Merge pull request #1139 from ejulio-ts/gh-821-ppt

GH 821: PowerPoint Export

ci/release/changelogs/next.md

@@ -1,5 +1,7 @@
 #### Features 🚀
 
+- Export diagrams to `.pptx` (PowerPoint)[#1139](https://github.com/terrastruct/d2/pull/1139)
+
 #### Improvements 🧹
 
 #### Bugfixes ⛑️

d2cli/main.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"os/user"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -34,6 +35,7 @@ import (
 	"oss.terrastruct.com/d2/lib/pdf"
 	pdflib "oss.terrastruct.com/d2/lib/pdf"
 	"oss.terrastruct.com/d2/lib/png"
+	"oss.terrastruct.com/d2/lib/pptx"
 	"oss.terrastruct.com/d2/lib/textmeasure"
 	"oss.terrastruct.com/d2/lib/version"
 
@@ -234,7 +236,7 @@ func Run(ctx context.Context, ms *xmain.State) (err error) {
 	ms.Log.Debug.Printf("using layout plugin %s (%s)", *layoutFlag, plocation)
 
 	var pw png.Playwright
-	if filepath.Ext(outputPath) == ".png" || filepath.Ext(outputPath) == ".pdf" {
+	if filepath.Ext(outputPath) == ".png" || filepath.Ext(outputPath) == ".pdf" || filepath.Ext(outputPath) == ".pptx" {
 		if darkThemeFlag != nil {
 			ms.Log.Warn.Printf("--dark-theme cannot be used while exporting to another format other than .svg")
 			darkThemeFlag = nil
@@ -347,7 +349,8 @@ func compile(ctx context.Context, ms *xmain.State, plugin d2plugin.Plugin, rende
 		return nil, false, err
 	}
 
-	if filepath.Ext(outputPath) == ".pdf" {
+	switch filepath.Ext(outputPath) {
+	case ".pdf":
 		pageMap := pdf.BuildPDFPageMap(diagram, nil, nil)
 		pdf, err := renderPDF(ctx, ms, plugin, renderOpts, outputPath, page, ruler, diagram, nil, nil, pageMap)
 		if err != nil {
@@ -356,7 +359,27 @@ func compile(ctx context.Context, ms *xmain.State, plugin d2plugin.Plugin, rende
 		dur := time.Since(start)
 		ms.Log.Success.Printf("successfully compiled %s to %s in %s", ms.HumanPath(inputPath), ms.HumanPath(outputPath), dur)
 		return pdf, true, nil
-	} else {
+	case ".pptx":
+		var username string
+		if user, err := user.Current(); err == nil {
+			username = user.Username
+		}
+		description := "Presentation generated with D2 - https://d2lang.com/"
+		rootName := getFileName(outputPath)
+		// version must be only numbers to avoid issues with PowerPoint
+		p := pptx.NewPresentation(rootName, description, rootName, username, version.OnlyNumbers())
+		svg, err := renderPPTX(ctx, ms, p, plugin, renderOpts, outputPath, page, diagram, nil)
+		if err != nil {
+			return nil, false, err
+		}
+		err = p.SaveTo(outputPath)
+		if err != nil {
+			return nil, false, err
+		}
+		dur := time.Since(start)
+		ms.Log.Success.Printf("successfully compiled %s to %s in %s", ms.HumanPath(inputPath), ms.HumanPath(outputPath), dur)
+		return svg, true, nil
+	default:
 		compileDur := time.Since(start)
 		if animateInterval <= 0 {
 			// Rename all the "root.layers.x" to the paths that the boards get output to
@@ -651,11 +674,7 @@ func renderPDF(ctx context.Context, ms *xmain.State, plugin d2plugin.Plugin, opt
 	var currBoardPath []string
 	// Root board doesn't have a name, so we use the output filename
 	if diagram.Name == "" {
-		ext := filepath.Ext(outputPath)
+		currBoardPath = append(boardPath, getFileName(outputPath))
-		trimmedPath := strings.TrimSuffix(outputPath, ext)
-		splitPath := strings.Split(trimmedPath, "/")
-		rootName := splitPath[len(splitPath)-1]
-		currBoardPath = append(boardPath, rootName)
 	} else {
 		currBoardPath = append(boardPath, diagram.Name)
 	}
@@ -738,6 +757,77 @@ func renderPDF(ctx context.Context, ms *xmain.State, plugin d2plugin.Plugin, opt
 	return svg, nil
 }
 
