Auto populated select menus (#1269)

* feat(components): auto-populated selects

* Add component types for user, channel, role and mentionable selects
* Add MenuType field to SelectMenu for customization of select type
* Add basic example for auto-populated selects

* feat: implement SelectMenuType to restrict component types

Implement SelectMenuType to restrict component types that can be used
in MenuType field of SelectMenu structure.

* fix(SelectMenu): default type

Default to SelectMenuComponent type when MenuType is not specified.

* feat(examples/components): add ephemeral

Add ephemeral flag into response to match other component examples.

* feat(examples): option response and refactoring

* Add a response to the selected option.
* Refactor the command to match others.
* Remove showcase of multiple menu types.

components.go

@@ -14,6 +14,10 @@ const (
 	ButtonComponent                ComponentType = 2
 	SelectMenuComponent            ComponentType = 3
 	TextInputComponent             ComponentType = 4
+	UserSelectMenuComponent        ComponentType = 5
+	RoleSelectMenuComponent        ComponentType = 6
+	MentionableSelectMenuComponent ComponentType = 7
+	ChannelSelectMenuComponent     ComponentType = 8
 )
 
 // MessageComponent is a base interface for all message components.
@@ -41,7 +45,8 @@ func (umc *unmarshalableMessageComponent) UnmarshalJSON(src []byte) error {
 		umc.MessageComponent = &ActionsRow{}
 	case ButtonComponent:
 		umc.MessageComponent = &Button{}
-	case SelectMenuComponent:
+	case SelectMenuComponent, ChannelSelectMenuComponent, UserSelectMenuComponent,
+		RoleSelectMenuComponent, MentionableSelectMenuComponent:
 		umc.MessageComponent = &SelectMenu{}
 	case TextInputComponent:
 		umc.MessageComponent = &TextInput{}
@@ -169,8 +174,23 @@ type SelectMenuOption struct {
 	Default bool `json:"default"`
 }
 
+// SelectMenuType represents select menu type.
+type SelectMenuType ComponentType
+
+// SelectMenu types.
+const (
+	StringSelectMenu      = SelectMenuType(SelectMenuComponent)
+	UserSelectMenu        = SelectMenuType(UserSelectMenuComponent)
+	RoleSelectMenu        = SelectMenuType(RoleSelectMenuComponent)
+	MentionableSelectMenu = SelectMenuType(MentionableSelectMenuComponent)
+	ChannelSelectMenu     = SelectMenuType(ChannelSelectMenuComponent)
+)
+
 // SelectMenu represents select menu component.
 type SelectMenu struct {
+	// Type of the select menu.
+	MenuType SelectMenuType `json:"type,omitempty"`
+	// CustomID is a developer-defined identifier for the select menu.
 	CustomID string `json:"custom_id,omitempty"`
 	// The text which will be shown in the menu if there's no default options or all options was deselected and component was closed.
 	Placeholder string `json:"placeholder"`
@@ -179,25 +199,31 @@ type SelectMenu struct {
 	// This value determines the maximal amount of selected items in the menu.
 	// If MaxValues or MinValues are greater than one then the user can select multiple items in the component.
 	MaxValues int                `json:"max_values,omitempty"`
-	Options   []SelectMenuOption `json:"options"`
+	Options   []SelectMenuOption `json:"options,omitempty"`
 	Disabled  bool               `json:"disabled"`
+
+	// NOTE: Can only be used in SelectMenu with Channel menu type.
+	ChannelTypes []ChannelType `json:"channel_types,omitempty"`
 }
 
 // Type is a method to get the type of a component.
-func (SelectMenu) Type() ComponentType {
+func (s SelectMenu) Type() ComponentType {
+	if s.MenuType != 0 {
+		return ComponentType(s.MenuType)
+	}
 	return SelectMenuComponent
 }
 
