Implement easy to use method for outputting various oscal formats

types/oscal/oscal.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"encoding/xml"
 	"errors"
+	"fmt"
 	"io"
 	"io/ioutil"
 
@@ -217,6 +218,19 @@ func (o *OSCAL) YAML(w io.Writer) error {
 	return o.encode(encodeOptions{format: "yaml", writer: w})
 }
 
+// Write marshals OSCAL object as xml, json, or yaml
+func (o *OSCAL) Write(w io.Writer, format constants.DocumentFormat, prettify bool) error {
+	switch format {
+	case constants.XmlFormat:
+		return o.XML(w, prettify)
+	case constants.JsonFormat:
+		return o.JSON(w, prettify)
+	case constants.YamlFormat:
+		return o.YAML(w)
+	}
+	return fmt.Errorf("Unrecognized document format requested: %s", format.String())
+}
+
 type encodeOptions struct {
 	format   string
 	prettify bool