diff --git a/cmd/web/handlers.go b/cmd/web/handlers.go
index f139c6a..3ed835d 100644
--- a/cmd/web/handlers.go
+++ b/cmd/web/handlers.go
@@ -7,8 +7,22 @@ import (
"strconv"
"snippetbox.tonidefez.net/internal/models"
+ "snippetbox.tonidefez.net/internal/validator"
)
+// Define a snippetCreateForm struct to represent the form data and validation
+// errors for the form fields. Note that all the struct fields are deliberately
+// exported (i.e. start with a capital letter). This is because struct fields
+// must be exported in order to be read by the html/template package when
+// rendering the template.
+type snippetCreateForm struct {
+ Title string
+ Content string
+ Expires int
+ FieldErrors map[string]string
+ validator.Validator
+}
+
func (app *Application) Home(w http.ResponseWriter, r *http.Request) {
w.Header().Add("Server", "Go")
@@ -50,15 +64,60 @@ func (app *Application) SnippetView(w http.ResponseWriter, r *http.Request) {
}
func (app *Application) SnippetCreate(w http.ResponseWriter, r *http.Request) {
- w.Write([]byte("Display a form for creating a new snippet..."))
+ data := app.NewTemplateData(r)
+
+ data.Form = snippetCreateForm{
+ Expires: 365,
+ }
+
+ app.render(w, r, http.StatusOK, "create.tmpl", *data)
}
func (app *Application) SnippetCreatePost(w http.ResponseWriter, r *http.Request) {
- title := "O snail"
- content := "O snail\nClimb Mount Fuji,\nBut slowly, slowly!\n\n– Kobayashi Issa"
- expires := 7
+ err := r.ParseForm()
+ if err != nil {
+ app.clientError(w, http.StatusBadRequest)
+ return
+ }
+
+ // Get the expires value from the form as normal.
+ expires, err := strconv.Atoi(r.PostForm.Get("expires"))
+ if err != nil {
+ app.clientError(w, http.StatusBadRequest)
+ return
+ }
+
+ // Create an instance of the snippetCreateForm struct containing the values
+ // from the form and an empty map for any validation errors.
+ form := snippetCreateForm{
+ Title: r.PostForm.Get("title"),
+ Content: r.PostForm.Get("content"),
+ Expires: expires,
+ }
+
+ // Because the Validator struct is embedded by the snippetCreateForm struct,
+ // we can call CheckField() directly on it to execute our validation checks.
+ // CheckField() will add the provided key and error message to the
+ // FieldErrors map if the check does not evaluate to true. For example, in
+ // the first line here we "check that the form.Title field is not blank". In
+ // the second, we "check that the form.Title field has a maximum character
+ // length of 100" and so on.
+ form.CheckField(validator.NotBlank(form.Title), "title", "This field cannot be blank")
+ form.CheckField(validator.MaxChars(form.Title, 100), "title", "This field cannot be more than 100 characters long")
+ form.CheckField(validator.NotBlank(form.Content), "content", "This field cannot be blank")
+ form.CheckField(validator.PermittedValue(form.Expires, 1, 7, 365), "expires", "This field must equal 1, 7 or 365")
+
+ // Use the Valid() method to see if any of the checks failed. If they did,
+ // then re-render the template passing in the form in the same way as
+ // before.
+ if !form.Valid() {
+ data := app.NewTemplateData(r)
+ data.Form = form
+ app.render(w, r, http.StatusUnprocessableEntity, "create.tmpl", *data)
+ return
+ }
- id, err := app.snippets.Insert(title, content, expires)
+ id, err := app.snippets.Insert(form.Title, form.Content, form.Expires)
if err != nil {
app.serverError(w, r, err)
return
diff --git a/cmd/web/handlers_test.go b/cmd/web/handlers_test.go
index a11e2fd..878ea1c 100644
--- a/cmd/web/handlers_test.go
+++ b/cmd/web/handlers_test.go
@@ -5,6 +5,7 @@ import (
"log/slog"
"net/http"
"net/http/httptest"
+ "net/url"
"strings"
"testing"
@@ -113,10 +114,16 @@ func TestSnippetCreateGet(t *testing.T) {
// simulate dependencies
dummyLogger := slog.New(slog.NewTextHandler(io.Discard, nil))
dummyDB := &models.SnippetModel{DB: nil}
+ templateCache, err := newTemplateCache()
+
+ if err != nil {
+ t.Fatal(err)
+ }
app := &Application{
- logger: dummyLogger,
- snippets: dummyDB,
+ logger: dummyLogger,
+ snippets: dummyDB,
+ templateCache: templateCache,
}
router := app.routes()
@@ -158,3 +165,33 @@ func TestSnippetCreatePost(t *testing.T) {
