Refactor api code: split between packages

internal/myvalidator/myvalidator.go

@@ -0,0 +1,51 @@
+package myvalidator
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+
+	"git.artlef.fr/PersonalLibraryManager/internal/appcontext"
+	"git.artlef.fr/PersonalLibraryManager/internal/i18nresource"
+	"github.com/gin-gonic/gin"
+	"github.com/go-playground/validator/v10"
+)
+
+type apiValidationError struct {
+	Field string `json:"field"`
+	Err   string `json:"error"`
+}
+
+func ManageBindingError(ac appcontext.AppContext, err error) {
+	var ve validator.ValidationErrors
+	if errors.As(err, &ve) {
+		ac.C.JSON(http.StatusBadRequest, getValidationErrors(ac, &ve))
+	} else {
+		ac.C.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+	}
+}
+
+func getValidationErrors(ac appcontext.AppContext, ve *validator.ValidationErrors) []apiValidationError {
+	errors := make([]apiValidationError, len(*ve))
+	for i, fe := range *ve {
+		errors[i] = apiValidationError{
+			Field: fe.Field(),
+			Err:   computeValidationMessage(ac, &fe),
+		}
+	}
+	return errors
+}
+
+func computeValidationMessage(ac appcontext.AppContext, fe *validator.FieldError) string {
+	tag := (*fe).Tag()
+	switch tag {
+	case "required":
+		return i18nresource.GetTranslatedMessage(ac, "ValidationRequired")
+	case "min":
+		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationTooShort"), (*fe).Param())
+	case "max":
+		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationTooLong"), (*fe).Param())
+	default:
+		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationPropertyFail"), tag)
+	}
+}