add datetimepicker component

block.go

@@ -50,6 +50,7 @@ type BlockAction struct {
 	SelectedConversations []string            `json:"selected_conversations"`
 	SelectedDate          string              `json:"selected_date"`
 	SelectedTime          string              `json:"selected_time"`
+	SelectedDateTime      int64               `json:"selected_date_time"`
 	InitialOption         OptionBlockObject   `json:"initial_option"`
 	InitialUser           string              `json:"initial_user"`
 	InitialChannel        string              `json:"initial_channel"`

block_conv.go

@@ -110,6 +110,8 @@ func (b *InputBlock) UnmarshalJSON(data []byte) error {
 		e = &DatePickerBlockElement{}
 	case "timepicker":
 		e = &TimePickerBlockElement{}
+	case "datetimepicker":
+		e = &DateTimePickerBlockElement{}
 	case "plain_text_input":
 		e = &PlainTextInputBlockElement{}
 	case "email_text_input":
@@ -190,6 +192,8 @@ func (b *BlockElements) UnmarshalJSON(data []byte) error {
 			blockElement = &DatePickerBlockElement{}
 		case "timepicker":
 			blockElement = &TimePickerBlockElement{}
+		case "datetimepicker":
+			blockElement = &DateTimePickerBlockElement{}
 		case "plain_text_input":
 			blockElement = &PlainTextInputBlockElement{}
 		case "email_text_input":
@@ -233,6 +237,7 @@ func (a *Accessory) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON implements the Unmarshaller interface for Accessory, so that any JSON
 // unmarshalling is delegated and proper type determination can be made before unmarshal
+// Note: datetimepicker is not supported in Accessory
 func (a *Accessory) UnmarshalJSON(data []byte) error {
 	var r json.RawMessage
 

block_element.go

@@ -9,6 +9,7 @@ const (
 	METOverflow       MessageElementType = "overflow"
 	METDatepicker     MessageElementType = "datepicker"
 	METTimepicker     MessageElementType = "timepicker"
+	METDatetimepicker MessageElementType = "datetimepicker"
 	METPlainTextInput MessageElementType = "plain_text_input"
 	METRadioButtons   MessageElementType = "radio_buttons"
 	METEmailTextInput MessageElementType = "email_text_input"
@@ -392,6 +393,29 @@ func NewTimePickerBlockElement(actionID string) *TimePickerBlockElement {
 	}
 }
 
+// DateTimePickerBlockElement defines an element that allows the selection of both
+// a date and a time of day formatted as a UNIX timestamp.
+// More Information: https://api.slack.com/reference/messaging/block-elements#datetimepicker
+type DateTimePickerBlockElement struct {
+	Type            MessageElementType       `json:"type"`
+	ActionID        string                   `json:"action_id,omitempty"`
+	InitialDateTime int64                    `json:"initial_date_time,omitempty"`
+	Confirm         *ConfirmationBlockObject `json:"confirm,omitempty"`
+}
+
+// ElementType returns the type of the Element
+func (s DateTimePickerBlockElement) ElementType() MessageElementType {
+	return s.Type
+}
+
+// NewDatePickerBlockElement returns an instance of a datetime picker element
+func NewDateTimePickerBlockElement(actionID string) *DateTimePickerBlockElement {
+	return &DateTimePickerBlockElement{
+		Type:     METDatetimepicker,
+		ActionID: actionID,
+	}
+}
+
 // EmailTextInputBlockElement creates a field where a user can enter email
 // data.
 // email-text-input elements are currently only available in modals.

block_element_test.go

@@ -133,6 +133,12 @@ func TestNewTimePickerBlockElement(t *testing.T) {
 	assert.Equal(t, timepickerElement.ActionID, "test")
 }
 
+func TestNewDateTimePickerBlockElement(t *testing.T) {
+	datetimepickerElement := NewDateTimePickerBlockElement("test")
+	assert.Equal(t, string(datetimepickerElement.Type), "datetimepicker")
+	assert.Equal(t, datetimepickerElement.ActionID, "test")
+}
+
 func TestNewPlainTextInputBlockElement(t *testing.T) {
 
 	plainTextInputElement := NewPlainTextInputBlockElement(nil, "test")