+func renderPPTX(ctx context.Context, ms *xmain.State, presentation *pptx.Presentation, plugin d2plugin.Plugin, opts d2svg.RenderOpts, outputPath string, page playwright.Page, diagram *d2target.Diagram, boardPath []string) ([]byte, error) {
+	var currBoardPath []string
+	// Root board doesn't have a name, so we use the output filename
+	if diagram.Name == "" {
+		currBoardPath = append(boardPath, getFileName(outputPath))
+	} else {
+		currBoardPath = append(boardPath, diagram.Name)
+	}
+
+	var svg []byte
+	if !diagram.IsFolderOnly {
+		// gofpdf will print the png img with a slight filter
+		// make the bg fill within the png transparent so that the pdf bg fill is the only bg color present
+		diagram.Root.Fill = "transparent"
+
+		var err error
+		svg, err = d2svg.Render(diagram, &d2svg.RenderOpts{
+			Pad:           opts.Pad,
+			Sketch:        opts.Sketch,
+			Center:        opts.Center,
+			SetDimensions: true,
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		svg, err = plugin.PostProcess(ctx, svg)
+		if err != nil {
+			return nil, err
+		}
+
+		svg, bundleErr := imgbundler.BundleLocal(ctx, ms, svg)
+		svg, bundleErr2 := imgbundler.BundleRemote(ctx, ms, svg)
+		bundleErr = multierr.Combine(bundleErr, bundleErr2)
+		if bundleErr != nil {
+			return nil, bundleErr
+		}
+
+		pngImg, err := png.ConvertSVG(ms, page, svg)
+		if err != nil {
+			return nil, err
+		}
+
+		err = presentation.AddSlide(pngImg, currBoardPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	for _, dl := range diagram.Layers {
+		_, err := renderPPTX(ctx, ms, presentation, plugin, opts, "", page, dl, currBoardPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+	for _, dl := range diagram.Scenarios {
+		_, err := renderPPTX(ctx, ms, presentation, plugin, opts, "", page, dl, currBoardPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+	for _, dl := range diagram.Steps {
+		_, err := renderPPTX(ctx, ms, presentation, plugin, opts, "", page, dl, currBoardPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return svg, nil
+}
+
 // newExt must include leading .
 func renameExt(fp string, newExt string) string {
 	ext := filepath.Ext(fp)
@@ -748,6 +838,11 @@ func renameExt(fp string, newExt string) string {
 	}
 }
 
+func getFileName(path string) string {
+	ext := filepath.Ext(path)
+	return strings.TrimSuffix(filepath.Base(path), ext)
+}
+
 // TODO: remove after removing slog
 func DiscardSlog(ctx context.Context) context.Context {
 	return ctxlog.With(ctx, slog.Make(sloghuman.Sink(io.Discard)))

e2etests-cli/main_test.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"oss.terrastruct.com/d2/d2cli"
+	"oss.terrastruct.com/d2/lib/pptx"
 	"oss.terrastruct.com/util-go/assert"
 	"oss.terrastruct.com/util-go/diff"
 	"oss.terrastruct.com/util-go/xmain"
@@ -244,6 +245,33 @@ layers: {
 				testdataIgnoreDiff(t, ".pdf", pdf)
 			},
 		},
+		{
+			name:   "how_to_solve_problems_pptx",
+			skipCI: true,
+			run: func(t *testing.T, ctx context.Context, dir string, env *xos.Env) {
+				writeFile(t, dir, "in.d2", `how to solve a hard problem?
+steps: {
+	1: {
+		w: write down the problem
+	}
+	2: {
+		w -> t
+		t: think really hard about it
+	}
+	3: {
+		t -> w2
+		w2: write down the solution
+	}
+}
+`)
+				err := runTestMain(t, ctx, dir, env, "in.d2", "how_to_solve_problems.pptx")
+				assert.Success(t, err)
+
+				file := readFile(t, dir, "how_to_solve_problems.pptx")
+				err = pptx.Validate(file, 4)
+				assert.Success(t, err)
+			},
+		},
 		{
 			name: "stdin",
 			run: func(t *testing.T, ctx context.Context, dir string, env *xos.Env) {

