSO+PY9ZHZUfv2irvY6gN279GOPZjmmk=

web/errors/badrequest.go

@@ -34,3 +34,11 @@ func (f ErrForbidden) Error() string {
 }
 
 var ErrNotAuthorized = errors.New("rooms/web: not authorized")
+
+type PageNotFound struct {
+	Path string
+}
+
+func (e PageNotFound) Error() string {
+	return fmt.Sprintf("rooms/web: page not found: %s", e.Path)
+}

web/errors/errhandler.go

@@ -0,0 +1,93 @@
+package errors
+
+import (
+	"errors"
+	"html/template"
+	"net/http"
+
+	"github.com/go-kit/kit/log/level"
+	"go.mindeco.de/http/auth"
+	"go.mindeco.de/http/render"
+	"go.mindeco.de/logging"
+
+	"github.com/ssb-ngi-pointer/go-ssb-room/roomdb"
+	"github.com/ssb-ngi-pointer/go-ssb-room/web/i18n"
+)
+
+type ErrorHandler struct {
+	locHelper *i18n.Helper
+	render    *render.Renderer
+}
+
+func NewErrorHandler(locHelper *i18n.Helper) *ErrorHandler {
+	return &ErrorHandler{
+		locHelper: locHelper,
+	}
+}
+
+// SetRenderer needs to update the rendere later since we need to pass ErrorHandler into render.New (ie. befor we get the pointer for r)
+func (eh *ErrorHandler) SetRenderer(r *render.Renderer) {
+	eh.render = r
+}
+
+func (eh *ErrorHandler) Handle(rw http.ResponseWriter, req *http.Request, code int, err error) {
+	var ih = i18n.LocalizerFromRequest(eh.locHelper, req)
+
+	// default, unlocalized message
+	msg := err.Error()
+
+	// localize some specific error messages
+	var (
+		aa  roomdb.ErrAlreadyAdded
+		pnf PageNotFound
+		br  ErrBadRequest
+	)
+
+	switch {
+	case err == auth.ErrBadLogin:
+		msg = ih.LocalizeSimple("ErrorAuthBadLogin")
+
+	case errors.Is(err, roomdb.ErrNotFound):
+		msg = ih.LocalizeSimple("ErrorNotFound")
+
+	case errors.As(err, &aa):
+		msg = ih.LocalizeWithData("ErrorAlreadyAdded", map[string]string{
+			"Feed": aa.Ref.Ref(),
+		})
+
+	case errors.As(err, &pnf):
+		msg = ih.LocalizeWithData("ErrorPageNotFound", map[string]string{
+			"Path": pnf.Path,
+		})
+
+	case errors.As(err, &br):
+		// TODO: we could localize all the "Where:" as labels, too
+		// buttt it feels like overkill right now
+		msg = ih.LocalizeWithData("ErrorBadRequest", map[string]string{
+			"Where":   br.Where,
+			"Details": br.Details.Error(),
+		})
+	}
+
+	data := errorTemplateData{
+		Err: template.HTML(msg),
+		// TODO: localize status codes? might be fine with a few
+		Status:     http.StatusText(code),
+		StatusCode: code,
+	}
+
+	renderErr := eh.render.Render(rw, req, "error.tmpl", code, data)
+	if renderErr != nil {
+		logger := logging.FromContext(req.Context())
+		level.Error(logger).Log("event", "error template renderfailed",
+			"orig-err", err,
+			"render-err", renderErr,
+		)
+	}
+}
+
+type errorTemplateData struct {
+	StatusCode int
+	Status     string
+	Err        template.HTML
+}

web/handlers/http.go

@@ -3,7 +3,6 @@
 package handlers
 
 import (
-	"errors"
 	"fmt"
 	"html/template"
 	"net/http"
@@ -25,6 +24,7 @@ import (
 	"github.com/ssb-ngi-pointer/go-ssb-room/roomdb"
 	"github.com/ssb-ngi-pointer/go-ssb-room/roomstate"
 	"github.com/ssb-ngi-pointer/go-ssb-room/web"
+	weberrs "github.com/ssb-ngi-pointer/go-ssb-room/web/errors"
 	"github.com/ssb-ngi-pointer/go-ssb-room/web/handlers/admin"
 	roomsAuth "github.com/ssb-ngi-pointer/go-ssb-room/web/handlers/auth"
 	"github.com/ssb-ngi-pointer/go-ssb-room/web/i18n"
@@ -78,16 +78,23 @@ func New(
 		return nil, err
 	}
 
