encoding.go

@@ -19,6 +19,9 @@ type MIMEVersion string
 // MIMEType represents the MIME type for the mail
 type MIMEType string
 
+// Disposition represents a content disposition for the Msg
+type Disposition string
+
 // List of supported encodings
 const (
 	// EncodingB64 represents the Base64 encoding as specified in RFC 2045.
@@ -160,6 +163,11 @@ const (
 	MIMESMime       MIMEType = `signed; protocol="application/pkcs7-signature"; micalg=sha256`
 )
 
+// List of common content disposition
+const (
+	DispositionSMime Disposition = `attachment; filename="smime.p7s"`
+)
+
 // String is a standard method to convert an Charset into a printable format
 func (c Charset) String() string {
 	return string(c)
@@ -174,3 +182,8 @@ func (c ContentType) String() string {
 func (e Encoding) String() string {
 	return string(e)
 }
+
+// String is a standard method to convert an Disposition into a printable format
+func (d Disposition) String() string {
+	return string(d)
+}

encoding_test.go

@@ -126,3 +126,22 @@ func TestCharset_String(t *testing.T) {
 		})
 	}
 }
+
+// TestDisposition_String tests the string method of the Disposition object
+func TestDisposition_String(t *testing.T) {
+	tests := []struct {
+		name string
+		d    Disposition
+		want string
+	}{
+		{"Disposition: S/Mime", DispositionSMime, `attachment; filename="smime.p7s"`},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.d.String() != tt.want {
+				t.Errorf("wrong string for Disposition returned. Expected: %s, got: %s",
+					tt.want, tt.d.String())
+			}
+		})
+	}
+}

msgwriter.go

@@ -269,6 +269,9 @@ func (mw *msgWriter) writePart(part *Part, charset Charset) {
 		if part.description != "" {
 			mimeHeader.Add(string(HeaderContentDescription), part.description)
 		}
+		if part.disposition != "" {
+			mimeHeader.Add(string(HeaderContentDisposition), part.disposition.String())
+		}
 		mimeHeader.Add(string(HeaderContentType), contentType)
 		mimeHeader.Add(string(HeaderContentTransferEnc), contentTransferEnc)
 		mw.newPart(mimeHeader)

part.go

@@ -17,10 +17,10 @@ type Part struct {
 	contentType ContentType
 	charset     Charset
 	description string
+	disposition Disposition
 	encoding    Encoding
 	isDeleted   bool
 	writeFunc   func(io.Writer) (int64, error)
-	smime       bool
 }
 
 // GetContent executes the WriteFunc of the Part and returns the content as byte slice
@@ -57,9 +57,9 @@ func (p *Part) GetDescription() string {
 	return p.description
 }
 
-// IsSMimeSigned returns true if the Part should be singed with S/MIME
+// GetDisposition returns the currently set Content-Disposition of the Part
-func (p *Part) IsSMimeSigned() bool {
+func (p *Part) GetDisposition() Disposition {
-	return p.smime
+	return p.disposition
 }
 
 // SetContent overrides the content of the Part with the given string
@@ -88,9 +88,9 @@ func (p *Part) SetDescription(description string) {
 	p.description = description
 }
 
-// SetIsSMimeSigned sets the flag for signing the Part with S/MIME
+// SetDisposition overrides the Content-Disposition of the Part
-func (p *Part) SetIsSMimeSigned(smime bool) {
+func (p *Part) SetDisposition(disposition Disposition) {
-	p.smime = smime
+	p.disposition = disposition
 }
 
 // SetWriteFunc overrides the WriteFunc of the Part
@@ -125,9 +125,9 @@ func WithPartContentDescription(description string) PartOption {
 	}
 }
 
-// WithSMimeSinging overrides the flag for signing the Part with S/MIME
+// WithContentDisposition overrides the default Part Content-Disposition
-func WithSMimeSinging() PartOption {
+func WithContentDisposition(disposition Disposition) PartOption {
 	return func(p *Part) {
-		p.smime = true
+		p.disposition = disposition
 	}
 }

part_test.go

@@ -102,21 +102,32 @@ func TestPart_WithPartContentDescription(t *testing.T) {
 	}
 }
 
