Add block element type FileInput

block.go

@@ -39,6 +39,7 @@ type BlockAction struct {
 	Type                  ActionType          `json:"type"`
 	Text                  TextBlockObject     `json:"text"`
 	Value                 string              `json:"value"`
+	Files                 []File              `json:"files"`
 	ActionTs              string              `json:"action_ts"`
 	SelectedOption        OptionBlockObject   `json:"selected_option"`
 	SelectedOptions       []OptionBlockObject `json:"selected_options"`

block_conv.go

@@ -130,6 +130,8 @@ func (b *InputBlock) UnmarshalJSON(data []byte) error {
 		e = &RadioButtonsBlockElement{}
 	case "number_input":
 		e = &NumberInputBlockElement{}
+	case "file_input":
+		e = &FileInputBlockElement{}
 	default:
 		return errors.New("unsupported block element type")
 	}

block_element.go

@@ -15,6 +15,7 @@ const (
 	METEmailTextInput MessageElementType = "email_text_input"
 	METURLTextInput   MessageElementType = "url_text_input"
 	METNumber         MessageElementType = "number_input"
+	METFileInput      MessageElementType = "file_input"
 
 	MixedElementImage MixedElementType = "mixed_image"
 	MixedElementText  MixedElementType = "mixed_text"
@@ -591,3 +592,40 @@ func NewNumberInputBlockElement(placeholder *TextBlockObject, actionID string, i
 		IsDecimalAllowed: isDecimalAllowed,
 	}
 }
+
+// FileInputBlockElement creates a field where a user can upload a file.
+//
+// File input elements are currently only available in modals.
+//
+// More Information: https://api.slack.com/reference/block-kit/block-elements#file_input
+type FileInputBlockElement struct {
+	Type      MessageElementType `json:"type"`
+	ActionID  string             `json:"action_id,omitempty"`
+	FileTypes []string           `json:"filetypes,omitempty"`
+	MaxFiles  int                `json:"max_files,omitempty"`
+}
+
+// ElementType returns the type of the Element
+func (s FileInputBlockElement) ElementType() MessageElementType {
+	return s.Type
+}
+
+// NewFileInputBlockElement returns an instance of a file input element
+func NewFileInputBlockElement(actionID string) *FileInputBlockElement {
+	return &FileInputBlockElement{
+		Type:     METFileInput,
+		ActionID: actionID,
+	}
+}
+
+// WithFileTypes sets the file types that can be uploaded
+func (s *FileInputBlockElement) WithFileTypes(fileTypes ...string) *FileInputBlockElement {
+	s.FileTypes = fileTypes
+	return s
+}
+
+// WithMaxFiles sets the maximum number of files that can be uploaded
+func (s *FileInputBlockElement) WithMaxFiles(maxFiles int) *FileInputBlockElement {
+	s.MaxFiles = maxFiles
+	return s
+}

block_element_test.go

@@ -215,3 +215,19 @@ func TestNewNumberInputBlockElement(t *testing.T) {
 	assert.Equal(t, numberInputElement.IsDecimalAllowed, true)
 
 }
+
+func TestNewFileInputBlockElement(t *testing.T) {
+
+	fileInputElement := NewFileInputBlockElement("test")
+
+	assert.Equal(t, string(fileInputElement.Type), "file_input")
+	assert.Equal(t, fileInputElement.ActionID, "test")
+
+	fileInputElement.WithFileTypes("jpg", "png")
+	assert.Equal(t, len(fileInputElement.FileTypes), 2)
+	assert.Contains(t, fileInputElement.FileTypes, "jpg")
+	assert.Contains(t, fileInputElement.FileTypes, "png")
+
+	fileInputElement.WithMaxFiles(10)
+	assert.Equal(t, fileInputElement.MaxFiles, 10)
+}