 // MarshalJSON is a method for marshaling SelectMenu to a JSON object.
-func (m SelectMenu) MarshalJSON() ([]byte, error) {
+func (s SelectMenu) MarshalJSON() ([]byte, error) {
 	type selectMenu SelectMenu
 
 	return Marshal(struct {
 		selectMenu
 		Type ComponentType `json:"type"`
 	}{
-		selectMenu: selectMenu(m),
+		selectMenu: selectMenu(s),
-		Type:       m.Type(),
+		Type:       s.Type(),
 	})
 }
 

examples/components/main.go

@@ -165,7 +165,19 @@ var (
 			}
 			time.Sleep(time.Second) // Doing that so user won't see instant response.
 			_, err = s.FollowupMessageCreate(i.Interaction, true, &discordgo.WebhookParams{
-				Content: "Now you know everything about select component. If you want to know more or ask a question - feel free to.",
+				Content: "But wait, there is more! You can also auto populate the select menu. Try executing `/selects auto-populated`.",
+				Flags:   discordgo.MessageFlagsEphemeral,
+			})
+			if err != nil {
+				panic(err)
+			}
+		},
+		"channel_select": func(s *discordgo.Session, i *discordgo.InteractionCreate) {
+			err := s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+				Type: discordgo.InteractionResponseChannelMessageWithSource,
+				Data: &discordgo.InteractionResponseData{
+					Content: "This is it. You've reached your destination. Your choice was <#" + i.MessageComponentData().Values[0] + ">\n" +
+						"If you want to know more, check out the links below",
 					Components: []discordgo.MessageComponent{
 						discordgo.ActionsRow{
 							Components: []discordgo.MessageComponent{
@@ -196,7 +208,9 @@ var (
 							},
 						},
 					},
+
 					Flags: discordgo.MessageFlagsEphemeral,
+				},
 			})
 			if err != nil {
 				panic(err)
@@ -318,7 +332,7 @@ var (
 				response = &discordgo.InteractionResponse{
 					Type: discordgo.InteractionResponseChannelMessageWithSource,
 					Data: &discordgo.InteractionResponseData{
-						Content: "The tastiest things are left for the end. Let's see how the multi-item select menu works: " +
+						Content: "Now let's see how the multi-item select menu works: " +
 							"try generating your own stackoverflow search link",
 						Flags: discordgo.MessageFlagsEphemeral,
 						Components: []discordgo.MessageComponent{
@@ -381,7 +395,27 @@ var (
 						},
 					},
 				}
-
+			case "auto-populated":
+				response = &discordgo.InteractionResponse{
+					Type: discordgo.InteractionResponseChannelMessageWithSource,
+					Data: &discordgo.InteractionResponseData{
+						Content: "The tastiest things are left for the end. Meet auto populated select menus.\n" +
+							"By setting `MenuType` on the select menu you can tell Discord to automatically populate the menu with entities of your choice: roles, members, channels. Try one below.",
+						Flags: discordgo.MessageFlagsEphemeral,
+						Components: []discordgo.MessageComponent{
+							discordgo.ActionsRow{
+								Components: []discordgo.MessageComponent{
+									discordgo.SelectMenu{
+										MenuType:     discordgo.ChannelSelectMenu,
+										CustomID:     "channel_select",
+										Placeholder:  "Pick your favorite channel!",
+										ChannelTypes: []discordgo.ChannelType{discordgo.ChannelTypeGuildText},
+									},
+								},
+							},
+						},
+					},
+				}
 			}
 			err := s.InteractionRespond(i.Interaction, response)
 			if err != nil {
@@ -430,6 +464,11 @@ func main() {
 				Name:        "single",
 				Description: "Single-item select menu",
 			},
+			{
+				Type:        discordgo.ApplicationCommandOptionSubCommand,
+				Name:        "auto-populated",
+				Description: "Automatically populated select menu, which lets you pick a member, channel or role",
+			},
 		},
 		Description: "Lo and behold: dropdowns are coming",
 	})