Use built-in xml attributes

README.md

@@ -1,4 +1,3 @@
-# atom-feed
+# atom
 
 An extensible implementation of an Atom feed that aims to be very close to RFC4287.
-

atom.go

@@ -82,6 +82,12 @@ func isValidLanguageTag(tag LanguageTag) bool {
 	return err == nil
 }
 
+// isValidAttribute checks whether an Attribute is valid. It returns a bool.
+func isValidAttribute(attribute string) bool {
+	regex := regexp.MustCompile(`^[a-zA-Z0-9_]+="[^"]*"$`)
+	return regex.MatchString(attribute)
+}
+
 // NewURN generates an new valid IRI based on a UUID. It returns an IRI.
 func NewURN() IRI {
 	return IRI(fmt.Sprint("urn:uuid:", uuid.New()))

commonAttributes.go

@@ -1,21 +1,27 @@
 package atom
 
-import "fmt"
+import (
+	"encoding/xml"
+)
 
 type CommonAttributes struct {
 	Base                IRI         `xml:"base,attr,omitempty"`
 	Lang                LanguageTag `xml:"lang,attr,omitempty"`
-	UndefinedAttributes []*ExtensionAttribute `xml:",any"`
+	UndefinedAttributes []*xml.Attr `xml:",attr,omitempty"`
 }
 
-// Check checks the CommonAttributes for incompatibilities with RFC4287. It
-// returns an error.
-func (c *CommonAttributes) Check() error {
-	for i, e := range c.UndefinedAttributes {
-		if err := e.Check(); err != nil {
-			return fmt.Errorf("extension attribute %v of common attributes: %v", i, err)
-		}
+// NewCommonAttributes creates a new set of CommonAttributes. It returns a
+// *CommonAttributes.
+func NewCommonAttributes() *CommonAttributes {
+	return new(CommonAttributes)
 }
 
-	return nil
+// AddExtensionAttribute adds the ExtensionAttribute to the CommonAttributes.
+func (c *CommonAttributes) AddExtensionAttribute(name, value string) {
+	if c.UndefinedAttributes == nil {
+		c.UndefinedAttributes = make([]*xml.Attr, 1)
+		c.UndefinedAttributes[0] = &xml.Attr{Name: xml.Name{Local: name}, Value: value}
+	} else {
+		c.UndefinedAttributes = append(c.UndefinedAttributes, &xml.Attr{Name: xml.Name{Local: name}, Value: value})
+	}
 }

extensionAttribute.go

@@ -1,22 +0,0 @@
-package atom
-
-import (
-	"encoding/xml"
-	"errors"
-)
-
-// TODO: Is this really correct?
-type ExtensionAttribute struct {
-	Value   any `xml:",attr"`
-	XMLName xml.Name
-}
-
-// Check checks the ExtensionAttribute for incompatibilities with RFC4287. It
-// returns an error.
-func (e *ExtensionAttribute) Check() error {
-	if e.Value == nil {
-		return errors.New("value element of extension attribute empty")
-	}
-
-	return nil
-}

extensionElement.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 )
 
-// TODO: Is this really correct?
 type ExtensionElement struct {
 	Value   any `xml:",innerxml"`
 	XMLName xml.Name