lib/pptx/pptx.go

@@ -0,0 +1,380 @@
+// pptx is a package to create slide presentations in pptx (Microsoft Power Point) format.
+// A `.pptx` file is just a bunch of zip compressed `.xml` files following the Office Open XML (OOXML) format.
+// To see its content, you can just `unzip <path/to/file>.pptx -d <folder>`.
+// With this package, it is possible to create a `Presentation` and add `Slide`s to it.
+// Then, when saving the presentation, it will generate the required `.xml` files, compress them and write to the disk.
+// Note that this isn't a full implementation of the OOXML format, but a wrapper around it.
+// There's a base template with common files to the presentation and then when saving, the package generate only the slides and relationships.
+// The base template and slide templates were generated using https://python-pptx.readthedocs.io/en/latest/
+// For more information about OOXML, check http://officeopenxml.com/index.php
+package pptx
+
+import (
+	"archive/zip"
+	"bytes"
+	_ "embed"
+	"fmt"
+	"image/png"
+	"os"
+	"strings"
+	"text/template"
+	"time"
+)
+
+type Presentation struct {
+	Title       string
+	Description string
+	Subject     string
+	Creator     string
+	// D2Version can't have letters, only numbers (`[0-9]`) and `.`
+	// Otherwise, it may fail to open in PowerPoint
+	D2Version string
+
+	Slides []*Slide
+}
+
+type Slide struct {
+	BoardPath   []string
+	Image       []byte
+	ImageWidth  int
+	ImageHeight int
+	ImageTop    int
+	ImageLeft   int
+}
+
+func NewPresentation(title, description, subject, creator, d2Version string) *Presentation {
+	return &Presentation{
+		Title:       title,
+		Description: description,
+		Subject:     subject,
+		Creator:     creator,
+		D2Version:   d2Version,
+	}
+}
+
+func (p *Presentation) AddSlide(pngContent []byte, boardPath []string) error {
+	src, err := png.Decode(bytes.NewReader(pngContent))
+	if err != nil {
+		return fmt.Errorf("error decoding PNG image: %v", err)
+	}
+
+	var width, height int
+	srcSize := src.Bounds().Size()
+	srcWidth, srcHeight := float64(srcSize.X), float64(srcSize.Y)
+
+	// compute the size and position to fit the slide
+	// if the image is wider than taller and its aspect ratio is, at least, the same as the available image space aspect ratio
+	// then, set the image width to the available space and compute the height
+	// ┌──────────────────────────────────────────────────┐   ─┬─
+	// │  HEADER                                          │    │
+	// ├──┬────────────────────────────────────────────┬──┤    │         ─┬─
+	// │  │                                            │  │    │          │
+	// │  │                                            │  │  SLIDE        │
+	// │  │                                            │  │  HEIGHT       │
+	// │  │                                            │  │    │        IMAGE
+	// │  │                                            │  │    │        HEIGHT
+	// │  │                                            │  │    │          │
+	// │  │                                            │  │    │          │
+	// │  │                                            │  │    │          │
+	// │  │                                            │  │    │          │
+	// └──┴────────────────────────────────────────────┴──┘   ─┴─        ─┴─
+	// ├────────────────────SLIDE WIDTH───────────────────┤
+	//    ├─────────────────IMAGE WIDTH────────────────┤
+	if srcWidth/srcHeight >= IMAGE_ASPECT_RATIO {
+		// here, the image aspect ratio is, at least, equal to the slide aspect ratio
+		// so, it makes sense to expand the image horizontally to use as much as space as possible
+		width = SLIDE_WIDTH
+		height = int(float64(width) * (srcHeight / srcWidth))
+		// first, try to make the image as wide as the slide
+		// but, if this results in a tall image, use only the
+		// image adjusted width to avoid overlapping with the header
+		if height > IMAGE_HEIGHT {
+			width = IMAGE_WIDTH
+			height = int(float64(width) * (srcHeight / srcWidth))
+		}
+	} else {
+		// here, the aspect ratio could be 4x3, in which the image is still wider than taller,
+		// but expanding horizontally would result in an overflow
+		// so, we expand to make it fit the available vertical space
+		height = IMAGE_HEIGHT
+		width = int(float64(height) * (srcWidth / srcHeight))
+	}
+	top := (IMAGE_HEIGHT - height) / 2
+	left := (SLIDE_WIDTH - width) / 2
+
+	slide := &Slide{
+		BoardPath:   make([]string, len(boardPath)),
+		Image:       pngContent,
+		ImageWidth:  width,
+		ImageHeight: height,
+		ImageTop:    top,
+		ImageLeft:   left,
+	}
+	// it must copy the board path to avoid slice reference issues
+	copy(slide.BoardPath, boardPath)
+
+	p.Slides = append(p.Slides, slide)
+	return nil
+}
+
+func (p *Presentation) SaveTo(filePath string) error {
+	f, err := os.Create(filePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	zipWriter := zip.NewWriter(f)
+	defer zipWriter.Close()
+
+	if err = copyPptxTemplateTo(zipWriter); err != nil {
+		return err
+	}
+
+	var slideFileNames []string
+	for i, slide := range p.Slides {
+		imageID := fmt.Sprintf("slide%dImage", i+1)
+		slideFileName := fmt.Sprintf("slide%d", i+1)
+		slideFileNames = append(slideFileNames, slideFileName)
+
+		imageWriter, err := zipWriter.Create(fmt.Sprintf("ppt/media/%s.png", imageID))
+		if err != nil {
+			return err
+		}
+		_, err = imageWriter.Write(slide.Image)
+		if err != nil {
+			return err
+		}
+
+		err = addFileFromTemplate(zipWriter, fmt.Sprintf("ppt/slides/_rels/%s.xml.rels", slideFileName), RELS_SLIDE_XML, RelsSlideXmlContent{
+			FileName:       imageID,
+			RelationshipID: imageID,
+		})
+		if err != nil {
+			return err
+		}
+
+		err = addFileFromTemplate(zipWriter, fmt.Sprintf("ppt/slides/%s.xml", slideFileName), SLIDE_XML, getSlideXmlContent(imageID, slide))
+		if err != nil {
+			return err
+		}
+	}
+
