Add AllTags function to Xmp (#7)

* Add AllTags function to Xmp

exif.go

@@ -106,7 +106,7 @@ func (d *ExifDatum) String() string {
 	return C.GoString(cstr)
 }
 
-// Returns all EXIF tags
+// AllTags returns all EXIF tags
 func (d *ExifData) AllTags() map[string]string {
 	keyValues := map[string]string{}
 	for i := d.Iterator(); i.HasNext(); {
@@ -132,6 +132,7 @@ func (i *ExifDatumIterator) Next() *ExifDatum {
 	return makeExifDatum(i.data, C.exiv2_exif_datum_iterator_next(i.iter))
 }
 
+// makeExifDatumIterator creates a new ExifDatumIterator and sets a finalizer to free the C++ object.
 func makeExifDatumIterator(data *ExifData, cIter *C.Exiv2ExifDatumIterator) *ExifDatumIterator {
 	datum := &ExifDatumIterator{data, cIter}
 

exiv.go

@@ -143,7 +143,7 @@ func (i *Image) ReadMetadata() error {
 	return nil
 }
 
-// Returns an image contents.
+// GetBytes returns an image contents.
 // If its metadata has been changed, the changes are reflected here.
 func (i *Image) GetBytes() []byte {
 	size := C.exiv_image_get_size(i.img)
@@ -233,6 +233,7 @@ func (i *Image) SetMetadataShort(f MetadataFormat, key, value string) error {
 	return nil
 }
 
+// StripKey removes a key from the metadata
 func (i *Image) StripKey(f MetadataFormat, key string) error {
 	ckey := C.CString(key)
 	defer C.free(unsafe.Pointer(ckey))
@@ -259,6 +260,7 @@ func (i *Image) StripKey(f MetadataFormat, key string) error {
 	return nil
 }
 
+// StripMetadata removes all metadata from the image except the keys in unless
 func (i *Image) StripMetadata(unless []string) error {
 	var err error
 	err = i.ExifStripMetadata(unless)

exiv_test.go

@@ -4,7 +4,7 @@ import (
 	"github.com/rtio/goexiv"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"io/ioutil"
+	"os"
 	"runtime"
 	"sync"
 	"testing"
@@ -42,7 +42,7 @@ func TestOpenImage(t *testing.T) {
 }
 
 func Test_OpenBytes(t *testing.T) {
-	bytes, err := ioutil.ReadFile("testdata/pixel.jpg")
+	bytes, err := os.ReadFile("testdata/pixel.jpg")
 	require.NoError(t, err)
 
 	img, err := goexiv.OpenBytes(bytes)
@@ -173,6 +173,16 @@ func TestMetadata(t *testing.T) {
 		"Iptc.Application2.DateCreated": "2012-10-13",
 		"Iptc.Application2.TimeCreated": "12:49:32+01:00",
 	}, iptcData.AllTags())
+
+	//
+	// XMP
+	//
+	xmpData := img.GetXmpData()
+	assert.Equal(t, map[string]string{
+		"Xmp.iptc.CopyrightNotice": "this is the copy, right?",
+		"Xmp.iptc.CreditLine":      "John Doe",
+		"Xmp.iptc.JobId":           "12345",
+	}, xmpData.AllTags())
 }
 
 func TestNoMetadata(t *testing.T) {
@@ -398,7 +408,7 @@ func Test_SetMetadataShortInt(t *testing.T) {
 }
 
 func Test_GetBytes(t *testing.T) {
-	bytes, err := ioutil.ReadFile("testdata/stripped_pixel.jpg")
+	bytes, err := os.ReadFile("testdata/stripped_pixel.jpg")
 	require.NoError(t, err)
 
 	img, err := goexiv.OpenBytes(bytes)
@@ -432,7 +442,7 @@ func Test_GetBytes_Goroutine(t *testing.T) {
 	var wg sync.WaitGroup
 	iterations := 0
 
-	bytes, err := ioutil.ReadFile("testdata/stripped_pixel.jpg")
+	bytes, err := os.ReadFile("testdata/stripped_pixel.jpg")
 	require.NoError(t, err)
 
 	for i := 0; i < 100; i++ {
@@ -681,7 +691,7 @@ func BenchmarkImage_GetBytes_KeepAlive(b *testing.B) {
 }
 
 func BenchmarkImage_GetBytes_NoKeepAlive(b *testing.B) {
-	bytes, err := ioutil.ReadFile("testdata/stripped_pixel.jpg")
+	bytes, err := os.ReadFile("testdata/stripped_pixel.jpg")
 	require.NoError(b, err)
 	var wg sync.WaitGroup
 
@@ -728,4 +738,8 @@ func initializeImage(path string, t *testing.T) {
 		err = img.SetExifString(k, v)
 		require.NoError(t, err, k, v)
 	}
+
+	img.SetXmpString("Xmp.iptc.CreditLine", "John Doe")
+	img.SetXmpString("Xmp.iptc.CopyrightNotice", "this is the copy, right?")
+	img.SetXmpString("Xmp.iptc.JobId", "12345")
 }

iptc.go

@@ -110,7 +110,7 @@ func (d *IptcDatum) String() string {
 	return C.GoString(cstr)
 }
 
-// Returns all IPTC tags
+// AllTags returns all IPTC tags
 func (d *IptcData) AllTags() map[string]string {
 	keyValues := map[string]string{}
 	for i := d.Iterator(); i.HasNext(); {
@@ -136,6 +136,7 @@ func (i *IptcDatumIterator) Next() *IptcDatum {
 	return makeIptcDatum(i.data, C.exiv2_iptc_datum_iterator_next(i.iter))
 }
 
+// makeIptcDatumIterator creates a new IptcDatumIterator.
 func makeIptcDatumIterator(data *IptcData, cIter *C.Exiv2IptcDatumIterator) *IptcDatumIterator {
 	datum := &IptcDatumIterator{data, cIter}