Add newOutOfLineContent

outOfLineContent.go

@@ -1,6 +1,12 @@
 package atomfeed
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+	"mime"
+	"net/url"
+	"reflect"
+)
 
 type OutOfLineContent struct {
 	*CommonAttributes
@@ -8,6 +14,22 @@ type OutOfLineContent struct {
 	SRC  URI       `xml:"src,attr"`
 }
 
+func newOutOfLineContent(mediaType string, content any) (*OutOfLineContent, error) {
+	if mediaType, _, err := mime.ParseMediaType(mediaType); err != nil {
+		return nil, fmt.Errorf("media type %v incompatible with out of line content", mediaType)
+	}
+
+	if reflect.TypeOf(content).Kind() != reflect.String {
+		return nil, fmt.Errorf("content type %T incompatible with out of line content", content)
+	}
+
+	if _, err := url.ParseRequestURI(content.(string)); err != nil {
+		return nil, errors.New("content not a valid uri")
+	}
+
+	return &OutOfLineContent{Type: MediaType(mediaType), SRC: content.(URI)}, nil
+}
+
 func (o *OutOfLineContent) isContent() bool { return true }
 
 func (o *OutOfLineContent) hasSRC() bool { return true }