Changed interfaces to be private, updated related code and tests. Imp…

…lemented getType for each interface to properly identify blocks, elements, and objects

block.go

@@ -4,39 +4,48 @@ package slack
 
 // More Information: https://api.slack.com/block-kit
 
-var (
-	// validBlockList contains a list of
-	validBlockList = []string{
-		"section",
-		"divider",
-		"image",
-		"actions",
-		"context",
-	}
+// MessageBlockType defines a named string type to define each block type
+// as a constant for use within the package.
+type MessageBlockType string
+type MessageElementType string
+type MessageObjectType string
+
+const (
+	mbtSection MessageBlockType = "section"
+	mbtDivider MessageBlockType = "divider"
+	mbtImage   MessageBlockType = "image"
+	mbtAction  MessageBlockType = "actions"
+	mbtContext MessageBlockType = "context"
+
+	metImage      MessageElementType = "image"
+	metButton     MessageElementType = "button"
+	metOverflow   MessageElementType = "overflow"
+	metDatepicker MessageElementType = "datepicker"
+	metSelect     MessageElementType = "static_select"
+
+	motImage        MessageObjectType = "image"
+	motConfirmation MessageObjectType = "confirmation"
+	motOption       MessageObjectType = "option"
+	motOptionGroup  MessageObjectType = "option_group"
 )
 
-// Block defines an interface all block types should implement
+// block defines an interface all block types should implement
 // to ensure consistency between blocks.
-type Block interface {
-	ValidateBlock() bool
+type block interface {
+	blockType() MessageBlockType
 }
 
 // NewBlockMessage creates a new Message that contains one or more blocks to be displayed
-func NewBlockMessage(blocks ...Block) Message {
+func NewBlockMessage(blocks ...block) Message {
 	return Message{
 		Msg: Msg{
 			Blocks: blocks,
 		},
 	}
 }
 
-// isStringInSlice is a helper function used in validating the block structs to
-// verify a valid type has been used.
-func isStringInSlice(a []string, x string) bool {
-	for _, n := range a {
-		if x == n {
-			return true
-		}
-	}
-	return false
+// AddBlockMessage appends a block to the end of the existing list of blocks
+func AddBlockMessage(message Message, newBlk block) Message {
+	message.Msg.Blocks = append(message.Msg.Blocks, newBlk)
+	return message
 }

block_action.go

@@ -1,26 +1,23 @@
 package slack
 
-import "strings"
-
 // ActionBlock defines data that is used to hold interactive elements.
 //
 // More Information: https://api.slack.com/reference/messaging/blocks#actions
 type ActionBlock struct {
-	Type     string         `json:"type"`
-	BlockID  string         `json:"block_id,omitempty"`
-	Elements []BlockElement `json:"elements"`
+	Type     MessageBlockType `json:"type"`
+	BlockID  string           `json:"block_id,omitempty"`
+	Elements []blockElement   `json:"elements"`
 }
 
-// ValidateBlock ensures that the type set to the block is found in the list of
-// valid slack block.
-func (s *ActionBlock) ValidateBlock() bool {
-	return isStringInSlice(validBlockList, strings.ToLower(s.Type))
+// blockType returns the type of the block
+func (s ActionBlock) blockType() MessageBlockType {
+	return s.Type
 }
 
 // NewActionBlock returns a new instance of an Action Block
-func NewActionBlock(blockID string, elements ...BlockElement) *ActionBlock {
+func NewActionBlock(blockID string, elements ...blockElement) *ActionBlock {
 	return &ActionBlock{
-		Type:     "actions",
+		Type:     mbtAction,
 		BlockID:  blockID,
 		Elements: elements,
 	}

block_action_test.go

@@ -12,7 +12,7 @@ func TestNewActionBlock(t *testing.T) {
 	approveBtn := NewButtonBlockElement("", "click_me_123", approveBtnTxt)
 
