Added more error handling and necessary functions

outOfLineContent.go

@@ -9,18 +9,19 @@ import (
 type OutOfLineContent struct {
 	XMLName xml.Name `xml:"content"`
 	*CommonAttributes
-	Type MediaType `xml:"type,attr,omitempty"`
-	SRC  IRI       `xml:"src,attr"`
+	Type string `xml:"type,attr,omitempty"` // MediaType
+	SRC  string `xml:"src,attr"`            // IRI
 }
 
 // newOutOfLineContent creates a new OutOfLineContent. It returns a
 // *OutOfLineContent and an error.
 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 !isValidMediaType(mediaType) {
+		return nil, fmt.Errorf("error creating new out of line content: media type %v invalid", mediaType)
 	}
+	mediaType, _, _ = mime.ParseMediaType(mediaType)
 
-	iri, ok := content.(IRI)
+	iri, ok := content.(string)
 	if !ok {
 		return nil, fmt.Errorf("content type %T incompatible with out of line content", content)
 	}
@@ -29,7 +30,7 @@ func newOutOfLineContent(mediaType string, content any) (*OutOfLineContent, erro
 		return nil, fmt.Errorf("content %v not a valid uri", iri)
 	}
 
-	return &OutOfLineContent{Type: MediaType(mediaType), SRC: iri}, nil
+	return &OutOfLineContent{Type: mediaType, SRC: iri}, nil
 }
 
 // isContent checks whether the OutOfLineContent is a Content. It returns a
@@ -41,15 +42,15 @@ func (o *OutOfLineContent) isContent() bool { return true }
 func (o *OutOfLineContent) hasSRC() bool { return true }
 
 // getType returns the Type of the OutOfLineContent as a string.
-func (o *OutOfLineContent) getType() string { return string(o.Type) }
+func (o *OutOfLineContent) getType() string { return o.Type }
 
 // Check checks the OutOfLineContent for incompatibilities with RFC4287. It
 // returns an error.
 func (o *OutOfLineContent) Check() error {
 	mediaType := o.getType()
 
-	if mediaType, _, err := mime.ParseMediaType(mediaType); err != nil {
-		return fmt.Errorf("type attribute %v incompatible with out of line content", mediaType)
+	if !isValidMediaType(mediaType) {
+		return fmt.Errorf("type attribute of out of line content %v invalid media type", o)
 	}
 
 	if isCompositeMediaType(mediaType) {