encoding/xml: bring API closer to other packages
Includes gofix module. The only case not covered should be
xml.Unmarshal, since it remains with a similar interface, and
would require introspecting the type of its first argument
better.
Fixes #2626.
R=golang-dev, rsc, gustavo
CC=golang-dev
https://golang.org/cl/5574053
diff --git a/src/pkg/encoding/xml/marshal.go b/src/pkg/encoding/xml/marshal.go
index 7724e93..77413cb 100644
--- a/src/pkg/encoding/xml/marshal.go
+++ b/src/pkg/encoding/xml/marshal.go
@@ -26,11 +26,7 @@
MarshalXML() ([]byte, error)
}
-type printer struct {
- *bufio.Writer
-}
-
-// Marshal writes an XML-formatted representation of v to w.
+// Marshal returns the XML encoding of v.
//
// If v implements Marshaler, then Marshal calls its MarshalXML method.
// Otherwise, Marshal uses the following procedure to create the XML.
@@ -76,7 +72,7 @@
// Age int `xml:"person>age"`
// }
//
-// xml.Marshal(w, &Result{Id: 13, FirstName: "John", LastName: "Doe", Age: 42})
+// xml.Marshal(&Result{Id: 13, FirstName: "John", LastName: "Doe", Age: 42})
//
// would be marshalled as:
//
@@ -91,13 +87,38 @@
// </result>
//
// Marshal will return an error if asked to marshal a channel, function, or map.
-func Marshal(w io.Writer, v interface{}) (err error) {
- p := &printer{bufio.NewWriter(w)}
- err = p.marshalValue(reflect.ValueOf(v), nil)
- p.Flush()
+func Marshal(v interface{}) ([]byte, error) {
+ var b bytes.Buffer
+ if err := NewEncoder(&b).Encode(v); err != nil {
+ return nil, err
+ }
+ return b.Bytes(), nil
+}
+
+// An Encoder writes XML data to an output stream.
+type Encoder struct {
+ printer
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+ return &Encoder{printer{bufio.NewWriter(w)}}
+}
+
+// Encode writes the XML encoding of v to the stream.
+//
+// See the documentation for Marshal for details about the conversion
+// of Go values to XML.
+func (enc *Encoder) Encode(v interface{}) error {
+ err := enc.marshalValue(reflect.ValueOf(v), nil)
+ enc.Flush()
return err
}
+type printer struct {
+ *bufio.Writer
+}
+
func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo) error {
if !val.IsValid() {
return nil