 	actionBlock := NewActionBlock("test", approveBtn)
-	assert.Equal(t, actionBlock.Type, "actions")
+	assert.Equal(t, string(actionBlock.Type), "actions")
 	assert.Equal(t, actionBlock.BlockID, "test")
 	assert.Equal(t, len(actionBlock.Elements), 1)
 

block_context.go

@@ -1,27 +1,24 @@
 package slack
 
-import "strings"
-
 // ContextBlock defines data that is used to display message context, which can
 // include both images and text.
 //
 // More Information: https://api.slack.com/reference/messaging/blocks#actions
 type ContextBlock struct {
-	Type     string        `json:"type"`
-	BlockID  string        `json:"block_id,omitempty"`
-	Elements []BlockObject `json:"elements"`
+	Type     MessageBlockType `json:"type"`
+	BlockID  string           `json:"block_id,omitempty"`
+	Elements []blockObject    `json:"elements"`
 }
 
-// ValidateBlock ensures that the type set to the block is found in the list of
-// valid slack block.
-func (s *ContextBlock) ValidateBlock() bool {
-	return isStringInSlice(validBlockList, strings.ToLower(s.Type))
+// blockType returns the type of the block
+func (s ContextBlock) blockType() MessageBlockType {
+	return s.Type
 }
 
 // NewContextBlock returns a newinstance of a context block
-func NewContextBlock(blockID string, elements ...BlockObject) *ContextBlock {
+func NewContextBlock(blockID string, elements ...blockObject) *ContextBlock {
 	return &ContextBlock{
-		Type:     "context",
+		Type:     mbtContext,
 		BlockID:  blockID,
 		Elements: elements,
 	}

block_context_test.go

@@ -12,7 +12,7 @@ func TestNewContextBlock(t *testing.T) {
 	textExample := NewTextBlockObject("plain_text", "Location: Central Business District", true, false)
 
 	actionBlock := NewContextBlock("test", locationPinImage, textExample)
-	assert.Equal(t, actionBlock.Type, "context")
+	assert.Equal(t, string(actionBlock.Type), "context")
 	assert.Equal(t, actionBlock.BlockID, "test")
 	assert.Equal(t, len(actionBlock.Elements), 2)
 

block_divider.go

@@ -1,27 +1,23 @@
 package slack
 
-import "strings"
-
 // DividerBlock for displaying a divider line between blocks (similar to <hr> tag in html)
 //
 // More Information: https://api.slack.com/reference/messaging/blocks#divider
 type DividerBlock struct {
-	Type    string `json:"type"`
-	BlockID string `json:"block_id,omitempty"`
+	Type    MessageBlockType `json:"type"`
+	BlockID string           `json:"block_id,omitempty"`
 }
 
-// ValidateBlock ensures that the type set to the block is found in the list of
-// valid slack block.
-func (s *DividerBlock) ValidateBlock() bool {
-	return isStringInSlice(validBlockList, strings.ToLower(s.Type))
-
+// blockType returns the type of the block
+func (s DividerBlock) blockType() MessageBlockType {
+	return s.Type
 }
 
 // NewDividerBlock returns a new instance of a divider block
 func NewDividerBlock() *DividerBlock {
 
 	return &DividerBlock{
-		Type: "divider",
+		Type: mbtDivider,
 	}
 
 }

block_divider_test.go

@@ -9,6 +9,6 @@ import (
 func TestNewDividerBlock(t *testing.T) {
 
 	dividerBlock := NewDividerBlock()
-	assert.Equal(t, dividerBlock.Type, "divider")
+	assert.Equal(t, string(dividerBlock.Type), "divider")
 
 }

block_element.go

@@ -2,10 +2,10 @@ package slack
 
 // https://api.slack.com/reference/messaging/block-elements
 
-// BlockElement defines an interface that all block element types should
+// blockElement defines an interface that all block element types should
 // implement.
-type BlockElement interface {
-	ValidateElement() bool
+type blockElement interface {
+	blockType() MessageElementType
 }
 
