feed dump

src/feed/feed.go

@@ -0,0 +1,53 @@
+package feed
+
+import (
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+)
+
+var UnknownFormat = errors.New("unknown feed format")
+
+type processor func(r io.Reader) (*Feed, error)
+
+func detect(lookup string) (string, processor) {
+	lookup = strings.TrimSpace(lookup)
+	if lookup[0] == '{' {
+		return "json", ParseJSON
+	}
+	decoder := xml.NewDecoder(strings.NewReader(lookup))	
+	for {
+		token, _ := decoder.Token()
+		if token == nil {
+			break
+		}
+		if el, ok := token.(xml.StartElement); ok {
+			switch el.Name.Local {
+			case "rss":
+				return "rss", ParseRSS
+			case "RDF":
+				return "rss", ParseRDF
+			case "feed":
+				return "atom", ParseAtom
+			}
+		}
+	}
+	return "", nil
+}
+
+func Parse(r io.Reader) (*Feed, error) {
+	var x [1024]byte
+	numread, err := r.Read(x[:])
+	fmt.Println(numread, err)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to read: %s", err)
+	}
+
+	_, callback := detect(string(x[:]))
+	if callback == nil {
+		return nil, UnknownFormat
+	}
+	return callback(r)
+}