block.go

package slack

// @NOTE: Blocks are in beta and subject to change.

// More Information: https://api.slack.com/block-kit

// MessageBlockType defines a named string type to define each block type
// as a constant for use within the package.
type MessageBlockType string

const (
	mbtSection MessageBlockType = "section"
	mbtDivider MessageBlockType = "divider"
	mbtImage   MessageBlockType = "image"
	mbtAction  MessageBlockType = "actions"
	mbtContext MessageBlockType = "context"
)

// Block defines an interface all block types should implement
// to ensure consistency between blocks.
type Block interface {
	blockType() MessageBlockType
}

// Blocks is a convenience struct defined to allow dynamic unmarshalling of
// the "blocks" value in Slack's JSON response, which varies depending on block type
type Blocks struct {
	ActionBlocks  []*ActionBlock
	ContextBlocks []*ContextBlock
	DividerBlocks []*DividerBlock
	ImageBlocks   []*ImageBlock
	SectionBlocks []*SectionBlock
}

// BlockAction is the action callback sent when a block is interacted with
type BlockAction struct {
	ActionID string          `json:"action_id"`
	BlockID  string          `json:"block_id"`
	Text     TextBlockObject `json:"text"`
	Value    string          `json:"value"`
	Type     actionType      `json:"type"`
	ActionTs string          `json:"action_ts"`
}

// actionType returns the type of the block action
func (b BlockAction) actionType() actionType {
	return b.Type
}

// NewBlockMessage creates a new Message that contains one or more blocks to be displayed
func NewBlockMessage(blocks ...Block) Message {
	b := Blocks{}
	b.appendToBlocks(blocks)
	return Message{
		Msg: Msg{
			Blocks: b,
		},
	}
}

// AddBlockMessage appends a block to the end of the existing list of blocks
func AddBlockMessage(message Message, newBlk Block) Message {
	message.Msg.Blocks.appendToBlocks([]Block{newBlk})
	return message
}