Get rid of checks when creating constructs. Check should handle this.

commonAttributes.go

@@ -2,7 +2,7 @@ package atom
 
 import (
 	"encoding/xml"
-	"errors"
+	"fmt"
 )
 
 type CommonAttributes struct {
@@ -17,21 +17,27 @@ func NewCommonAttributes() *CommonAttributes {
 	return new(CommonAttributes)
 }
 
-// AddAttribute adds the Attribute to the CommonAttributes. It returns an error.
-func (c *CommonAttributes) AddAttribute(name, value string) error {
-	if name == "" {
-		return errors.New("error adding attribute: name string empty")
-	}
-	if value == "" {
-		return errors.New("error adding attribute: value string empty")
-	}
-
+// AddAttribute adds the Attribute to the CommonAttributes.
+func (c *CommonAttributes) AddAttribute(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})
 	}
+}
+
+// Check checks the CommonAttributes for incompatibilities with RFC4287. It
+// returns an error.
+func (c *CommonAttributes) Check() error {
+	for i, u := range c.UndefinedAttributes {
+		if u.Name.Local == "" {
+			return fmt.Errorf("xml name of undefined attribute %v empty", i)
+		}
+		if u.Value == "" {
+			return fmt.Errorf("value of undefined attribute %v empty", i)
+		}
+	}
 
 	return nil
 }