Server-side form validation 1

cmd/web/routes.go

@@ -26,6 +26,7 @@ func routes(app *config.AppConfig) http.Handler {
 	mux.Post("/availability", handlers.Repo.PostAvailability)
 	mux.Post("/availability-json", handlers.Repo.AvailabilityJSON)
 	mux.Get("/make-reservation", handlers.Repo.MakeReservation)
+	mux.Post("/make-reservation", handlers.Repo.PostMakeReservation)
 
 	fileServer := http.FileServer(http.Dir("./static/"))
 	mux.Handle("/static/*", http.StripPrefix("/static", fileServer))

internal/forms/errors.go

@@ -0,0 +1,18 @@
+package forms
+
+type errors map[string][]string
+
+// Add adds an error message for a given form field
+func (e errors) Add(field, message string) {
+	e[field] = append(e[field], message)
+}
+
+// Get returns the first error message
+func (e errors) Get(field string) string {
+	es := e[field]
+
+	if len(es) == 0 {
+		return ""
+	}
+	return es[0]
+}

internal/forms/forms.go

@@ -0,0 +1,26 @@
+package forms
+
+import (
+	"net/http"
+	"net/url"
+)
+
+// Form creates a custom form struct, embeds a url.Values object
+type Form struct {
+	url.Values
+	Errors errors
+}
+
+// New initializes a form struct
+func New(data url.Values) *Form {
+	return &Form{
+		data,
+		errors(map[string][]string{}),
+	}
+}
+
+// Has checks if form field is in post and not emtpy
+func (f *Form) Has(field string, r *http.Request) bool {
+	x := r.Form.Get(field)
+	return x != ""
+}

internal/handlers/handlers.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"go-udemy-web-1/internal/config"
+	"go-udemy-web-1/internal/forms"
 	"go-udemy-web-1/internal/models"
 	"go-udemy-web-1/internal/render"
 	"log"
@@ -68,7 +69,13 @@ func (m *Repository) Majors(w http.ResponseWriter, r *http.Request) {
 
 // MakeReservation is the make reservation page handler
 func (m *Repository) MakeReservation(w http.ResponseWriter, r *http.Request) {
-	render.RenderTemplate(w, r, "make-reservation.page.tmpl", &models.TemplateData{})
+	render.RenderTemplate(w, r, "make-reservation.page.tmpl", &models.TemplateData{
+		Form: forms.New(nil),
+	})
+}
+
+// PostMakeReservation is the make reservation page post handler
+func (m *Repository) PostMakeReservation(w http.ResponseWriter, r *http.Request) {
 }
 
 // Availability is the search for availability page handler

internal/models/templatedata.go

@@ -1,5 +1,7 @@
 package models
 
+import "go-udemy-web-1/internal/forms"
+
 // TemplateData holds data sent from handlers to templates
 type TemplateData struct {
 	StringMap map[string]string
@@ -10,4 +12,5 @@ type TemplateData struct {
 	Flash     string
 	Warning   string
 	Error     string
+	Form      *forms.Form
 }

templates/make-reservation.page.tmpl

@@ -5,7 +5,9 @@
         <div class="col">
             <h1 class="text-center mt-3">Make reservation</h1>
 
-            <form method="post" action="" class="needs-validation" novalidate>
+            <!-- <form method="post" action="" class="needs-validation" novalidate> -->
+            <form method="post" action="" class="" novalidate>
+                <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                 <div class="form-group mt-5">
                     <label for="first_name">First name:</label>
                     <input type="text" name="first_name" id="first_name" class="form-control" required