 // ImageBlockElement An element to insert an image - this element can be used
@@ -14,20 +14,20 @@ type BlockElement interface {
 //
 // More Information: https://api.slack.com/reference/messaging/block-elements#image
 type ImageBlockElement struct {
-	Type     string `json:"type"`
-	ImageURL string `json:"image_url"`
-	AltText  string `json:"alt_text"`
+	Type     MessageElementType `json:"type"`
+	ImageURL string             `json:"image_url"`
+	AltText  string             `json:"alt_text"`
 }
 
-// ValidateElement performs validation checks to ensure the element is valid
-func (s ImageBlockElement) ValidateElement() bool {
-	return true
+// validateType enforces block objects for block parameters
+func (s ImageBlockElement) blockType() MessageElementType {
+	return s.Type
 }
 
 // NewImageBlockElement returns a new instance of an image block element
 func NewImageBlockElement(imageURL, altText string) *ImageBlockElement {
 	return &ImageBlockElement{
-		Type:     "image",
+		Type:     metImage,
 		ImageURL: imageURL,
 		AltText:  altText,
 	}
@@ -39,23 +39,23 @@ func NewImageBlockElement(imageURL, altText string) *ImageBlockElement {
 //
 // More Information: https://api.slack.com/reference/messaging/block-elements#button
 type ButtonBlockElement struct {
-	Type     string                   `json:"type,omitempty"`
+	Type     MessageElementType       `json:"type,omitempty"`
 	Text     *TextBlockObject         `json:"text"`
 	ActionID string                   `json:"action_id,omitempty"`
 	URL      string                   `json:"url,omitempty"`
 	Value    string                   `json:"value,omitempty"`
 	Confirm  *ConfirmationBlockObject `json:"confirm,omitempty"`
 }
 
-// ValidateElement performs validation checks to ensure the element is valid
-func (s ButtonBlockElement) ValidateElement() bool {
-	return true
+// validateType enforces block objects for block parameters
+func (s ButtonBlockElement) blockType() MessageElementType {
+	return s.Type
 }
 
 // NewButtonBlockElement returns an instance of a new button element to be used within a block
 func NewButtonBlockElement(actionID, value string, text *TextBlockObject) *ButtonBlockElement {
 	return &ButtonBlockElement{
-		Type:     "button",
+		Type:     metButton,
 		ActionID: actionID,
 		Text:     text,
 		Value:    value,
@@ -76,9 +76,9 @@ type SelectBlockElement struct {
 	Confirm       *ConfirmationBlockObject  `json:"confirm,omitempty"`
 }
 
-// ValidateElement performs validation checks to ensure the element is valid
-func (s SelectBlockElement) ValidateElement() bool {
-	return true
+// validateType enforces block objects for block parameters
+func (s SelectBlockElement) blockType() MessageElementType {
+	return MessageElementType(s.Type)
 }
 
 // NewOptionsSelectBlockElement returns a new instance of SelectBlockElement for use with
@@ -115,21 +115,21 @@ func NewOptionsGroupSelectBlockElement(
 //
 // More Information: https://api.slack.com/reference/messaging/block-elements#overflow
 type OverflowBlockElement struct {
-	Type     string                   `json:"type"`
+	Type     MessageElementType       `json:"type"`
 	ActionID string                   `json:"action_id,omitempty"`
 	Options  []*OptionBlockObject     `json:"options"`
 	Confirm  *ConfirmationBlockObject `json:"confirm,omitempty"`
 }
 
-// ValidateElement performs validation checks to ensure the element is valid
-func (s OverflowBlockElement) ValidateElement() bool {
-	return true
+// validateType enforces block objects for block parameters
+func (s OverflowBlockElement) blockType() MessageElementType {
+	return s.Type
 }
 
