Allow running specific code blocks

examples/code_blocks.md

@@ -65,6 +65,10 @@ fmt.Println("Hello, world!")
 console.log("Hello, world!")
 ```
 
+```javascript
+console.log("Hello, universe!")
+```
+
 ---
 
 ### Lua

internal/code/languages.go

@@ -25,7 +25,7 @@ const (
 	Python     = "python"
 	Ruby       = "ruby"
 	Rust       = "rust"
-    Java       = "java"
+	Java       = "java"
 )
 
 // Languages is a map of supported languages with their extensions and commands

internal/code/selection.go

@@ -0,0 +1 @@
+package code

internal/model/model.go

@@ -7,6 +7,8 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -48,6 +50,8 @@ type Model struct {
 	// original slides, it will be displayed on a slide and reset on page change
 	VirtualText string
 	Search      navigation.Search
+
+	blocks *navigation.Blocks
 }
 
 type fileWatchMsg struct{}
@@ -102,6 +106,7 @@ func (m *Model) Load() error {
 	if m.Theme == nil {
 		m.Theme = styles.SelectTheme(metaData.Theme)
 	}
+	m.blocks = nil
 
 	return nil
 }
@@ -140,6 +145,10 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return m, cmd
 		}
 
+		if m.blocks != nil {
+			return m.runCodeBlocks(msg)
+		}
+
 		switch keyPress {
 		case "/":
 			// Begin search
@@ -154,15 +163,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			blocks, err := code.Parse(m.Slides[m.Page])
 			if err != nil {
 				// We couldn't parse the code block on the screen
-				m.VirtualText = "\n" + err.Error()
+				m.SetVirtualText("\n" + err.Error())
 				return m, nil
 			}
-			var outs []string
-			for _, block := range blocks {
-				res := code.Execute(block)
-				outs = append(outs, res.Out)
-			}
-			m.VirtualText = strings.Join(outs, "\n")
+			m.blocks = navigation.NewBlocks(blocks)
+			return m, nil
 		case "y":
 			blocks, err := code.Parse(m.Slides[m.Page])
 			if err != nil {
@@ -236,6 +241,52 @@ func (m *Model) paging() string {
 	}
 }
 
+func (m *Model) runCodeBlocks(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.Type {
+	case tea.KeyEnter:
+		m.blocks.ExecuteNext(m)
+		if m.blocks.Done() {
+			m.blocks = nil
+		}
+		return m, nil
+	case tea.KeyCtrlC, tea.KeyEscape:
+		m.blocks = nil
+		return m, nil
+	}
+
+	keyPress := msg.String()
+	switch keyPress {
+	case "a":
+		m.blocks.ExecuteAll(m)
+		m.blocks = nil
+		return m, nil
+	case "n":
+		m.blocks.ExecuteNext(m)
+		if m.blocks.Done() {
+			m.blocks = nil
+		}
+		return m, nil
+	}
+
+	digits := regexp.MustCompile(`\d+`)
+	match := digits.FindString(keyPress)
+	if match == "" {
+		return m, nil
+	}
+
+	idx, err := strconv.Atoi(match)
+	if err != nil {
+		m.SetVirtualText("\n" + err.Error())
+		return m, nil
+	}
+
+	m.blocks.ExecuteIdx(uint(idx), m)
+	if m.blocks.Done() {
+		m.blocks = nil
+	}
+	return m, nil
+}
+
 func readFile(path string) (string, error) {
 	s, err := os.Stat(path)
 	if err != nil {
@@ -310,3 +361,8 @@ func (m *Model) SetPage(page int) {
 func (m *Model) Pages() []string {
 	return m.Slides
 }
+
+// SetVirtualText sets the virtual text for the presentation.
