Add images from bytes for presentation and workbook (unidoc#295)

common/helpers.go

@@ -0,0 +1,27 @@
+package common
+
+import (
+	"archive/zip"
+	"fmt"
+	"strings"
+
+	"github.com/unidoc/unioffice"
+	"github.com/unidoc/unioffice/zippkg"
+)
+
+// AddImageToZip adds an image (either from bytes or from disk) and adds it to the zip file.
+func AddImageToZip(z *zip.Writer, img ImageRef, imageNum int, dt unioffice.DocType) error {
+	filename := unioffice.AbsoluteImageFilename(dt, imageNum, strings.ToLower(img.Format()))
+	if img.Data() != nil && len(*img.Data()) > 0 {
+		if err := zippkg.AddFileFromBytes(z, filename, *img.Data()); err != nil {
+			return err
+		}
+	} else if img.Path() != "" {
+		if err := zippkg.AddFileFromDisk(z, filename, img.Path()); err != nil {
+			return err
+		}
+	} else {
+		return fmt.Errorf("unsupported image source: %+v", img)
+	}
+	return nil
+}

document/document.go

@@ -262,17 +262,8 @@ func (d *Document) Save(w io.Writer) error {
 	}
 
 	for i, img := range d.Images {
-		fn := fmt.Sprintf("word/media/image%d.%s", i+1, strings.ToLower(img.Format()))
-		if img.Data() != nil {
-			if err := zippkg.AddFileFromBytes(z, fn, *img.Data()); err != nil {
-				return err
-			}
-		} else if img.Path() != "" {
-			if err := zippkg.AddFileFromDisk(z, fn, img.Path()); err != nil {
-				return err
-			}
-		} else {
-			unioffice.Log("unsupported image source: %+v", img)
+		if err := common.AddImageToZip(z, img, i+1, unioffice.DocTypeDocument); err != nil {
+			return err
 		}
 	}
 

filenames.go

@@ -193,3 +193,11 @@ func AbsoluteFilename(dt DocType, typ string, index int) string {
 	}
 	return ""
 }
+
+// AbsoluteImageFilename returns the full path to an image from the root of the
+// zip container.
+func AbsoluteImageFilename(dt DocType, index int, fileExtension string) string {
+	filename := AbsoluteFilename(dt, ImageType, index)
+	// replace "png" with the actual file extension
+	return filename[0:len(filename)-3] + fileExtension
+}

presentation/presentation.go

@@ -19,7 +19,6 @@ import (
 	"log"
 	"os"
 	"path"
-	"strings"
 
 	"github.com/unidoc/unioffice"
 	"github.com/unidoc/unioffice/common"
@@ -443,14 +442,8 @@ func (p *Presentation) Save(w io.Writer) error {
 	}
 
 	for i, img := range p.Images {
-		fn := unioffice.AbsoluteFilename(unioffice.DocTypePresentation, unioffice.ImageType, i+1)
-		fn = fn[0:len(fn)-3] + strings.ToLower(img.Format())
-		if img.Path() != "" {
-			if err := zippkg.AddFileFromDisk(z, fn, img.Path()); err != nil {
-				return err
-			}
-		} else {
-			unioffice.Log("unsupported image source: %+v", img)
+		if err := common.AddImageToZip(z, img, i+1, unioffice.DocTypePresentation); err != nil {
+			return err
 		}
 	}
 

spreadsheet/workbook.go

@@ -329,13 +329,8 @@ func (wb *Workbook) Save(w io.Writer) error {
 	}
 
 	for i, img := range wb.Images {
-		fn := fmt.Sprintf("xl/media/image%d.%s", i+1, img.Format())
-		if img.Path() != "" {
-			if err := zippkg.AddFileFromDisk(z, fn, img.Path()); err != nil {
-				return err
-			}
-		} else {
-			unioffice.Log("unsupported image source: %+v", img)
+		if err := common.AddImageToZip(z, img, i+1, unioffice.DocTypeSpreadsheet); err != nil {
+			return err
 		}
 	}