Added more error handling and necessary functions

generator.go

@@ -2,6 +2,7 @@ package atom
 
 import (
 	"encoding/xml"
+	"errors"
 	"fmt"
 	"html"
 )
@@ -9,14 +10,27 @@ import (
 type Generator struct {
 	XMLName xml.Name `xml:"generator"`
 	*CommonAttributes
-	URI     IRI    `xml:"uri,attr,omitempty"`
+	URI     string `xml:"uri,attr,omitempty"` // IRI
 	Version string `xml:"version,attr,omitempty"`
 	Text    string `xml:",chardata"`
 }
 
-// NewGenerator creates a new Generator. It returns a *Generator.
-func NewGenerator(text string) *Generator {
-	return &Generator{Text: html.UnescapeString(text)}
+// NewGenerator creates a new Generator. It returns a *Generator and an error.
+func NewGenerator(text string) (*Generator, error) {
+	if text == "" {
+		return nil, errors.New("error creating new generator: text string empty")
+	}
+
+	return &Generator{Text: html.UnescapeString(text)}, nil
+}
+
+// SetURI sets the URI attribute of the Generator. It returns an error.
+func (g *Generator) SetURI(uri string) error {
+	if !isValidIRI(uri) {
+		return fmt.Errorf("uri %v not correctly formatted", g)
+	}
+
+	return nil
 }
 
 // Check checks the Generator for incompatibilities with RFC4287. It returns an