add cover image support (#7)

pkg/epub/book.go

@@ -11,12 +11,15 @@ import (
 
 // Book epub book
 type Book struct {
-	Ncx       Ncx       `json:"ncx"`
-	Opf       Opf       `json:"opf"`
-	Container Container `json:"-"`
-	Mimetype  string    `json:"-"`
-	Content   []Content
-	fd        *zip.ReadCloser
+	Ncx            Ncx       `json:"ncx"`
+	Opf            Opf       `json:"opf"`
+	Container      Container `json:"-"`
+	Mimetype       string    `json:"-"`
+	Content        []Content
+	fd             *zip.ReadCloser
+	CoverImage     []byte
+	CoverFile      string
+	CoverMediaType string
 }
 
 // Open open resource file

pkg/epub/open.go

@@ -45,8 +45,11 @@ func Open(fn string, dumpxml bool) (*Book, error) {
 			if err != nil {
 				return &bk, err
 			}
+		}
 
-			break
+		if mf.ID == "cover-image" {
+			bk.CoverFile = mf.Href
+			bk.CoverMediaType = mf.MediaType
 		}
 	}
 
@@ -61,13 +64,18 @@ func Open(fn string, dumpxml bool) (*Book, error) {
 			if err := ct.String(content); err != nil {
 				return &bk, err
 			}
+
+			bk.Content = append(bk.Content, ct)
+
+			if dumpxml {
+				fmt.Println(string(ct.XML))
+			}
 		}
 
-		bk.Content = append(bk.Content, ct)
-
-		if dumpxml {
-			fmt.Println(string(ct.XML))
+		if strings.Contains(file, bk.CoverFile) {
+			bk.CoverImage = content
 		}
+
 	}
 
 	if dumpxml {