+	err = addFileFromTemplate(zipWriter, "[Content_Types].xml", CONTENT_TYPES_XML, ContentTypesXmlContent{
+		FileNames: slideFileNames,
+	})
+	if err != nil {
+		return err
+	}
+
+	err = addFileFromTemplate(zipWriter, "ppt/_rels/presentation.xml.rels", RELS_PRESENTATION_XML, getRelsPresentationXmlContent(slideFileNames))
+	if err != nil {
+		return err
+	}
+
+	err = addFileFromTemplate(zipWriter, "ppt/presentation.xml", PRESENTATION_XML, getPresentationXmlContent(slideFileNames))
+	if err != nil {
+		return err
+	}
+
+	dateTime := time.Now().Format(time.RFC3339)
+	err = addFileFromTemplate(zipWriter, "docProps/core.xml", CORE_XML, CoreXmlContent{
+		Creator:        p.Creator,
+		Subject:        p.Subject,
+		Description:    p.Description,
+		LastModifiedBy: p.Creator,
+		Title:          p.Title,
+		Created:        dateTime,
+		Modified:       dateTime,
+	})
+	if err != nil {
+		return err
+	}
+
+	titles := make([]string, 0, len(p.Slides))
+	for _, slide := range p.Slides {
+		titles = append(titles, strings.Join(slide.BoardPath, "/"))
+	}
+	err = addFileFromTemplate(zipWriter, "docProps/app.xml", APP_XML, AppXmlContent{
+		SlideCount:         len(p.Slides),
+		TitlesOfPartsCount: len(p.Slides) + 3,
+		D2Version:          p.D2Version,
+		Titles:             titles,
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Measurements in OOXML are made in English Metric Units (EMUs) where 1 inch = 914,400 EMUs
+// The intent is to have a measurement unit that doesn't require floating points when dealing with centimeters, inches, points (DPI).
+// Office Open XML (OOXML) http://officeopenxml.com/prPresentation.php
+// https://startbigthinksmall.wordpress.com/2010/01/04/points-inches-and-emus-measuring-units-in-office-open-xml/
+const SLIDE_WIDTH = 9_144_000
+const SLIDE_HEIGHT = 5_143_500
+const HEADER_HEIGHT = 392_471
+
+const IMAGE_HEIGHT = SLIDE_HEIGHT - HEADER_HEIGHT
+
+// keep the right aspect ratio: SLIDE_WIDTH / SLIDE_HEIGHT = IMAGE_WIDTH / IMAGE_HEIGHT
+const IMAGE_WIDTH = 8_446_273
+const IMAGE_ASPECT_RATIO = float64(IMAGE_WIDTH) / float64(IMAGE_HEIGHT)
+
+//go:embed template.pptx
+var PPTX_TEMPLATE []byte
+
+func copyPptxTemplateTo(w *zip.Writer) error {
+	reader := bytes.NewReader(PPTX_TEMPLATE)
+	zipReader, err := zip.NewReader(reader, reader.Size())
+	if err != nil {
+		fmt.Printf("error creating zip reader: %v", err)
+	}
+
+	for _, f := range zipReader.File {
+		if err := w.Copy(f); err != nil {
+			return fmt.Errorf("error copying %s: %v", f.Name, err)
+		}
+	}
+	return nil
+}
+
+//go:embed templates/slide.xml.rels
+var RELS_SLIDE_XML string
+
+type RelsSlideXmlContent struct {
+	FileName       string
+	RelationshipID string
+}
+
+//go:embed templates/slide.xml
+var SLIDE_XML string
+
+type SlideXmlContent struct {
+	Title        string
+	TitlePrefix  string
+	Description  string
+	HeaderHeight int
+	ImageID      string
+	ImageLeft    int
+	ImageTop     int
+	ImageWidth   int
+	ImageHeight  int
+}
+
+func getSlideXmlContent(imageID string, slide *Slide) SlideXmlContent {
+	boardPath := slide.BoardPath
+	boardName := boardPath[len(boardPath)-1]
+	prefixPath := boardPath[:len(boardPath)-1]
+	var prefix string
+	if len(prefixPath) > 0 {
+		prefix = strings.Join(prefixPath, "  /  ") + "  /  "
+	}
+	return SlideXmlContent{
+		Title:        boardName,
+		TitlePrefix:  prefix,
+		Description:  strings.Join(boardPath, " / "),
+		HeaderHeight: HEADER_HEIGHT,
+		ImageID:      imageID,
+		ImageLeft:    slide.ImageLeft,
+		ImageTop:     slide.ImageTop + HEADER_HEIGHT,
+		ImageWidth:   slide.ImageWidth,
+		ImageHeight:  slide.ImageHeight,
+	}
+}
+
+//go:embed templates/rels_presentation.xml
+var RELS_PRESENTATION_XML string
+
+type RelsPresentationSlideXmlContent struct {
+	RelationshipID string
+	FileName       string
+}
+
+type RelsPresentationXmlContent struct {
+	Slides []RelsPresentationSlideXmlContent
+}
+
+func getRelsPresentationXmlContent(slideFileNames []string) RelsPresentationXmlContent {
+	var content RelsPresentationXmlContent
+	for _, name := range slideFileNames {
+		content.Slides = append(content.Slides, RelsPresentationSlideXmlContent{
+			RelationshipID: name,
+			FileName:       name,
+		})
+	}
+
+	return content
+}
+
+//go:embed templates/content_types.xml
+var CONTENT_TYPES_XML string
+
+type ContentTypesXmlContent struct {
+	FileNames []string
+}
+
+//go:embed templates/presentation.xml
+var PRESENTATION_XML string
+
+type PresentationSlideXmlContent struct {
+	ID             int
+	RelationshipID string
+}
+
+type PresentationXmlContent struct {
+	SlideWidth  int
+	SlideHeight int
+	Slides      []PresentationSlideXmlContent
+}
+
+func getPresentationXmlContent(slideFileNames []string) PresentationXmlContent {
+	content := PresentationXmlContent{
+		SlideWidth:  SLIDE_WIDTH,
+		SlideHeight: SLIDE_HEIGHT,
+	}
+	for i, name := range slideFileNames {
+		content.Slides = append(content.Slides, PresentationSlideXmlContent{
+			// in the exported presentation, the first slide ID was 256, so keeping it here for compatibility
+			ID:             256 + i,
+			RelationshipID: name,
+		})
+	}
+	return content
+}
+
+//go:embed templates/core.xml
+var CORE_XML string
+
+type CoreXmlContent struct {
+	Title          string
+	Subject        string
+	Creator        string
+	Description    string
+	LastModifiedBy string
+	Created        string
+	Modified       string
+}
+
+//go:embed templates/app.xml
+var APP_XML string
+
+type AppXmlContent struct {
+	SlideCount         int
+	TitlesOfPartsCount int
+	Titles             []string
+	D2Version          string
+}
+
+func addFileFromTemplate(zipFile *zip.Writer, filePath, templateContent string, templateData interface{}) error {
+	w, err := zipFile.Create(filePath)
+	if err != nil {
+		return err
+	}
+
+	tmpl, err := template.New(filePath).Parse(templateContent)
+	if err != nil {
+		return err
+	}
+	return tmpl.Execute(w, templateData)
+}

