v0.2.0

ADDED:
* The ability to show both IPv4 and IPv6 addresses (if the client has
  dual-stack and either the server does as well or a separate ClientInfo
  is running on the "other" net family).

server/funcs_page.go

@@ -4,6 +4,48 @@ import (
 	`fmt`
 )
 
+func (p *Page) AltURL() (altUrl string) {
+
+	if !p.HasAltURL() {
+		return
+	}
+
+	if p.Info.IP.Is4() {
+		altUrl = p.srv.v6Url.String()
+	} else if p.Info.IP.Is6() {
+		altUrl = p.srv.v4Url.String()
+	}
+
+	return
+}
+
+func (p *Page) AltVer() (altVer string) {
+
+	if !p.HasAltURL() {
+		return
+	}
+
+	if p.Info.IP.Is4() {
+		altVer = "v6"
+	} else if p.Info.IP.Is6() {
+		altVer = "v4"
+	}
+
+	return
+}
+
+func (p *Page) HasAltURL() (hasAlt bool) {
+
+	if p.Info == nil {
+		return
+	}
+
+	hasAlt = (p.Info.IP.Is4() && p.srv.v6Url != nil) ||
+		(p.Info.IP.Is6() && p.srv.v4Url != nil)
+
+	return
+}
+
 func (p *Page) RenderIP(indent uint) (s string) {
 
 	s = fmt.Sprintf("<a href=\"https://ipinfo.io/%s\">%s</a>", p.Info.IP.String(), p.Info.IP.String())