 // NewOverflowBlockElement returns an instance of a new Overflow Block Element
 func NewOverflowBlockElement(actionID string, options ...*OptionBlockObject) *OverflowBlockElement {
 	return &OverflowBlockElement{
-		Type:     "overflow",
+		Type:     metOverflow,
 		ActionID: actionID,
 		Options:  options,
 	}
@@ -141,22 +141,22 @@ func NewOverflowBlockElement(actionID string, options ...*OptionBlockObject) *Ov
 //
 // More Information: https://api.slack.com/reference/messaging/block-elements#datepicker
 type DatePickerBlockElement struct {
-	Type        string                   `json:"type"`
+	Type        MessageElementType       `json:"type"`
 	ActionID    string                   `json:"action_id"`
 	Placeholder *TextBlockObject         `json:"placeholder,omitempty"`
 	InitialDate string                   `json:"initial_date,omitempty"`
 	Confirm     *ConfirmationBlockObject `json:"confirm,omitempty"`
 }
 
-// ValidateElement performs validation checks to ensure the element is valid
-func (s DatePickerBlockElement) ValidateElement() bool {
-	return true
+// validateType enforces block objects for block parameters
+func (s DatePickerBlockElement) blockType() MessageElementType {
+	return s.Type
 }
 
 // NewDatePickerBlockElement returns an instance of a date picker element
 func NewDatePickerBlockElement(actionID string) *DatePickerBlockElement {
 	return &DatePickerBlockElement{
-		Type:     "datepicker",
+		Type:     metDatepicker,
 		ActionID: actionID,
 	}
 }

block_element_test.go

@@ -10,7 +10,7 @@ func TestNewImageBlockElement(t *testing.T) {
 
 	imageElement := NewImageBlockObject("https://api.slack.com/img/blocks/bkb_template_images/tripAgentLocationMarker.png", "Location Pin Icon")
 
-	assert.Equal(t, imageElement.Type, "image")
+	assert.Equal(t, string(imageElement.Type), "image")
 	assert.Contains(t, imageElement.ImageURL, "tripAgentLocationMarker")
 	assert.Equal(t, imageElement.AltText, "Location Pin Icon")
 
@@ -21,7 +21,7 @@ func TestNewButtonBlockElement(t *testing.T) {
 	btnTxt := NewTextBlockObject("plain_text", "Next 2 Results", false, false)
 	btnElement := NewButtonBlockElement("test", "click_me_123", btnTxt)
 
-	assert.Equal(t, btnElement.Type, "button")
+	assert.Equal(t, string(btnElement.Type), "button")
 	assert.Equal(t, btnElement.ActionID, "test")
 	assert.Equal(t, btnElement.Value, "click_me_123")
 	assert.Equal(t, btnElement.Text.Text, "Next 2 Results")
@@ -49,7 +49,7 @@ func TestNewOptionsGroupSelectBlockElement(t *testing.T) {
 
 	optGroup := NewOptionsGroupSelectBlockElement("static_select", nil, "test", testGroupOption)
 
-	assert.Equal(t, optGroup.Type, "static_select")
+	assert.Equal(t, string(optGroup.Type), "static_select")
 	assert.Equal(t, optGroup.ActionID, "test")
 	assert.Equal(t, len(optGroup.OptionGroups), 1)
 
@@ -70,7 +70,7 @@ func TestNewOverflowBlockElement(t *testing.T) {
 	// Build overflow section
 	overflowElement := NewOverflowBlockElement("test", overflowOptionOne, overflowOptionTwo, overflowOptionThree)
 
-	assert.Equal(t, overflowElement.Type, "overflow")
+	assert.Equal(t, string(overflowElement.Type), "overflow")
 	assert.Equal(t, overflowElement.ActionID, "test")
 	assert.Equal(t, len(overflowElement.Options), 3)
 
@@ -80,7 +80,7 @@ func TestNewDatePickerBlockElement(t *testing.T) {
 
 	datepickerElement := NewDatePickerBlockElement("test")
 
-	assert.Equal(t, datepickerElement.Type, "datepicker")
+	assert.Equal(t, string(datepickerElement.Type), "datepicker")
 	assert.Equal(t, datepickerElement.ActionID, "test")
 
 }