Centralizing error handling to a helpers package

cmd/web/main.go

@@ -5,10 +5,12 @@ import (
 	"fmt"
 	"go-udemy-web-1/internal/config"
 	"go-udemy-web-1/internal/handlers"
+	"go-udemy-web-1/internal/helpers"
 	"go-udemy-web-1/internal/models"
 	"go-udemy-web-1/internal/render"
 	"log"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/alexedwards/scs/v2"
@@ -19,6 +21,8 @@ const portNumber = ":8080"
 var (
 	app      config.AppConfig
 	session  *scs.SessionManager
+	infoLog  *log.Logger
+	errorLog *log.Logger
 )
 
 // main is the main application function
@@ -61,8 +65,15 @@ func run() error {
 	app.TemplateCahce = tc
 	app.UseCache = false
 
+	infoLog = log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
+	app.InfoLog = infoLog
+
+	errorLog = log.New(os.Stdout, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
+	app.ErrorLog = errorLog
+
 	repo := handlers.NewRepo(&app)
 	handlers.NewHandlers(repo)
+	helpers.NewHelpers(&app)
 
 	render.NewTemplates(&app)
 	return nil

internal/config/config.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"html/template"
+	"log"
 
 	"github.com/alexedwards/scs/v2"
 )
@@ -11,5 +12,7 @@ type AppConfig struct {
 	TemplateCahce map[string]*template.Template
 	UseCache      bool
 	InProduction  bool
+	InfoLog       *log.Logger
+	ErrorLog      *log.Logger
 	Session       *scs.SessionManager
 }

internal/handlers/handlers.go

@@ -5,9 +5,9 @@ import (
 	"fmt"
 	"go-udemy-web-1/internal/config"
 	"go-udemy-web-1/internal/forms"
+	"go-udemy-web-1/internal/helpers"
 	"go-udemy-web-1/internal/models"
 	"go-udemy-web-1/internal/render"
-	"log"
 	"net/http"
 )
 
@@ -33,23 +33,13 @@ func NewHandlers(r *Repository) {
 
 // Home is the home page handler
 func (m *Repository) Home(w http.ResponseWriter, r *http.Request) {
-	remoteIP := r.RemoteAddr
-	m.App.Session.Put(r.Context(), "remote_ip", remoteIP)
-
 	render.RenderTemplate(w, r, "home.page.tmpl", &models.TemplateData{})
 }
 
 // About is the about page handler
 func (m *Repository) About(w http.ResponseWriter, r *http.Request) {
-	// perform some logic
-	stringMap := make(map[string]string)
-	stringMap["test"] = "Hello world!"
-
-	remoteIP := m.App.Session.GetString(r.Context(), "remote_ip")
-	stringMap["remote_ip"] = remoteIP
-
 	// send the data to the template
-	render.RenderTemplate(w, r, "about.page.tmpl", &models.TemplateData{StringMap: stringMap})
+	render.RenderTemplate(w, r, "about.page.tmpl", &models.TemplateData{})
 }
 
 // Contact is the contact page handler
@@ -86,7 +76,7 @@ func (m *Repository) MakeReservation(w http.ResponseWriter, r *http.Request) {
 func (m *Repository) PostMakeReservation(w http.ResponseWriter, r *http.Request) {
 	err := r.ParseForm()
 	if err != nil {
-		log.Println(err)
+		helpers.ServerError(w, err)
 		return
 	}
 
@@ -123,7 +113,7 @@ func (m *Repository) PostMakeReservation(w http.ResponseWriter, r *http.Request)
 func (m *Repository) ReservationSummary(w http.ResponseWriter, r *http.Request) {
 	reservation, ok := m.App.Session.Get(r.Context(), "reservation").(models.Reservation)
 	if !ok {
-		log.Println("connot get item from reservation")
+		m.App.ErrorLog.Println("connot get item from session")
 		m.App.Session.Put(r.Context(), "error", "Can't get reservation from session")
 		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
 	}
@@ -164,7 +154,8 @@ func (m *Repository) AvailabilityJSON(w http.ResponseWriter, r *http.Request) {
 
 	out, err := json.MarshalIndent(resp, "", "    ")
 	if err != nil {
-		log.Println(err)
+		helpers.ServerError(w, err)
+		return
 	}
 
 	w.Header().Set("Content-Type", "application/json")

internal/handlers/setup_test.go

@@ -9,6 +9,7 @@ import (
 	"html/template"
 	"log"
 	"net/http"
+	"os"
 	"path/filepath"
 	"time"
 
@@ -45,6 +46,12 @@ func getRoutes() http.Handler {
 	app.TemplateCahce = tc
 	app.UseCache = true // Not to use ./templates
 
+	infoLog := log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
+	app.InfoLog = infoLog
+
+	errorLog := log.New(os.Stdout, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
+	app.ErrorLog = errorLog
+
 	repo := NewRepo(&app)
 	NewHandlers(repo)
 

internal/helpers/helpers.go

@@ -0,0 +1,26 @@
+package helpers
+
+import (
+	"fmt"
+	"go-udemy-web-1/internal/config"
+	"net/http"
+	"runtime/debug"
+)
+
+var app *config.AppConfig
+
+// NewHelpers sets up app config for helpers
+func NewHelpers(a *config.AppConfig) {
+	app = a
+}
+
+func ClientError(w http.ResponseWriter, status int) {
+	app.InfoLog.Println("Client error with status of", status)
+	http.Error(w, http.StatusText(status), status)
+}
+
+func ServerError(w http.ResponseWriter, err error) {
+	trace := fmt.Sprintf("%s\n%s", err.Error(), debug.Stack())
+	app.ErrorLog.Println(trace)
+	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+}

internal/render/render.go

@@ -5,9 +5,9 @@ import (
 	"errors"
 	"fmt"
 	"go-udemy-web-1/internal/config"
+	"go-udemy-web-1/internal/helpers"
 	"go-udemy-web-1/internal/models"
 	"html/template"
-	"log"
 	"net/http"
 	"path/filepath"
 
@@ -59,14 +59,14 @@ func RenderTemplate(w http.ResponseWriter, r *http.Request, tmpl string, td *mod
 
 	err := t.Execute(buf, td)
 	if err != nil {
-		log.Println(err)
+		helpers.ServerError(w, err)
 		return err
 	}
 
 	// render the template
 	_, err = buf.WriteTo(w)
 	if err != nil {
-		log.Println(err)
+		helpers.ServerError(w, err)
 		return err
 	}
 

internal/render/setup_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/gob"
 	"go-udemy-web-1/internal/config"
 	"go-udemy-web-1/internal/models"
+	"log"
 	"net/http"
 	"os"
 	"testing"
@@ -32,6 +33,12 @@ func TestMain(m *testing.M) {
 
 	testApp.Session = session
 
+	infoLog := log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
+	testApp.InfoLog = infoLog
+
+	errorLog := log.New(os.Stdout, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
+	testApp.ErrorLog = errorLog
+
 	app = &testApp
 
 	os.Exit(m.Run())