+	eh := weberrs.NewErrorHandler(locHelper)
+
+	allTheTemplates := concatTemplates(
+		HTMLTemplates,
+		roomsAuth.HTMLTemplates,
+		admin.HTMLTemplates,
+	)
+	allTheTemplates = append(allTheTemplates, "error.tmpl")
+
 	r, err := render.New(web.Templates,
 		render.SetLogger(logger),
 		render.BaseTemplates("base.tmpl", "menu.tmpl"),
-		render.AddTemplates(concatTemplates(
-			HTMLTemplates,
-			roomsAuth.HTMLTemplates,
-			admin.HTMLTemplates,
-		)...),
-		render.ErrorTemplate("error.tmpl"),
+		render.AddTemplates(allTheTemplates...),
+		// render.ErrorTemplate(),
+		render.SetErrorHandler(eh.Handle),
 		render.FuncMap(web.TemplateFuncs(m)),
+
 		// TODO: move these to the i18n helper pkg
 		render.InjectTemplateFunc("i18npl", func(r *http.Request) interface{} {
 			loc := i18n.LocalizerFromRequest(locHelper, r)
@@ -97,6 +104,7 @@ func New(
 			loc := i18n.LocalizerFromRequest(locHelper, r)
 			return loc.LocalizeSimple
 		}),
+
 		render.InjectTemplateFunc("current_page_is", func(r *http.Request) interface{} {
 			return func(routeName string) bool {
 				route := m.Get(routeName)
@@ -110,6 +118,7 @@ func New(
 				return r.RequestURI == url.Path
 			}
 		}),
+
 		render.InjectTemplateFunc("urlToNotice", func(r *http.Request) interface{} {
 			return func(name string) *url.URL {
 				noticeName := roomdb.PinnedNoticeName(name)
@@ -135,11 +144,13 @@ func New(
 				return u
 			}
 		}),
+
 		render.InjectTemplateFunc("is_logged_in", members.TemplateHelper()),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("web Handler: failed to create renderer: %w", err)
 	}
+	eh.SetRenderer(r)
 
 	cookieCodec, err := web.LoadOrCreateCookieSecrets(repo)
 	if err != nil {
@@ -154,52 +165,14 @@ func New(
 		},
 	}
 
-	// TODO: this is just the error handler for http/auth, not render
-	authErrH := func(rw http.ResponseWriter, req *http.Request, err error, code int) {
-		var ih = i18n.LocalizerFromRequest(locHelper, req)
-
-		// default, unlocalized message
-		msg := err.Error()
-
-		// localize some specific error messages
-		var (
-			aa roomdb.ErrAlreadyAdded
-		)
-		switch {
-		case err == auth.ErrBadLogin:
-			msg = ih.LocalizeSimple("AuthErrorBadLogin")
-
-		case errors.Is(err, roomdb.ErrNotFound):
-			msg = ih.LocalizeSimple("ErrorNotFound")
-
-		case errors.As(err, &aa):
-			msg = ih.LocalizeSimple("ErrorAlreadyAdded")
-		}
-
-		r.HTML("error.tmpl", func(rw http.ResponseWriter, req *http.Request) (interface{}, error) {
-			return errorTemplateData{
-				Err: msg,
-				// TODO: localize?
-				Status:     http.StatusText(code),
-				StatusCode: code,
-			}, nil
-		}).ServeHTTP(rw, req)
-	}
-
-	notAuthorizedH := r.HTML("error.tmpl", func(rw http.ResponseWriter, req *http.Request) (interface{}, error) {
-		statusCode := http.StatusUnauthorized
-		rw.WriteHeader(statusCode)
-		return errorTemplateData{
-			statusCode,
-			"Unauthorized",
-			"you are not authorized to access the requested site",
-		}, nil
-	})
-
 	authWithPassword, err := auth.NewHandler(dbs.AuthFallback,
 		auth.SetStore(cookieStore),
-		auth.SetErrorHandler(authErrH),
-		auth.SetNotAuthorizedHandler(notAuthorizedH),
+		auth.SetErrorHandler(func(rw http.ResponseWriter, req *http.Request, err error, code int) {
+			eh.Handle(rw, req, code, err)
+		}),
+		auth.SetNotAuthorizedHandler(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+			eh.Handle(rw, req, http.StatusForbidden, weberrs.ErrNotAuthorized)
+		})),
 		auth.SetLifetime(2*time.Hour), // TODO: configure
 	)
 	if err != nil {
@@ -237,16 +210,14 @@ func New(
 		bridge,
 	)
 