t.Errorf("expected Location header %q; got %q", expectedLocation, actualLocation)
}
}
+
+func TestSnippetCreatePost_InvalidData(t *testing.T) {
+ templateCache, err := newTemplateCache()
+
+ if err != nil {
+ t.Fatal(err)
+ }
+ app := &Application{
+ templateCache: templateCache,
+ }
+
+ form := url.Values{}
+ form.Add("title", "")
+ form.Add("content", "Some valid content")
+ form.Add("expires", "7")
+
+ req := httptest.NewRequest(http.MethodPost, "/snippet/create", strings.NewReader(form.Encode()))
+ req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+ rr := httptest.NewRecorder()
+
+ app.SnippetCreatePost(rr, req)
+
+ res := rr.Result()
+ defer res.Body.Close()
+
+ if res.StatusCode != http.StatusUnprocessableEntity {
+ t.Errorf("expected status 422 OK; got %d", res.StatusCode)
+ }
+}
diff --git a/cmd/web/helper.go b/cmd/web/helper.go
index 287b241..307c040 100644
--- a/cmd/web/helper.go
+++ b/cmd/web/helper.go
@@ -5,6 +5,8 @@ import (
"fmt"
"net/http"
"runtime/debug"
+
+ "snippetbox.tonidefez.net/internal/models"
)
// The serverError helper writes a log entry at Error level (including the request
@@ -49,3 +51,10 @@ func (app *Application) render(w http.ResponseWriter, r *http.Request, status in
w.WriteHeader(status)
buf.WriteTo(w)
}
+
+func (app *Application) NewTemplateData(r *http.Request) *templateData {
+ return &templateData{
+ Snippet: models.Snippet{},
+ Snippets: []models.Snippet{},
+ }
+}
diff --git a/cmd/web/templates.go b/cmd/web/templates.go
index 08336ba..7cc669c 100644
--- a/cmd/web/templates.go
+++ b/cmd/web/templates.go
@@ -13,8 +13,10 @@ import (
// At the moment it only contains one field, but we'll add more
// to it as the build progresses.
type templateData struct {
- Snippet models.Snippet
- Snippets []models.Snippet
+ CurrentYear int
+ Snippet models.Snippet
+ Snippets []models.Snippet
+ Form any
}
func newTemplateCache() (map[string]*template.Template, error) {
diff --git a/internal/validator/validator.go b/internal/validator/validator.go
new file mode 100644
index 0000000..696dfa7
--- /dev/null
+++ b/internal/validator/validator.go
@@ -0,0 +1,56 @@
+package validator
+
+import (
+ "slices"
+ "strings"
+ "unicode/utf8"
+)
+
+// Define a new Validator struct which contains a map of validation error messages
+// for our form fields.
+type Validator struct {
+ FieldErrors map[string]string
+}
+
+// Valid() returns true if the FieldErrors map doesn't contain any entries.
+func (v *Validator) Valid() bool {
+ return len(v.FieldErrors) == 0
+}
+
+// AddFieldError() adds an error message to the FieldErrors map (so long as no
+// entry already exists for the given key).
+func (v *Validator) AddFieldError(key, message string) {
+ // Note: We need to initialize the map first, if it isn't already
+ // initialized.
+ if v.FieldErrors == nil {
+ v.FieldErrors = make(map[string]string)
+ }
+
+ if _, exists := v.FieldErrors[key]; !exists {
+ v.FieldErrors[key] = message
+ }
+}
+
+// CheckField() adds an error message to the FieldErrors map only if a
+// validation check is not 'ok'.
+func (v *Validator) CheckField(ok bool, key, message string) {
+ if !ok {
+ v.AddFieldError(key, message)
+ }
+}
+
+// NotBlank() returns true if a value is not an empty string.
+func NotBlank(value string) bool {
+ return strings.TrimSpace(value) != ""
+}
+
+// MaxChars() returns true if a value contains no more than n characters.
+func MaxChars(value string, n int) bool {
+ return utf8.RuneCountInString(value) <= n
+}
+
+// PermittedValue() returns true if a value is in a list of specific permitted
+// values.
+func PermittedValue[T comparable](value T, permittedValues ...T) bool {
+ return slices.Contains(permittedValues, value)
+}
diff --git a/ui/html/pages/create.tmpl b/ui/html/pages/create.tmpl
new file mode 100644
index 0000000..9ec668f
--- /dev/null
+++ b/ui/html/pages/create.tmpl
@@ -0,0 +1,43 @@
+{{define "title"}}Create a New Snippet{{end}}
+
+{{define "main"}}
+
+{{end}}
\ No newline at end of file
diff --git a/ui/html/partials/nav.tmpl b/ui/html/partials/nav.tmpl
index e5222bf..571e8d3 100644
--- a/ui/html/partials/nav.tmpl
+++ b/ui/html/partials/nav.tmpl
@@ -1,5 +1,7 @@
{{define "nav"}}
{{end}}
\ No newline at end of file