lib/pptx/templates/app.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Properties xmlns="http://schemas.openxmlformats.org/officeDocument/2006/extended-properties"
+    xmlns:vt="http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes">
+    <TotalTime>1</TotalTime>
+    <Words>0</Words>
+    <Application>D2</Application>
+    <PresentationFormat>On-screen Show (16:9)</PresentationFormat>
+    <Paragraphs>0</Paragraphs>
+    <Slides>{{.SlideCount}}</Slides>
+    <Notes>0</Notes>
+    <HiddenSlides>0</HiddenSlides>
+    <MMClips>0</MMClips>
+    <ScaleCrop>false</ScaleCrop>
+    <HeadingPairs>
+        <vt:vector size="6" baseType="variant">
+            <vt:variant>
+                <vt:lpstr>Fonts</vt:lpstr>
+            </vt:variant>
+            <vt:variant>
+                <vt:i4>2</vt:i4>
+            </vt:variant>
+            <vt:variant>
+                <vt:lpstr>Theme</vt:lpstr>
+            </vt:variant>
+            <vt:variant>
+                <vt:i4>1</vt:i4>
+            </vt:variant>
+            <vt:variant>
+                <vt:lpstr>Slide Titles</vt:lpstr>
+            </vt:variant>
+            <vt:variant>
+                <vt:i4>{{.SlideCount}}</vt:i4>
+            </vt:variant>
+        </vt:vector>
+    </HeadingPairs>
+    <TitlesOfParts>
+        <vt:vector size="{{.TitlesOfPartsCount}}" baseType="lpstr">
+            <vt:lpstr>Arial</vt:lpstr>
+            <vt:lpstr>Calibri</vt:lpstr>
+            <vt:lpstr>Office Theme</vt:lpstr>
+            {{range .Titles}}
+            <vt:lpstr>{{.}}</vt:lpstr>
+            {{end}}
+        </vt:vector>
+    </TitlesOfParts>
+    <LinksUpToDate>false</LinksUpToDate>
+    <SharedDoc>false</SharedDoc>
+    <HyperlinkBase></HyperlinkBase>
+    <HyperlinksChanged>false</HyperlinksChanged>
+    <AppVersion>{{.D2Version}}</AppVersion>
+</Properties>