+	// auth routes
 	m.Get(router.AuthLogin).Handler(r.StaticHTML("auth/decide_method.tmpl"))
-
 	m.Get(router.AuthFallbackFinalize).HandlerFunc(authWithPassword.Authorize)
-
 	m.Get(router.AuthFallbackLogin).Handler(r.HTML("auth/fallback_sign_in.tmpl", func(w http.ResponseWriter, req *http.Request) (interface{}, error) {
 		return map[string]interface{}{
 			csrf.TemplateTag: csrf.TemplateField(req),
 		}, nil
 	}))
-
 	m.Get(router.AuthLogout).HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		err = authWithSSB.Logout(w, req)
 		if err != nil {
@@ -255,6 +226,7 @@ func New(
 		authWithPassword.Logout(w, req)
 	})
 
+	// all the admin routes
 	adminHandler := admin.Handler(
 		netInfo.Domain,
 		r,
@@ -271,7 +243,10 @@ func New(
 	)
 	mainMux.Handle("/admin/", members.AuthenticateFromContext(r)(adminHandler))
 
+	// landing page
 	m.Get(router.CompleteIndex).Handler(r.HTML("landing/index.tmpl", func(w http.ResponseWriter, req *http.Request) (interface{}, error) {
+		// TODO: try websocket upgrade (issue #)
+
 		notice, err := dbs.PinnedNotices.Get(req.Context(), roomdb.NoticeDescription, "en-GB")
 		if err != nil {
 			return nil, fmt.Errorf("failed to find description: %w", err)
@@ -286,13 +261,15 @@ func New(
 	}))
 	m.Get(router.CompleteAbout).Handler(r.StaticHTML("landing/about.tmpl"))
 
+	// notices (the mini-CMS)
 	var nh = noticeHandler{
 		notices: dbs.Notices,
 		pinned:  dbs.PinnedNotices,
 	}
 	m.Get(router.CompleteNoticeList).Handler(r.HTML("notice/list.tmpl", nh.list))
 	m.Get(router.CompleteNoticeShow).Handler(r.HTML("notice/show.tmpl", nh.show))
 
+	// public aliases
 	var ah = aliasHandler{
 		r: r,
 
@@ -303,6 +280,7 @@ func New(
 	}
 	m.Get(router.CompleteAliasResolve).HandlerFunc(ah.resolve)
 
+	//public invites
 	var ih = inviteHandler{
 		render: r,
 
@@ -317,14 +295,14 @@ func New(
 	m.Get(router.CompleteInviteInsertID).Handler(r.HTML("invite/insert-id.tmpl", ih.presentInsert))
 	m.Get(router.CompleteInviteConsume).HandlerFunc(ih.consume)
 
+	// statuc assets
 	m.PathPrefix("/assets/").Handler(http.StripPrefix("/assets/", http.FileServer(web.Assets)))
 
-	m.NotFoundHandler = r.HTML("error.tmpl", func(rw http.ResponseWriter, req *http.Request) (interface{}, error) {
-		rw.WriteHeader(http.StatusNotFound)
-		msg := i18n.LocalizerFromRequest(locHelper, req).LocalizeSimple("PageNotFound")
-		return errorTemplateData{http.StatusNotFound, "Not Found", msg}, nil
+	m.NotFoundHandler = http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		eh.Handle(rw, req, http.StatusNotFound, weberrs.PageNotFound{Path: req.URL.Path})
 	})
 
+	// hook up main stdlib mux to the gorrilla/mux with named routes
 	mainMux.Handle("/", m)
 
 	urlTo := web.NewURLTo(m)
@@ -363,13 +341,6 @@ func New(
 }
 
 // utils
-
-type errorTemplateData struct {
-	StatusCode int
-	Status     string
-	Err        string
-}
-
 func concatTemplates(lst ...[]string) []string {
 	var catted []string