Add source_field for media events

pkg/api/events.go

@@ -65,6 +65,7 @@ type Content struct {
 	DestinationMimeType string `json:"mimetype" description:"MIME type of the derivative being created"`
 	Args                string `json:"args" description:"Arguments used or applicable to the content"`
 	SourceURI           string `json:"source_uri" description:"Source URI from which the content is fetched"`
+	SourceField         string `json:"source_field" description:"Source field from which the media is fetched"`
 	DestinationURI      string `json:"destination_uri" description:"Destination URI to where the content is delivered"`
 	FileUploadURI       string `json:"file_upload_uri" description:"File upload URI for uploading the content"`
 }