Adds optional indented output for the Node.String() and Node.Bytes()

methods. Set the global `IndentPrefix` var to a tab or spaces to
enable indented output. The existing API has not been changed.

This addresses issue #7.

Author: jimt

document.go

@@ -29,7 +29,6 @@ package xmlx
 
 import (
 	"bytes"
-	//"code.google.com/p/go-charset/charset"
 	"encoding/xml"
 	"errors"
 	"fmt"
@@ -206,6 +205,10 @@ func (this *Document) SaveBytes() []byte {
 	if this.SaveDocType {
 		b.WriteString(fmt.Sprintf(`<?xml version="%s" encoding="%s" standalone="%s"?>`,
 			this.Version, this.Encoding, this.StandAlone))
+
+		if len(IndentPrefix) > 0 {
+			b.WriteByte('\n')
+		}
 	}
 
 	b.Write(this.Root.Bytes())

node.go

@@ -9,6 +9,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"strconv"
+	"strings"
 )
 
 const (
@@ -19,6 +20,11 @@ const (
 	NT_ELEMENT
 )
 
+// IndentPrefix holds the value for a single identation level, if one
+// chooses to want indentation in the node.String() and node.Bytes() output.
+// This would normally be set to a single tab, or a number of spaces.
+var IndentPrefix = ""
+
 type Attr struct {
 	Name  xml.Name // Attribute namespace and name.
 	Value string   // Attribute value. 
@@ -45,7 +51,7 @@ func NewNode(tid byte) *Node {
 // This wraps the standard xml.Unmarshal function and supplies this particular
 // node as the content to be unmarshalled.
 func (this *Node) Unmarshal(obj interface{}) error {
-	return xml.NewDecoder(bytes.NewBuffer(this.Bytes())).Decode(obj)
+	return xml.NewDecoder(bytes.NewBuffer(this.bytes(0))).Decode(obj)
 }
 
 // Get node value as string
@@ -258,18 +264,20 @@ func rec_SelectNodes(cn *Node, namespace, name string, list *[]*Node, recurse bo
 // Note that NT_ROOT is a special-case empty node used as the root for a
 // Document. This one has no representation by itself. It merely forwards the
 // String() call to it's child nodes.
-func (this *Node) Bytes() (b []byte) {
+func (this *Node) Bytes() []byte { return this.bytes(0) }
+
+func (this *Node) bytes(indent int) (b []byte) {
 	switch this.Type {
 	case NT_PROCINST:
-		b = this.printProcInst()
+		b = this.printProcInst(indent)
 	case NT_COMMENT:
-		b = this.printComment()
+		b = this.printComment(indent)
 	case NT_DIRECTIVE:
-		b = this.printDirective()
+		b = this.printDirective(indent)
 	case NT_ELEMENT:
-		b = this.printElement()
+		b = this.printElement(indent)
 	case NT_ROOT:
-		b = this.printRoot()
+		b = this.printRoot(indent)
 	}
 	return
 }
@@ -279,32 +287,38 @@ func (this *Node) Bytes() (b []byte) {
 // Document. This one has no representation by itself. It merely forwards the
 // String() call to it's child nodes.
 func (this *Node) String() (s string) {
-	return string(this.Bytes())
+	return string(this.bytes(0))
 }
 
-func (this *Node) printRoot() []byte {
+func (this *Node) printRoot(indent int) []byte {
 	var b bytes.Buffer
 	for _, v := range this.Children {
-		b.Write(v.Bytes())
+		b.Write(v.bytes(indent))
 	}
 	return b.Bytes()
 }
 
-func (this *Node) printProcInst() []byte {
+func (this *Node) printProcInst(indent int) []byte {
 	return []byte("<?" + this.Target + " " + this.Value + "?>")
 }
 
-func (this *Node) printComment() []byte {
+func (this *Node) printComment(indent int) []byte {
 	return []byte("<!-- " + this.Value + " -->")
 }
 
-func (this *Node) printDirective() []byte {
+func (this *Node) printDirective(indent int) []byte {
 	return []byte("<!" + this.Value + "!>")
 }
 
-func (this *Node) printElement() []byte {
+func (this *Node) printElement(indent int) []byte {
 	var b bytes.Buffer
 
+	lineSuffix, linePrefix := "", strings.Repeat(IndentPrefix, indent)
+	if len(IndentPrefix) > 0 {
+		lineSuffix = "\n"
+	}
+
+	b.WriteString(linePrefix)
 	if len(this.Name.Space) > 0 {
 		b.WriteRune('<')
 		b.WriteString(this.Name.Space)
@@ -325,16 +339,23 @@ func (this *Node) printElement() []byte {
 
 	if len(this.Children) == 0 && len(this.Value) == 0 {
 		b.WriteString(" />")
+		b.WriteString(lineSuffix)
 		return b.Bytes()
 	}
 
 	b.WriteRune('>')
+	if len(this.Value) == 0 {
+		b.WriteString(lineSuffix)
+	}
 
 	for _, v := range this.Children {
-		b.Write(v.Bytes())
+		b.Write(v.bytes(indent + 1))
 	}
 
