Add support for Atom 0.3

reader/atom/parser.go

@@ -5,21 +5,58 @@
 package atom // import "miniflux.app/reader/atom"
 
 import (
+	"bytes"
+	"encoding/xml"
 	"io"
 
 	"miniflux.app/errors"
 	"miniflux.app/model"
-	"miniflux.app/reader/xml"
+	xml_decoder "miniflux.app/reader/xml"
 )
 
+type atomFeed interface {
+	Transform() *model.Feed
+}
+
 // Parse returns a normalized feed struct from a Atom feed.
-func Parse(data io.Reader) (*model.Feed, *errors.LocalizedError) {
-	atomFeed := new(atomFeed)
-	decoder := xml.NewDecoder(data)
-	err := decoder.Decode(atomFeed)
+func Parse(r io.Reader) (*model.Feed, *errors.LocalizedError) {
+	var buf bytes.Buffer
+	tee := io.TeeReader(r, &buf)
+
+	var rawFeed atomFeed
+	if getAtomFeedVersion(tee) == "0.3" {
+		rawFeed = new(atom03Feed)
+	} else {
+		rawFeed = new(atom10Feed)
+	}
+
+	decoder := xml_decoder.NewDecoder(&buf)
+	err := decoder.Decode(rawFeed)
 	if err != nil {
 		return nil, errors.NewLocalizedError("Unable to parse Atom feed: %q", err)
 	}
 
-	return atomFeed.Transform(), nil
+	return rawFeed.Transform(), nil
+}
+
+func getAtomFeedVersion(data io.Reader) string {
+	decoder := xml_decoder.NewDecoder(data)
+	for {
+		token, _ := decoder.Token()
+		if token == nil {
+			break
+		}
+
+		if element, ok := token.(xml.StartElement); ok {
+			if element.Name.Local == "feed" {
+				for _, attr := range element.Attr {
+					if attr.Name.Local == "version" && attr.Value == "0.3" {
+						return "0.3"
+					}
+				}
+				return "1.0"
+			}
+		}
+	}
+	return "1.0"
 }