initial commit

routes/middleware.go

@@ -0,0 +1,97 @@
+package routes
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"foobar/views"
+	"net/http"
+
+	"github.com/a-h/templ"
+)
+
+type userError struct {
+	error
+	user string
+}
+
+type redirectURL string
+
+type postRouteRedirectFunc func(http.ResponseWriter, *http.Request) (redirectURL, error)
+
+type routeGetFunc func(http.ResponseWriter, *http.Request) (templ.Component, error)
+
+var (
+	errUser = errors.New("user error")
+)
+
+func newUserError(msg string) *userError {
+	return &userError{
+		user: msg,
+	}
+}
+
+func (u *userError) Error() string {
+	return u.user
+}
+
+func (u redirectURL) Valid() bool {
+	return len(u) > 0 && u[0] == '/'
+}
+
+func getRouteMiddleware(fun routeGetFunc) http.HandlerFunc {
+	// TODO: handle boosted HTMX requests gracefully
+	return func(w http.ResponseWriter, r *http.Request) {
+		component, err := fun(w, r)
+		if err != nil {
+			logInternalError(w, err)
+			return
+		}
+		err = component.Render(context.Background(), w)
+		if err != nil {
+			logInternalError(w, err)
+			return
+		}
+	}
+}
+
+func redirectHtmxFormMiddleware(fun postRouteRedirectFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+
+		hxRequest := r.Header.Get("HX-Request") == "true"
+
+		redirectURL, err := fun(w, r)
+		if err != nil {
+			w.Header().Add("HX-Retarget", "#error-target")
+			w.Header().Add("HX-Reswap", "innerHTML")
+			w.WriteHeader(http.StatusUnprocessableEntity)
+			if u, ok := err.(*userError); ok {
+				if hxRequest {
+					err = views.ErrorBox(u.user).Render(context.Background(), w)
+					if err != nil {
+						logError(fmt.Errorf("%w: %s", err, r.URL.Path))
+					}
+				} else {
+					_, _ = w.Write([]byte(u.user))
+
+				}
+				return
+			} else {
+				msg := "Internal error... See the server logs for more information"
+				_ = views.ErrorBox(msg).Render(context.Background(), w)
+				logError(err)
+				return
+			}
+		}
+
+		if !redirectURL.Valid() {
+			panic("not implemented")
+		}
+
+		if hxRequest {
+			w.Header().Add("HX-Redirect", string(redirectURL))
+		} else {
+			http.Redirect(w, r, string(redirectURL), http.StatusFound)
+		}
+	}
+}