// IsAttachment returns true, if the given header defines an attachment.
// First it checks, if the Content-Disposition header defines an attachement.
// If this test is false, the Content-Type header is checked.
//
// Valid Attachment-Headers:
//
// Content-Disposition: attachment; filename="frog.jpg"
// Content-Type: attachment; filename="frog.jpg"
//
func IsAttachment(header mail.Header) bool {
mediatype, _, _ := mime.ParseMediaType(header.Get("Content-Disposition"))
if strings.ToLower(mediatype) == "attachment" {
return true
}
mediatype, _, _ = mime.ParseMediaType(header.Get("Content-Type"))
if strings.ToLower(mediatype) == "attachment" {
return true
}
return false
}
// IsPlain returns true, if the the mime headers define a valid
// 'text/plain' or 'text/html part'. Ff emptyContentTypeIsPlain is set
// to true, a missing Content-Type header will result in a positive
// plain part detection.
func IsPlain(header mail.Header, emptyContentTypeIsPlain bool) bool {
ctype := header.Get("Content-Type")
if ctype == "" && emptyContentTypeIsPlain {
return true
}
mediatype, _, err := mime.ParseMediaType(ctype)
if err != nil {
return false
}
switch mediatype {
case "text/plain",
"text/html":
return true
}
return false
}