 	b.WriteString(this.Value)
+	if len(this.Value) == 0 {
+		b.WriteString(linePrefix)
+	}
 	if len(this.Name.Space) > 0 {
 		b.WriteString("</")
 		b.WriteString(this.Name.Space)
@@ -346,6 +367,7 @@ func (this *Node) printElement() []byte {
 		b.WriteString(this.Name.Local)
 		b.WriteRune('>')
 	}
+	b.WriteString(lineSuffix)
 
 	return b.Bytes()
 }

test1.xml

@@ -1 +1,50 @@
-<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="0.91"><channel><title>WriteTheWeb</title><link>http://writetheweb.com</link><description>News for web users that write back</description><language>en-us</language><copyright>Copyright 2000, WriteTheWeb team.</copyright><managingEditor>editor@writetheweb.com</managingEditor><webMaster>webmaster@writetheweb.com</webMaster><image><title>WriteTheWeb</title><url>http://writetheweb.com/images/mynetscape88.gif</url><link>http://writetheweb.com</link><width>88</width><height>31</height><description>News for web users that write back</description></image><item><title>Giving the world a pluggable Gnutella</title><link>http://writetheweb.com/read.php?item=24</link><description>WorldOS is a framework on which to build programs that work like Freenet or Gnutella -allowing distributed applications using peer-to-peer routing.</description></item><item><title>Syndication discussions hot up</title><link>http://writetheweb.com/read.php?item=23</link><description>After a period of dormancy, the Syndication mailing list has become active again, with contributions from leaders in traditional media and Web syndication.</description></item><item><title>Personal web server integrates file sharing and messaging</title><link>http://writetheweb.com/read.php?item=22</link><description>The Magi Project is an innovative project to create a combined personal web server and messaging system that enables the sharing and synchronization of information across desktop, laptop and palmtop devices.</description></item><item><title>Syndication and Metadata</title><link>http://writetheweb.com/read.php?item=21</link><description>RSS is probably the best known metadata format around. RDF is probably one of the least understood. In this essay, published on my O'Reilly Network weblog, I argue that the next generation of RSS should be based on RDF.</description></item><item><title>UK bloggers get organised</title><link>http://writetheweb.com/read.php?item=20</link><description>Looks like the weblogs scene is gathering pace beyond the shores of the US. There's now a UK-specific page on weblogs.com, and a mailing list at egroups.</description></item><item><title>Yournamehere.com more important than anything</title><link>http://writetheweb.com/read.php?item=19</link><description>Whatever you're publishing on the web, your site name is the most valuable asset you have, according to Carl Steadman.</description></item></channel></rss>
+<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+<rss version="0.91">
+	<channel>
+		<title>WriteTheWeb</title>
+		<link>http://writetheweb.com</link>
+		<description>News for web users that write back</description>
+		<language>en-us</language>
+		<copyright>Copyright 2000, WriteTheWeb team.</copyright>
+		<managingEditor>editor@writetheweb.com</managingEditor>
+		<webMaster>webmaster@writetheweb.com</webMaster>
+		<image>
+			<title>WriteTheWeb</title>
+			<url>http://writetheweb.com/images/mynetscape88.gif</url>
+			<link>http://writetheweb.com</link>
+			<width>88</width>
+			<height>31</height>
+			<description>News for web users that write back</description>
+		</image>
+		<item>
+			<title>Giving the world a pluggable Gnutella</title>
+			<link>http://writetheweb.com/read.php?item=24</link>
+			<description>WorldOS is a framework on which to build programs that work like Freenet or Gnutella -allowing distributed applications using peer-to-peer routing.</description>
+		</item>
+		<item>
+			<title>Syndication discussions hot up</title>
+			<link>http://writetheweb.com/read.php?item=23</link>
+			<description>After a period of dormancy, the Syndication mailing list has become active again, with contributions from leaders in traditional media and Web syndication.</description>
+		</item>
+		<item>
+			<title>Personal web server integrates file sharing and messaging</title>
+			<link>http://writetheweb.com/read.php?item=22</link>
+			<description>The Magi Project is an innovative project to create a combined personal web server and messaging system that enables the sharing and synchronization of information across desktop, laptop and palmtop devices.</description>
+		</item>
+		<item>
+			<title>Syndication and Metadata</title>
+			<link>http://writetheweb.com/read.php?item=21</link>
+			<description>RSS is probably the best known metadata format around. RDF is probably one of the least understood. In this essay, published on my O'Reilly Network weblog, I argue that the next generation of RSS should be based on RDF.</description>
+		</item>
+		<item>
+			<title>UK bloggers get organised</title>
+			<link>http://writetheweb.com/read.php?item=20</link>
+			<description>Looks like the weblogs scene is gathering pace beyond the shores of the US. There's now a UK-specific page on weblogs.com, and a mailing list at egroups.</description>
+		</item>
+		<item>
+			<title>Yournamehere.com more important than anything</title>
+			<link>http://writetheweb.com/read.php?item=19</link>
+			<description>Whatever you're publishing on the web, your site name is the most valuable asset you have, according to Carl Steadman.</description>
+		</item>
+	</channel>
+</rss>

xmlx_test.go

@@ -74,6 +74,7 @@ func TestSave(t *testing.T) {
 		return
 	}
 
+	IndentPrefix = "\t"
 	if err := doc.SaveFile("test1.xml"); err != nil {
 		t.Errorf("SaveFile(): %s", err)
 		return