Move AbsURL into seperate file

1 files changed, 59 insertions, 0 deletions

diff --git a/transform/absurl.go b/transform/absurl.go
new file mode 100644
index 000000000..6e7eb125b
--- /dev/null
+++ b/transform/absurl.go
@@ -0,0 +1,59 @@
+package transform
+
+import (
+	htmltran "code.google.com/p/go-html-transform/html/transform"
+	"io"
+	"net/url"
+)
+
+type AbsURL struct {
+	BaseURL string
+}
+
+func (t *AbsURL) Apply(r io.Reader, w io.Writer) (err error) {
+	var tr *htmltran.Transformer
+
+	if tr, err = htmltran.NewFromReader(r); err != nil {
+		return
+	}
+
+	if err = t.absUrlify(tr, elattr{"a", "href"}, elattr{"script", "src"}); err != nil {
+		return
+	}
+
+	return tr.Render(w)
+}
+
+type elattr struct {
+	tag, attr string
+}
+
+func (t *AbsURL) absUrlify(tr *htmltran.Transformer, selectors ...elattr) (err error) {
+	var baseURL, inURL *url.URL
+
+	if baseURL, err = url.Parse(t.BaseURL); err != nil {
+		return
+	}
+
+	replace := func(in string) string {
+		if inURL, err = url.Parse(in); err != nil {
+			return in + "?"
+		}
+		if fragmentOnly(inURL) {
+			return in
+		}
+		return baseURL.ResolveReference(inURL).String()
+	}
+
+	for _, el := range selectors {
+		if err = tr.Apply(htmltran.TransformAttrib(el.attr, replace), el.tag); err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+func fragmentOnly(u *url.URL) bool {
+	return u.Fragment != "" && u.Scheme == "" && u.Opaque == "" && u.User == nil && u.Host == "" && u.Path == "" && u.Path == "" && u.RawQuery == ""
+}