lib/pptx/templates/content_types.xml

@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
+    <Default
+        Extension="jpeg" ContentType="image/jpeg" />
+        <Default Extension="png" ContentType="image/png" />
+        <Default
+        Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml" />
+        <Default
+        Extension="xml" ContentType="application/xml" />
+        <Override PartName="/docProps/app.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.extended-properties+xml" />
+        <Override
+        PartName="/docProps/core.xml"
+        ContentType="application/vnd.openxmlformats-package.core-properties+xml" />
+        <Override
+        PartName="/ppt/presProps.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.presProps+xml" />
+        <Override
+        PartName="/ppt/presentation.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.presentation.main+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout1.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout10.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout11.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout2.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout3.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout4.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout5.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout6.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout7.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout8.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideLayouts/slideLayout9.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml" />
+        <Override
+        PartName="/ppt/slideMasters/slideMaster1.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.slideMaster+xml" />
+        {{range .FileNames}}
+        <Override PartName="/ppt/slides/{{.}}.xml" ContentType="application/vnd.openxmlformats-officedocument.presentationml.slide+xml" />
+        {{end}} 
+        <Override PartName="/ppt/tableStyles.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.tableStyles+xml" />
+        <Override
+        PartName="/ppt/theme/theme1.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.theme+xml" />
+        <Override
+        PartName="/ppt/viewProps.xml"
+        ContentType="application/vnd.openxmlformats-officedocument.presentationml.viewProps+xml" />
+</Types>

lib/pptx/templates/core.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<cp:coreProperties
+    xmlns:cp="http://schemas.openxmlformats.org/package/2006/metadata/core-properties"
+    xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/"
+    xmlns:dcmitype="http://purl.org/dc/dcmitype/"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <dc:title>{{.Title}}</dc:title>
+    <dc:subject>{{.Subject}}</dc:subject>
+    <dc:creator>{{.Creator}}</dc:creator>
+    <cp:keywords />
+    <dc:description>{{.Description}}</dc:description>
+    <cp:lastModifiedBy>{{.LastModifiedBy}}</cp:lastModifiedBy>
+    <cp:revision>1</cp:revision>
+    <dcterms:created xsi:type="dcterms:W3CDTF">{{.Created}}</dcterms:created>
+    <dcterms:modified xsi:type="dcterms:W3CDTF">{{.Modified}}</dcterms:modified>
+    <cp:category />
+</cp:coreProperties>

