add http example

example/http-upload/main.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"github.com/mazrean/formstream"
+	httpform "github.com/mazrean/formstream/http"
+)
+
+const iconDir = "icons"
+
+func main() {
+	err := os.MkdirAll(iconDir, 0755)
+	if err != nil {
+		panic(err)
+	}
+
+	mux := http.NewServeMux()
+
+	mux.HandleFunc("/submit", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+
+		parser, err := httpform.NewParser(r)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		err = parser.Register("icon", func(r io.Reader, header formstream.Header) error {
+			if header.ContentType() != "image/png" {
+				http.Error(w, "content type is not supported", http.StatusBadRequest)
+				return fmt.Errorf("content type is not supported")
+			}
+
+			id, _, _ := parser.Value("id")
+			iconPath := filepath.Join(iconDir, id)
+
+			_, err := os.Stat(iconPath)
+			if err != nil && !os.IsNotExist(err) {
+				http.Error(w, "failed to check file existence", http.StatusInternalServerError)
+				return fmt.Errorf("failed to check file existence: %w", err)
+			}
+
+			if err == nil {
+				http.Error(w, "user already exists", http.StatusConflict)
+				return fmt.Errorf("user already exists")
+			}
+
+			file, err := os.Create(iconPath)
+			if err != nil {
+				http.Error(w, "failed to create file", http.StatusInternalServerError)
+				return fmt.Errorf("failed to create file: %w", err)
+			}
+			defer file.Close()
+
+			_, err = io.Copy(file, r)
+			if err != nil {
+				http.Error(w, "failed to copy", http.StatusInternalServerError)
+				return fmt.Errorf("failed to copy: %w", err)
+			}
+
+			return nil
+		}, formstream.WithRequiredPart("id"))
+		if err != nil {
+			http.Error(w, "failed to register hook", http.StatusInternalServerError)
+			return
+		}
+
+		err = parser.Parse()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		w.WriteHeader(http.StatusCreated)
+	})
+	mux.Handle("/icons/", http.StripPrefix("/icons/", http.FileServer(http.Dir(iconDir))))
+
+	err = http.ListenAndServe(":8080", mux)
+	if err != nil {
+		panic(err)
+	}
+}