-// TestPart_WithSMimeSinging tests the WithSMimeSinging method
+// TestPart_withContentDisposition tests the WithContentDisposition method
-func TestPart_WithSMimeSinging(t *testing.T) {
+func TestPart_withContentDisposition(t *testing.T) {
+	tests := []struct {
+		name        string
+		disposition Disposition
+	}{
+		{"Part disposition: test", "test"},
+		{"Part disposition: empty", ""},
+	}
+	for _, tt := range tests {
 		m := NewMsg()
-	part := m.newPart(TypeTextPlain, WithSMimeSinging())
+		t.Run(tt.name, func(t *testing.T) {
+			part := m.newPart(TypeTextPlain, WithContentDisposition(tt.disposition), nil)
 			if part == nil {
-		t.Errorf("newPart() WithSMimeSinging() failed: no part returned")
+				t.Errorf("newPart() WithPartContentDescription() failed: no part returned")
 				return
 			}
-	if part.smime != true {
+			if part.disposition != tt.disposition {
-		t.Errorf("newPart() WithSMimeSinging() failed: expected: %v, got: %v", true, part.smime)
+				t.Errorf("newPart() WithContentDisposition() failed: expected: %s, got: %s", tt.disposition, part.description)
 			}
-	part.smime = true
+			part.disposition = ""
-	part.SetIsSMimeSigned(false)
+			part.SetDisposition(tt.disposition)
-	if part.smime != false {
+			if part.disposition != tt.disposition {
-		t.Errorf("newPart() SetIsSMimeSigned() failed: expected: %v, got: %v", false, part.smime)
+				t.Errorf("newPart() SetDisposition() failed: expected: %s, got: %s", tt.disposition, part.description)
+			}
+		})
 	}
 }
 
@@ -263,32 +274,6 @@ func TestPart_GetContentBroken(t *testing.T) {
 	}
 }
 
-// TestPart_IsSMimeSigned tests Part.IsSMimeSigned
-func TestPart_IsSMimeSigned(t *testing.T) {
-	tests := []struct {
-		name string
-		want bool
-	}{
-		{"smime:", true},
-		{"smime:", false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			m := NewMsg()
-			pl, err := getPartList(m)
-			if err != nil {
-				t.Errorf("failed: %s", err)
-				return
-			}
-			pl[0].SetIsSMimeSigned(tt.want)
-			smime := pl[0].IsSMimeSigned()
-			if smime != tt.want {
-				t.Errorf("SetContentType failed. Got: %v, expected: %v", smime, tt.want)
-			}
-		})
-	}
-}
-
 // TestPart_SetWriteFunc tests Part.SetWriteFunc
 func TestPart_SetWriteFunc(t *testing.T) {
 	c := "This is a test with ümläutß"
@@ -367,6 +352,31 @@ func TestPart_SetDescription(t *testing.T) {
 	}
 }
 
+// TestPart_SetDisposition tests Part.SetDisposition
+func TestPart_SetDisposition(t *testing.T) {
+	c := "This is a test"
+	d := Disposition("test-disposition")
+	m := NewMsg()
+	m.SetBodyString(TypeTextPlain, c)
+	pl, err := getPartList(m)
+	if err != nil {
+		t.Errorf("failed: %s", err)
+		return
+	}
+	pd := pl[0].GetDisposition()
+	if pd != "" {
+		t.Errorf("Part.GetDisposition failed. Expected empty description but got: %s", pd)
+	}
+	pl[0].SetDisposition(d)
+	if pl[0].disposition != d {
+		t.Errorf("Part.SetDisposition failed. Expected description to be: %s, got: %s", d, pd)
+	}
+	pd = pl[0].GetDisposition()
+	if pd != d {
+		t.Errorf("Part.GetDisposition failed. Expected: %s, got: %s", d, pd)
+	}
+}
+
 // TestPart_Delete tests Part.Delete
 func TestPart_Delete(t *testing.T) {
 	c := "This is a test with ümläutß"