lib/pptx/templates/presentation.xml

@@ -0,0 +1,136 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<p:presentation xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main"
+    xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"
+    xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main" saveSubsetFonts="1"
+    autoCompressPictures="0">
+    <p:sldMasterIdLst>
+        <p:sldMasterId id="2147483648" r:id="rId1" />
+    </p:sldMasterIdLst>
+    <p:sldIdLst>
+        {{range .Slides}}
+        <p:sldId id="{{.ID}}" r:id="{{.RelationshipID}}" />
+        {{end}}
+    </p:sldIdLst>
+    <p:sldSz cx="{{.SlideWidth}}" cy="{{.SlideHeight}}" type="screen4x3" />
+    <p:notesSz cx="6858000" cy="9144000" />
+    <p:defaultTextStyle>
+        <a:defPPr>
+            <a:defRPr lang="en-US" />
+        </a:defPPr>
+        <a:lvl1pPr marL="0" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl1pPr>
+        <a:lvl2pPr marL="457200" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl2pPr>
+        <a:lvl3pPr marL="914400" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl3pPr>
+        <a:lvl4pPr marL="1371600" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl4pPr>
+        <a:lvl5pPr marL="1828800" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl5pPr>
+        <a:lvl6pPr marL="2286000" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl6pPr>
+        <a:lvl7pPr marL="2743200" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl7pPr>
+        <a:lvl8pPr marL="3200400" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl8pPr>
+        <a:lvl9pPr marL="3657600" algn="l" defTabSz="457200" rtl="0" eaLnBrk="1" latinLnBrk="0"
+            hangingPunct="1">
+            <a:defRPr sz="1800" kern="1200">
+                <a:solidFill>
+                    <a:schemeClr val="tx1" />
+                </a:solidFill>
+                <a:latin typeface="+mn-lt" />
+                <a:ea typeface="+mn-ea" />
+                <a:cs typeface="+mn-cs" />
+            </a:defRPr>
+        </a:lvl9pPr>
+    </p:defaultTextStyle>
+    <p:extLst>
+        <p:ext uri="{EFAFB233-063F-42B5-8137-9DF3F51BA10A}">
+            <p15:sldGuideLst xmlns:p15="http://schemas.microsoft.com/office/powerpoint/2012/main">
+                <p15:guide id="1" orient="horz" pos="2160">
+                    <p15:clr>
+                        <a:srgbClr val="A4A3A4" />
+                    </p15:clr>
+                </p15:guide>
+                <p15:guide id="2" pos="2880">
+                    <p15:clr>
+                        <a:srgbClr val="A4A3A4" />
+                    </p15:clr>
+                </p15:guide>
+            </p15:sldGuideLst>
+        </p:ext>
+    </p:extLst>
+</p:presentation>

lib/pptx/templates/rels_presentation.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+<Relationship Id="rId3"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/presProps"
+    Target="presProps.xml" />
+<Relationship Id="rId4"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/viewProps"
+    Target="viewProps.xml" />
+<Relationship Id="rId5"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme"
+    Target="theme/theme1.xml" />
+<Relationship Id="rId6"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/tableStyles"
+    Target="tableStyles.xml" />
+<Relationship Id="rId1"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/slideMaster"
+    Target="slideMasters/slideMaster1.xml" />
+    {{range .Slides}}
+    <Relationship Id="{{.RelationshipID}}" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/slide" Target="slides/{{.FileName}}.xml" />
+    {{end}}
+</Relationships>

lib/pptx/templates/slide.xml

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<p:sld xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main"
+    xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main"
+    xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
+    <p:cSld>
+        <p:spTree>
+            <p:nvGrpSpPr>
+                <p:cNvPr id="1" name="" />
+                <p:cNvGrpSpPr />
+                <p:nvPr />
+            </p:nvGrpSpPr>
+            <p:grpSpPr>
+                <a:xfrm>
+                    <a:off x="0" y="0" />
+                    <a:ext cx="0" cy="0" />
+                    <a:chOff x="0" y="0" />
+                    <a:chExt cx="0" cy="0" />
+                </a:xfrm>
+            </p:grpSpPr>
+            <p:pic>
+                <p:nvPicPr>
+                    <p:cNvPr id="2" name="{{.Description}}" descr="{{.Description}}" />
+                    <p:cNvPicPr>
+                        <a:picLocks noChangeAspect="1" />
+                    </p:cNvPicPr>
+                    <p:nvPr />
+                </p:nvPicPr>
+                <p:blipFill>
+                    <a:blip r:embed="{{.ImageID}}" />
+                    <a:stretch>
+                        <a:fillRect />
+                    </a:stretch>
+                </p:blipFill>
+                <p:spPr>
+                    <a:xfrm>
+                        <a:off x="{{.ImageLeft}}" y="{{.ImageTop}}" />
+                        <a:ext cx="{{.ImageWidth}}" cy="{{.ImageHeight}}" />
+                    </a:xfrm>
+                    <a:prstGeom prst="rect">
+                        <a:avLst />
+                    </a:prstGeom>
+                </p:spPr>
+            </p:pic>
+            <p:sp>
+                <p:nvSpPr>
+                    <p:cNvPr id="95" name="{{.Description}}" />
+                    <p:cNvSpPr txBox="1" />
+                    <p:nvPr />
+                </p:nvSpPr>
+                <p:spPr>
+                    <a:xfrm>
+                        <a:off x="4001" y="6239" />
+                        <a:ext cx="9135998" cy="{{.HeaderHeight}}" />
+                    </a:xfrm>
+                    <a:prstGeom prst="rect">
+                        <a:avLst />
+                    </a:prstGeom>
+                    <a:ln w="12700">
+                        <a:miter lim="400000" />
+                    </a:ln>
+                    <a:extLst>
+                        <a:ext uri="{C572A759-6A51-4108-AA02-DFA0A04FC94B}">
+                            <ma14:wrappingTextBoxFlag
+                                xmlns:ma14="http://schemas.microsoft.com/office/mac/drawingml/2011/main"
+                                xmlns="" val="1" />
+                        </a:ext>
+                    </a:extLst>
+                </p:spPr>
+                <p:txBody>
+                    <a:bodyPr lIns="45719" rIns="45719">
+                        <a:spAutoFit />
+                    </a:bodyPr>
+                    <a:lstStyle>
+                        <a:lvl1pPr>
+                            <a:defRPr sz="2400" />
+                        </a:lvl1pPr>
+                    </a:lstStyle>
+                    <a:p>
+                        {{if .TitlePrefix}}
+                        <a:r>
+                            <a:t>{{.TitlePrefix}}</a:t>
+                        </a:r>
+                        {{end}}
+                        <a:r>
+                            <a:rPr b="1" />
+                            <a:t>{{.Title}}</a:t>
+                        </a:r>
+                    </a:p>
+                </p:txBody>
+            </p:sp>
+        </p:spTree>
+    </p:cSld>
+    <p:clrMapOvr>
+        <a:masterClrMapping />
+    </p:clrMapOvr>
+</p:sld>

lib/pptx/templates/slide.xml.rels

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+    <Relationship Id="rId1"
+        Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/slideLayout"
+        Target="../slideLayouts/slideLayout7.xml" />
+    <Relationship Id="{{.RelationshipID}}"
+        Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
+        Target="../media/{{.FileName}}.png" />
+</Relationships>

lib/pptx/validate.go

@@ -0,0 +1,82 @@
+package pptx
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"strings"
+)
+
+func Validate(pptxContent []byte, nSlides int) error {
+	reader := bytes.NewReader(pptxContent)
+	zipReader, err := zip.NewReader(reader, reader.Size())
+	if err != nil {
+		fmt.Printf("error reading pptx content: %v", err)
+	}
+
+	expectedCount := getExpectedPptxFileCount(nSlides)
+	if len(zipReader.File) != expectedCount {
+		return fmt.Errorf("expected %d files, got %d", expectedCount, len(zipReader.File))
+	}
+
+	for i := 0; i < nSlides; i++ {
+		if err := checkFile(zipReader, fmt.Sprintf("ppt/slides/slide%d.xml", i+1)); err != nil {
+			return err
+		}
+		if err := checkFile(zipReader, fmt.Sprintf("ppt/slides/_rels/slide%d.xml.rels", i+1)); err != nil {
+			return err
+		}
+		if err := checkFile(zipReader, fmt.Sprintf("ppt/media/slide%dImage.png", i+1)); err != nil {
+			return err
+		}
+	}
+
+	for _, file := range zipReader.File {
+		if !strings.Contains(file.Name, ".xml") {
+			continue
+		}
+		// checks if the XML content is valid
+		f, err := file.Open()
+		if err != nil {
+			return fmt.Errorf("error opening %s: %v", file.Name, err)
+		}
+		decoder := xml.NewDecoder(f)
+		for {
+			if err := decoder.Decode(new(interface{})); err != nil {
+				if err == io.EOF {
+					break
+				}
+				return fmt.Errorf("error parsing xml content in %s: %v", file.Name, err)
+			}
+		}
+		defer f.Close()
+	}
+
+	return nil
+}
+
+func checkFile(reader *zip.Reader, fname string) error {
+	f, err := reader.Open(fname)
+	if err != nil {
+		return fmt.Errorf("error opening file %s: %v", fname, err)
+	}
+	defer f.Close()
+	if _, err = f.Stat(); err != nil {
+		return fmt.Errorf("error getting file info %s: %v", fname, err)
+	}
+	return nil
+}
+
+func getExpectedPptxFileCount(nSlides int) int {
+	reader := bytes.NewReader(PPTX_TEMPLATE)
+	zipReader, err := zip.NewReader(reader, reader.Size())
+	if err != nil {
+		return -1
+	}
+	baseFiles := len(zipReader.File)
+	presentationFiles := 5    // presentation, rels, app, core, content types
+	slideFiles := 3 * nSlides // slides, rels, images
+	return baseFiles + presentationFiles + slideFiles
+}

lib/version/version.go

@@ -1,4 +1,14 @@
 package version
 
+import "regexp"
+
 // Pre-built binaries will have version set correctly during build time.
 var Version = "v0.4.0-HEAD"
+
+func OnlyNumbers() string {
+	re, err := regexp.Compile("[0-9]+.[0-9]+.[0-9]+")
+	if err != nil {
+		return ""
+	}
+	return re.FindString(Version)
+}