pptx: add support for MS PowerPoint files (#71)

pptx.go

@@ -0,0 +1,67 @@
+package docconv
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+// ConvertPptx converts an MS PowerPoint pptx file to text.
+func ConvertPptx(r io.Reader) (string, map[string]string, error) {
+	var size int64
+
+	// Common case: if the reader is a file (or trivial wrapper), avoid
+	// loading it all into memory.
+	var ra io.ReaderAt
+	if f, ok := r.(interface {
+		io.ReaderAt
+		Stat() (os.FileInfo, error)
+	}); ok {
+		si, err := f.Stat()
+		if err != nil {
+			return "", nil, err
+		}
+		size = si.Size()
+		ra = f
+	} else {
+		b, err := ioutil.ReadAll(r)
+		if err != nil {
+			return "", nil, nil
+		}
+		size = int64(len(b))
+		ra = bytes.NewReader(b)
+	}
+
+	zr, err := zip.NewReader(ra, size)
+	if err != nil {
+		return "", nil, fmt.Errorf("could not unzip: %v", err)
+	}
+
+	zipFiles := mapZipFiles(zr.File)
+
+	contentTypeDefinition, err := getContentTypeDefinition(zipFiles["[Content_Types].xml"])
+	if err != nil {
+		return "", nil, err
+	}
+
+	meta := make(map[string]string)
+	var textBody string
+	for _, override := range contentTypeDefinition.Overrides {
+		f := zipFiles[override.PartName]
+
+		switch override.ContentType {
+		case "application/vnd.openxmlformats-officedocument.presentationml.slide+xml",
+			"application/vnd.openxmlformats-officedocument.drawingml.diagramData+xml":
+			body, err := parseDocxText(f)
+			if err != nil {
+				return "", nil, fmt.Errorf("could not parse pptx: %v", err)
+			}
+			textBody += body + "\n"
+		}
+	}
+	return strings.TrimSuffix(textBody, "\n"), meta, nil
+}

pptx_test/pptx_test.go

@@ -0,0 +1,29 @@
+package docx_test
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"code.sajari.com/docconv"
+)
+
+func TestConvertPptx(t *testing.T) {
+	f, err := os.Open("./testdata/sample.pptx")
+	defer f.Close()
+
+	if err != nil {
+		t.Fatalf("got error = %v, want nil", err)
+	}
+
+	resp, _, err := docconv.ConvertPptx(f)
+	if err != nil {
+		t.Fatalf("got error = %v, want nil", err)
+	}
+	if want := "Get text from pptx"; !strings.Contains(resp, want) {
+		t.Errorf("expected %v to contain %v", resp, want)
+	}
+	if want := "First"; !strings.Contains(resp, want) {
+		t.Errorf("expected %v to contain %v", resp, want)
+	}
+}