ch11.3

cmd/web/handlers.go

@@ -19,6 +19,13 @@ type snippetCreateForm struct {
 	validator.Validator `form:"-"`
 }
 
+type userSignupForm struct {
+	Name                string `form:"name"`
+	Email               string `form:"email"`
+	Password            string `form:"password"`
+	validator.Validator `form:"-"`
+}
+
 func (app *application) render(w http.ResponseWriter, status int, page string, data *templateData) {
 	ts, ok := app.templateCache[page]
 	if !ok {
@@ -119,7 +126,41 @@ func (app *application) snippetCreatePost(w http.ResponseWriter, r *http.Request
 }
 
 func (app *application) userSignupPost(w http.ResponseWriter, r *http.Request) {
-	fmt.Fprintln(w, "Create a new user...")
+	var form userSignupForm
+	err := app.decodePostForm(r, &form)
+	if err != nil {
+		app.clientError(w, http.StatusBadRequest)
+		return
+	}
+
+	form.CheckField(validator.NotBlank(form.Name), "name", "This field cannot be blank")
+	form.CheckField(validator.NotBlank(form.Email), "email", "This field cannot be blank")
+	form.CheckField(validator.Matches(form.Email, validator.EmailRX), "email", "This field must be a valid email address")
+	form.CheckField(validator.NotBlank(form.Password), "password", "This field cannot be blank")
+	form.CheckField(validator.MinChars(form.Password, 8), "password", "This field must be at least 8 character long")
+
+	if !form.Valid() {
+		data := app.newTemplateData(r)
+		data.Form = form
+		app.render(w, http.StatusUnprocessableEntity, "signup.tmpl", data)
+		return
+	}
+
+	err = app.users.Insert(form.Name, form.Email, form.Password)
+	if err != nil {
+		if errors.Is(err, models.ErrDuplicateEmail) {
+			form.AddFieldError("email", "Email address already in use")
+
+			data := app.newTemplateData(r)
+			data.Form = form
+			app.render(w, http.StatusUnprocessableEntity, "signup.tmpl", data)
+		} else {
+			app.serverError(w, err)
+		}
+		return
+	}
+	app.sessionManager.Put(r.Context(), "flash", "Your singup was successful. Please log in.")
+	http.Redirect(w, r, "/user/login", http.StatusSeeOther)
 }
 
 func (app *application) userLoginPost(w http.ResponseWriter, r *http.Request) {
@@ -131,7 +172,9 @@ func (app *application) userLogoutPost(w http.ResponseWriter, r *http.Request) {
 }
 
 func (app *application) userSignup(w http.ResponseWriter, r *http.Request) {
-	fmt.Fprintln(w, "Display a HTML for signing up a new user...")
+	data := app.newTemplateData(r)
+	data.Form = userSignupForm{}
+	app.render(w, http.StatusOK, "signup.tmpl", data)
 }
 
 func (app *application) userLogin(w http.ResponseWriter, r *http.Request) {

cmd/web/helpers.go

@@ -24,7 +24,7 @@ func (app *application) notFound(w http.ResponseWriter) {
 	app.clientError(w, http.StatusNotFound)
 }
 
-func (app *application) decodePostForm(r *http.Request, snippetForm *snippetCreateForm) error {
+func (app *application) decodePostForm(r *http.Request, snippetForm any) error {
 	err := r.ParseForm()
 	if err != nil {
 		return err

go.mod

@@ -10,4 +10,5 @@ require (
 	github.com/go-sql-driver/mysql v1.9.3 // indirect
 	github.com/julienschmidt/httprouter v1.3.0 // indirect
 	github.com/justinas/alice v1.2.0 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
 )

go.sum

@@ -13,3 +13,5 @@ github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4d
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/justinas/alice v1.2.0 h1:+MHSA/vccVCF4Uq37S42jwlkvI2Xzl7zTPCN5BnZNVo=
 github.com/justinas/alice v1.2.0/go.mod h1:fN5HRH/reO/zrUflLfTN43t3vXvKzvZIENsNEe7i7qA=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=

internal/models/users.go

@@ -2,7 +2,12 @@ package models
 
 import (
 	"database/sql"
+	"errors"
+	"strings"
 	"time"
+
+	"github.com/go-sql-driver/mysql"
+	"golang.org/x/crypto/bcrypt"
 )
 
 type User struct {
@@ -18,6 +23,24 @@ type UserModel struct {
 }
 
 func (m *UserModel) Insert(name, email, password string) error {
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), 12)
+	if err != nil {
+		return err
+	}
+
+	stmt := `INSERT INTO users (name, email, hashed_password, created) 
+	VALUES(?, ?, ?, UTC_TIMESTAMP())`
+
+	_, err = m.DB.Exec(stmt, name, email, string(hashedPassword))
+	if err != nil {
+		var mySQLError *mysql.MySQLError
+		if errors.As(err, &mySQLError) {
+			if mySQLError.Number == 1062 && strings.Contains(mySQLError.Message, "users_uc_email") {
+				return ErrDuplicateEmail
+			}
+		}
+		return err
+	}
 	return nil
 }
 

internal/validator/validator.go

@@ -1,6 +1,7 @@
 package validator
 
 import (
+	"regexp"
 	"strings"
 	"unicode/utf8"
 )
@@ -44,3 +45,13 @@ func PermittedInt(value int, permittedValues ...int) bool {
 	}
 	return false
 }
+
+var EmailRX = regexp.MustCompile("^[a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$")
+
+func MinChars(value string, n int) bool {
+	return utf8.RuneCountInString(value) >= n
+}
+
+func Matches(value string, rx *regexp.Regexp) bool {
+	return rx.MatchString(value)
+}

ui/html/pages/signup.tmpl

@@ -0,0 +1,30 @@
+{{define "title"}}Signup{{end}}
+
+{{define "main"}}
+<form action='/user/signup' method='POST' novalidate>
+    <div>
+        <label>Name:</label>
+        {{with .Form.FieldErrors.name}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='text' name='name' value='{{.Form.Name}}'>
+    </div>
+    <div>
+        <label>Email:</label>
+        {{with .Form.FieldErrors.email}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='email' name='email' value='{{.Form.Email}}'>
+    </div>
+    <div>
+        <label>Password:</label>
+        {{with .Form.FieldErrors.password}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='password' name='password'>
+    </div>
+    <div>
+        <input type='submit' value='Signup'>
+    </div>
+</form>
+{{end}}