mirror of
https://github.com/wneessen/go-mail.git
synced 2024-11-24 22:50:49 +01:00
Add content type, charset processing and refactor encoding process
Extended the settings for content type and charset from headers. Also, refactored the handling of encoding types - 'QP' and 'B64' - within the mail header and body parsing sections. The process of handling encoding for plain type mail specifically is now encapsulated in a new function, parseEMLBodyPlain. These changes enhance code readability, maintainability, and error handling efficiency.
This commit is contained in:
parent
4202f705a0
commit
53566a93cd
1 changed files with 85 additions and 31 deletions
116
eml.go
116
eml.go
|
@ -111,6 +111,28 @@ func parseEMLHeaders(mh *nm.Header, m *Msg) error {
|
|||
HeaderXMailer, HeaderXMSMailPriority, HeaderXPriority,
|
||||
}
|
||||
|
||||
// Extract content type, charset and encoding first
|
||||
if v := mh.Get(HeaderContentTransferEnc.String()); v != "" {
|
||||
switch {
|
||||
case strings.EqualFold(v, EncodingQP.String()):
|
||||
m.SetEncoding(EncodingQP)
|
||||
case strings.EqualFold(v, EncodingB64.String()):
|
||||
m.SetEncoding(EncodingB64)
|
||||
default:
|
||||
m.SetEncoding(NoEncoding)
|
||||
}
|
||||
}
|
||||
if v := mh.Get(HeaderContentType.String()); v != "" {
|
||||
ct, cs := parseContentType(v)
|
||||
if cs != "" {
|
||||
m.SetCharset(Charset(cs))
|
||||
}
|
||||
m.setEncoder()
|
||||
if ct != "" {
|
||||
m.SetGenHeader(HeaderContentType, ct)
|
||||
}
|
||||
}
|
||||
|
||||
// Extract address headers
|
||||
if v := mh.Get(HeaderFrom.String()); v != "" {
|
||||
if err := m.From(v); err != nil {
|
||||
|
@ -156,6 +178,9 @@ func parseEMLHeaders(mh *nm.Header, m *Msg) error {
|
|||
for _, h := range commonHeaders {
|
||||
if v := mh.Get(h.String()); v != "" {
|
||||
m.SetGenHeader(h, v)
|
||||
if strings.EqualFold(h.String(), "subject") {
|
||||
fmt.Printf("SUBJECT: %s\n", m.GetGenHeader(HeaderSubject)[0])
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -173,43 +198,52 @@ func parseEMLBodyParts(pm *nm.Message, bodybuf *bytes.Buffer, m *Msg) error {
|
|||
m.SetCharset(Charset(v))
|
||||
}
|
||||
|
||||
cte := pm.Header.Get(HeaderContentTransferEnc.String())
|
||||
switch strings.ToLower(mediatype) {
|
||||
case TypeTextPlain.String():
|
||||
if strings.EqualFold(cte, NoEncoding.String()) {
|
||||
m.SetEncoding(NoEncoding)
|
||||
m.SetBodyString(TypeTextPlain, bodybuf.String())
|
||||
break
|
||||
switch {
|
||||
case strings.EqualFold(mediatype, TypeTextPlain.String()),
|
||||
strings.EqualFold(mediatype, TypeTextHTML.String()):
|
||||
if err := parseEMLBodyPlain(mediatype, pm, bodybuf, m); err != nil {
|
||||
return fmt.Errorf("failed to parse plain body: %w", err)
|
||||
}
|
||||
if strings.EqualFold(cte, EncodingQP.String()) {
|
||||
m.SetEncoding(EncodingQP)
|
||||
qpr := quotedprintable.NewReader(bodybuf)
|
||||
qpbuf := bytes.Buffer{}
|
||||
if _, err = qpbuf.ReadFrom(qpr); err != nil {
|
||||
return fmt.Errorf("failed to read quoted-printable body: %w", err)
|
||||
}
|
||||
m.SetBodyString(TypeTextPlain, qpbuf.String())
|
||||
break
|
||||
}
|
||||
if strings.EqualFold(cte, EncodingB64.String()) {
|
||||
m.SetEncoding(EncodingB64)
|
||||
b64d := base64.NewDecoder(base64.StdEncoding, bodybuf)
|
||||
b64buf := bytes.Buffer{}
|
||||
if _, err = b64buf.ReadFrom(b64d); err != nil {
|
||||
return fmt.Errorf("failed to read base64 body: %w", err)
|
||||
}
|
||||
m.SetBodyString(TypeTextPlain, b64buf.String())
|
||||
break
|
||||
}
|
||||
case TypeMultipartAlternative.String():
|
||||
case strings.EqualFold(mediatype, TypeMultipartAlternative.String()):
|
||||
if err := parseEMLMultipartAlternative(params, bodybuf, m); err != nil {
|
||||
return fmt.Errorf("failed to parse multipart/alternative: %w", err)
|
||||
return fmt.Errorf("failed to parse multipart/alternative body: %w", err)
|
||||
}
|
