Enhance documentation and add test for PDF417 barcode

1 files changed, 8 insertions, 5 deletions

diff --git a/contrib/barcode/barcode.go b/contrib/barcode/barcode.go
index faed915..b2ba2c2 100644
--- a/contrib/barcode/barcode.go
+++ b/contrib/barcode/barcode.go
@@ -32,8 +32,8 @@ import (
 	"github.com/boombuler/barcode/ean"
 	"github.com/boombuler/barcode/qr"
 	"github.com/boombuler/barcode/twooffive"
-	"github.com/ruudk/golang-pdf417"
 	"github.com/jung-kurt/gofpdf"
+	"github.com/ruudk/golang-pdf417"
 )
 
 // barcodes represents the barcodes that have been registered through this
@@ -132,12 +132,15 @@ func RegisterDataMatrix(pdf barcodePdf, code string) string {
 	return registerBarcode(pdf, bcode, err)
 }
 
-// RegisterPdf417 registers a barcode of type Pdf417 to the PDF, but not
-// to the page. Use Barcode() with the return value to put the barcode on the
-// page.
+// RegisterPdf417 registers a barcode of type Pdf417 to the PDF, but not to the
+// page. code is the string to be encoded. columns specifies the number of
+// barcode columns; this should be a value between 1 and 30 inclusive.
+// securityLevel specifies an error correction level between zero and 8
+// inclusive. Barcodes for use with FedEx must set columns to 10 and
+// securityLevel to 5. Use Barcode() with the return value to put the barcode
+// on the page.
 func RegisterPdf417(pdf barcodePdf, code string, columns int, securityLevel int) string {
 	bcode := pdf417.Encode(code, columns, securityLevel)
-
 	return registerBarcode(pdf, bcode, nil)
 }