+func (m *Model) SetVirtualText(text string) {
+	m.VirtualText = text
+}

internal/navigation/blocks.go

@@ -0,0 +1,60 @@
+package navigation
+
+import (
+	"github.com/maaslalani/slides/internal/code"
+	"strconv"
+)
+
+type Blocks struct {
+	blocks  []code.Block
+	nextIdx uint
+	done    bool
+}
+
+func NewBlocks(blocks []code.Block) *Blocks {
+	b := new(Blocks)
+	b.blocks = blocks
+	b.nextIdx = 0
+	b.checkDone()
+
+	return b
+}
+
+func (b *Blocks) ExecuteAll(m Model) {
+	for _, block := range b.blocks {
+		res := code.Execute(block)
+		m.SetVirtualText(res.Out)
+	}
+	b.nextIdx = uint(len(b.blocks))
+	b.checkDone()
+}
+
+func (b *Blocks) ExecuteNext(m Model) {
+	if b.done {
+		return
+	}
+
+	res := code.Execute(b.blocks[b.nextIdx])
+	m.SetVirtualText(res.Out)
+
+	b.nextIdx++
+	b.checkDone()
+}
+
+func (b *Blocks) ExecuteIdx(idx uint, m Model) {
+	if idx >= uint(len(b.blocks)) {
+		m.SetVirtualText("no code block with index [" + strconv.Itoa(int(idx)) + "]")
+		return
+	}
+
+	b.nextIdx = idx
+	b.ExecuteNext(m)
+}
+
+func (b *Blocks) Done() bool {
+	return b.done
+}
+
+func (b *Blocks) checkDone() {
+	b.done = b.nextIdx >= uint(len(b.blocks))
+}

internal/navigation/blocks_test.go

@@ -0,0 +1,88 @@
+package navigation
+
+import (
+	"github.com/maaslalani/slides/internal/code"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestBlocks_ExecuteAll(t *testing.T) {
+	b := []code.Block{
+		{},
+		{},
+		{},
+	}
+	m := mockModel{}
+
+	blocks := NewBlocks(b)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteAll(&m)
+	require.True(t, blocks.Done())
+}
+
+func TestBlocks_ExecuteNext(t *testing.T) {
+	b := []code.Block{
+		{
+			Language: "javascript",
+			Code:     `console.log("first block")`,
+		},
+		{
+			Language: "javascript",
+			Code:     `console.log("second block")`,
+		},
+		{
+			Language: "javascript",
+			Code:     `console.log("third block")`,
+		},
+	}
+	m := mockModel{}
+
+	blocks := NewBlocks(b)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteNext(&m)
+	require.Equal(t, "first block\n", m.virtualText)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteNext(&m)
+	require.Equal(t, "second block\n", m.virtualText)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteNext(&m)
+	require.Equal(t, "third block\n", m.virtualText)
+	require.True(t, blocks.Done())
+}
+
+func TestBlocks_ExecuteIdx(t *testing.T) {
+	b := []code.Block{
+		{
+			Language: "javascript",
+			Code:     `console.log("first block")`,
+		},
+		{
+			Language: "javascript",
+			Code:     `console.log("second block")`,
+		},
+		{
+			Language: "javascript",
+			Code:     `console.log("third block")`,
+		},
+	}
+	m := mockModel{}
+
+	blocks := NewBlocks(b)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteIdx(1, &m)
+	require.Equal(t, "second block\n", m.virtualText)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteIdx(0, &m)
+	require.Equal(t, "first block\n", m.virtualText)
+	require.False(t, blocks.Done())
+
+	blocks.ExecuteIdx(2, &m)
+	require.Equal(t, "third block\n", m.virtualText)
+	require.True(t, blocks.Done())
+}

internal/navigation/model.go

@@ -0,0 +1,31 @@
+package navigation
+
+// Model is an interface for models.model, so that cycle imports are avoided
+type Model interface {
+	CurrentPage() int
+	SetPage(page int)
+	Pages() []string
+	SetVirtualText(string)
+}
+
+type mockModel struct {
+	slides      []string
+	page        int
+	virtualText string
+}
+
+func (m *mockModel) CurrentPage() int {
+	return m.page
+}
+
+func (m *mockModel) SetPage(page int) {
+	m.page = page
+}
+
+func (m *mockModel) Pages() []string {
+	return m.slides
+}
+
+func (m *mockModel) SetVirtualText(text string) {
+	m.virtualText = text
+}

internal/navigation/search.go

@@ -8,13 +8,6 @@ import (
 	"github.com/maaslalani/slides/styles"
 )
 
-// Model is an interface for models.model, so that cycle imports are avoided
-type Model interface {
-	CurrentPage() int
-	SetPage(page int)
-	Pages() []string
-}
-
 // Search represents the current search
 type Search struct {
 	// Active - Show search bar instead of author and date?

internal/navigation/search_test.go

@@ -4,23 +4,6 @@ import (
 	"testing"
 )
 
-type mockModel struct {
-	slides []string
-	page   int
-}
-
-func (m *mockModel) CurrentPage() int {
-	return m.page
-}
-
-func (m *mockModel) SetPage(page int) {
-	m.page = page
-}
-
-func (m *mockModel) Pages() []string {
-	return m.slides
-}
-
 func TestSearch(t *testing.T) {
 	data := []string{
 		"hi",