||||
default:
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// parseEMLBodyPlain parses the mail body of plain type mails
|
||||
func parseEMLBodyPlain(mediatype string, pm *nm.Message, bodybuf *bytes.Buffer, m *Msg) error {
|
||||
cte := pm.Header.Get(HeaderContentTransferEnc.String())
|
||||
if strings.EqualFold(cte, NoEncoding.String()) {
|
||||
m.SetEncoding(NoEncoding)
|
||||
m.SetBodyString(ContentType(mediatype), bodybuf.String())
|
||||
return nil
|
||||
}
|
||||
if strings.EqualFold(cte, EncodingQP.String()) {
|
||||
m.SetEncoding(EncodingQP)
|
||||
qpr := quotedprintable.NewReader(bodybuf)
|
||||
qpbuf := bytes.Buffer{}
|
||||
if _, err := qpbuf.ReadFrom(qpr); err != nil {
|
||||
return fmt.Errorf("failed to read quoted-printable body: %w", err)
|
||||
}
|
||||
m.SetBodyString(ContentType(mediatype), qpbuf.String())
|
||||
return nil
|
||||
}
|
||||
if strings.EqualFold(cte, EncodingB64.String()) {
|
||||
m.SetEncoding(EncodingB64)
|
||||
b64d := base64.NewDecoder(base64.StdEncoding, bodybuf)
|
||||
b64buf := bytes.Buffer{}
|
||||
if _, err := b64buf.ReadFrom(b64d); err != nil {
|
||||
return fmt.Errorf("failed to read base64 body: %w", err)
|
||||
}
|
||||
m.SetBodyString(ContentType(mediatype), b64buf.String())
|
||||
return nil
|
||||
}
|
||||
return fmt.Errorf("unsupported Content-Transfer-Encoding")
|
||||
}
|
||||
|
||||
// parseEMLMultipartAlternative parses a multipart/alternative body part of a EML
|
||||
func parseEMLMultipartAlternative(params map[string]string, bodybuf *bytes.Buffer, m *Msg) error {
|
||||
boundary, ok := params["boundary"]
|
||||
|
@ -242,7 +276,7 @@ func parseEMLMultipartAlternative(params map[string]string, bodybuf *bytes.Buffe
|
|||
}
|
||||
switch {
|
||||
case strings.EqualFold(mpTransferEnc[0], EncodingB64.String()):
|
||||
if err := handleEMLMultiPartBase64Encoding(mpTransferEnc, mpdata, p); err != nil {
|
||||
if err := handleEMLMultiPartBase64Encoding(mpdata, p); err != nil {
|
||||
return fmt.Errorf("failed to handle multipart base64 transfer-encoding: %w", err)
|
||||
}
|
||||
}
|
||||
|
@ -257,6 +291,8 @@ func parseEMLMultipartAlternative(params map[string]string, bodybuf *bytes.Buffe
|
|||
return nil
|
||||
}
|
||||
|
||||
// parseEMLMultiPartCharset parses the Charset from a ContentType header and assigns it to a Part
|
||||
// TODO: This might be redundant to parseContentType
|
||||
func parseEMLMultiPartCharset(mpContentTypeSplit []string, p *Part) {
|
||||
if len(mpContentTypeSplit) > 1 && strings.HasPrefix(strings.ToLower(mpContentTypeSplit[1]), "charset=") {
|
||||
valSplit := strings.Split(mpContentTypeSplit[1], "=")
|
||||
|
@ -266,7 +302,8 @@ func parseEMLMultiPartCharset(mpContentTypeSplit []string, p *Part) {
|
|||
}
|
||||
}
|
||||
|
||||
func handleEMLMultiPartBase64Encoding(mpTransferEnc []string, mpdata []byte, p *Part) error {
|
||||
// handleEMLMultiPartBase64Encoding sets the content body of a base64 encoded Part
|
||||
func handleEMLMultiPartBase64Encoding(mpdata []byte, p *Part) error {
|
||||
p.SetEncoding(EncodingB64)
|
||||
cont, err := base64.StdEncoding.DecodeString(string(mpdata))
|
||||
if err != nil {
|
||||
|
@ -275,3 +312,20 @@ func handleEMLMultiPartBase64Encoding(mpTransferEnc []string, mpdata []byte, p *
|
|||
p.SetContent(string(cont))
|
||||
return nil
|
||||
}
|
||||
|
||||
// parseContentType parses the Content-Type header and returns the type and charse as
|
||||
// separate string values
|
||||
func parseContentType(cth string) (ct string, cs string) {
|
||||
cts := strings.SplitN(cth, "; ", 2)
|
||||
if len(cts) != 2 {
|
||||
return
|
||||
}
|
||||
ct = cts[0]
|
||||
if strings.HasPrefix(strings.ToLower(cts[1]), "charset=") {
|
||||
css := strings.SplitN(cts[1], "=", 2)
|
||||
if len(css) == 2 {
|
||||
cs = css[1]
|
||||
}
|
||||
}
|
||||
return
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue