Add basic builder support

stanza/builder.go

@@ -0,0 +1,62 @@
+package stanza
+
+import (
+	"encoding/xml"
+)
+
+type builder struct{ lang string }
+
+// NewBuilder create a builder structure. It act as an interface for packet generation.
+// The goal is to work well with code completion to more easily.
+//
+// Using the builder to format and create packets is optional. You can always prepare
+// your packet dealing with the struct manually and initializing them with the right values.
+func NewBuilder() *builder {
+	return &builder{}
+}
+
+// Set default language
+func (b *builder) Lang(lang string) *builder {
+	b.lang = lang
+	return b
+}
+
+func (b *builder) IQ(a Attrs) IQ {
+	return IQ{
+		XMLName: xml.Name{Local: "iq"},
+		Attrs:   a,
+	}
+}
+
+func (b *builder) Message(a Attrs) Message {
+	return Message{
+		XMLName: xml.Name{Local: "message"},
+		Attrs:   a,
+	}
+}
+
+func (b *builder) Presence(a Attrs) Presence {
+	return Presence{
+		XMLName: xml.Name{Local: "presence"},
+		Attrs:   a,
+	}
+}
+
+// ======================================================================================
+// IQ payloads
+
+// DiscoInfo builds a default DiscoInfo payload
+func (*builder) DiscoInfo() *DiscoInfo {
+	d := DiscoInfo{
+		XMLName: xml.Name{
+			Space: NSDiscoInfo,
+			Local: "query",
+		},
+	}
+	return &d
+}
+
+// Identity builds a identity struct for use in Disco
+func (*builder) Identity(name, category, typ string) *Identity {
+	return &Identity{}
+}