feat: initial commit

internal/http/form/field.go

@@ -0,0 +1,85 @@
+package form
+
+import (
+	"github.com/pkg/errors"
+)
+
+type Attrs map[string]any
+
+type FieldUnmarshaller interface {
+	Unmarshal(v string) error
+}
+
+type ValidationFunc func(f *Field) error
+
+type Field struct {
+	name       string
+	attrs      map[string]any
+	validators []ValidationFunc
+}
+
+func (f *Field) Name() string {
+	return f.name
+}
+
+func (f *Field) Get(key string) (value any, exists bool) {
+	value, exists = f.attrs[key]
+	return
+}
+
+func (f *Field) Set(key string, value any) {
+	f.attrs[key] = value
+}
+
+func (f *Field) Del(key string) {
+	delete(f.attrs, key)
+}
+
+func (f *Field) Attrs() map[string]any {
+	return f.attrs
+}
+
+func (f *Field) Validate() error {
+	for _, fn := range f.validators {
+		if err := fn(f); err != nil {
+			return errors.WithStack(err)
+		}
+	}
+	return nil
+}
+
+func NewField(name string, attrs Attrs, validators ...ValidationFunc) *Field {
+	return &Field{
+		name:       name,
+		attrs:      attrs,
+		validators: validators,
+	}
+}
+
+func FormFieldAttr[T any](f *Form, name string, attr string) (T, error) {
+	field := f.Field(name)
+	if field == nil {
+		return *new(T), errors.WithStack(ErrFieldNotFound)
+	}
+
+	value, err := FieldAttr[T](field, attr)
+	if err != nil {
+		return *new(T), errors.WithStack(err)
+	}
+
+	return value, nil
+}
+
+func FieldAttr[T any](f *Field, name string) (T, error) {
+	raw, ok := f.Get(name)
+	if !ok {
+		return *new(T), errors.WithStack(ErrMissingValue)
+	}
+
+	value, ok := raw.(T)
+	if !ok {
+		return *new(T), errors.WithStack(ErrUnexpectedValue)
+	}
+
+	return value, nil
+}