Add namespace helper functions for Element and Attr.

Added Element.FullTag() to request the full tag of an element
including namespace, if any.

Added Attr.FullKey() to request the full key name of an
attribute including namespace, if any.

1 files changed, 23 insertions, 21 deletions

diff --git a/etree.go b/etree.go
index 2968da1..98f5609 100644
--- a/etree.go
+++ b/etree.go
@@ -350,6 +350,15 @@ func (e *Element) Copy() *Element {
 	return e.dup(nil).(*Element)
 }
 
+// FullTag returns the element e's complete tag, including namespace prefix if
+// present.
+func (e *Element) FullTag() string {
+	if e.Space == "" {
+		return e.Tag
+	}
+	return e.Space + ":" + e.Tag
+}
+
 // NamespaceURI returns the XML namespace URI associated with the element. If
 // the element is part of the XML default namespace, NamespaceURI returns the
 // empty string.
@@ -983,11 +992,7 @@ func (e *Element) setIndex(index int) {
 // writeTo serializes the element to the writer w.
 func (e *Element) writeTo(w *bufio.Writer, s *WriteSettings) {
 	w.WriteByte('<')
-	if e.Space != "" {
-		w.WriteString(e.Space)
-		w.WriteByte(':')
-	}
-	w.WriteString(e.Tag)
+	w.WriteString(e.FullTag())
 	for _, a := range e.Attr {
 		w.WriteByte(' ')
 		a.writeTo(w, s)
@@ -998,20 +1003,12 @@ func (e *Element) writeTo(w *bufio.Writer, s *WriteSettings) {
 			c.writeTo(w, s)
 		}
 		w.Write([]byte{'<', '/'})
-		if e.Space != "" {
-			w.WriteString(e.Space)
-			w.WriteByte(':')
-		}
-		w.WriteString(e.Tag)
+		w.WriteString(e.FullTag())
 		w.WriteByte('>')
 	} else {
 		if s.CanonicalEndTags {
 			w.Write([]byte{'>', '<', '/'})
-			if e.Space != "" {
-				w.WriteString(e.Space)
-				w.WriteByte(':')
-			}
-			w.WriteString(e.Tag)
+			w.WriteString(e.FullTag())
 			w.WriteByte('>')
 		} else {
 			w.Write([]byte{'/', '>'})
@@ -1094,6 +1091,15 @@ func (a byAttr) Less(i, j int) bool {
 	return sp < 0
 }
 
+// FullKey returns the attribute a's complete key, including namespace prefix
+// if present.
+func (a *Attr) FullKey() string {
+	if a.Space == "" {
+		return a.Key
+	}
+	return a.Space + ":" + a.Key
+}
+
 // Element returns the element containing the attribute.
 func (a *Attr) Element() *Element {
 	return a.element
@@ -1101,18 +1107,14 @@ func (a *Attr) Element() *Element {
 
 // NamespaceURI returns the XML namespace URI associated with the attribute.
 // If the element is part of the XML default namespace, NamespaceURI returns
-// empty string.
+// the empty string.
 func (a *Attr) NamespaceURI() string {
 	return a.element.NamespaceURI()
 }
 
 // writeTo serializes the attribute to the writer.
 func (a *Attr) writeTo(w *bufio.Writer, s *WriteSettings) {
-	if a.Space != "" {
-		w.WriteString(a.Space)
-		w.WriteByte(':')
-	}
-	w.WriteString(a.Key)
+	w.WriteString(a.FullKey())
 	w.WriteString(`="`)
 	var m escapeMode
 	if s.CanonicalAttrVal {