From 030f39043628f01b174ebb11595a4e74da95f0b3 Mon Sep 17 00:00:00 2001 From: Ben Burwell Date: Thu, 4 Jul 2019 11:01:07 -0400 Subject: [PATCH] Add unsubscribe command The unsubscribe command, available when in a message viewer context, enables users to easily unsubscribe from mailing lists. When the command is executed, aerc looks for a List-Unsubscribe header as defined in RFC 2369. If found, aerc will attempt to present the user with a suitable interface for completing the request. Currently, mailto and http(s) URLs are supported. In the case of a HTTP(S) URL, aerc will open the link in a browser. For mailto links, a new composer tab will be opened with a message filled out according to the URL. The message is not sent automatically in order to provide the user a chance to review it first. Closes #101 --- commands/msg/unsubscribe.go | 103 +++++++++++++++++++++++++++++++ commands/msg/unsubscribe_test.go | 41 ++++++++++++ doc/aerc.1.scd | 6 ++ 3 files changed, 150 insertions(+) create mode 100644 commands/msg/unsubscribe.go create mode 100644 commands/msg/unsubscribe_test.go diff --git a/commands/msg/unsubscribe.go b/commands/msg/unsubscribe.go new file mode 100644 index 0000000..d4a7e9a --- /dev/null +++ b/commands/msg/unsubscribe.go @@ -0,0 +1,103 @@ +package msg + +import ( + "bufio" + "errors" + "net/url" + "strings" + + "git.sr.ht/~sircmpwn/aerc/lib" + "git.sr.ht/~sircmpwn/aerc/widgets" +) + +// Unsubscribe helps people unsubscribe from mailing lists by way of the +// List-Unsubscribe header. +type Unsubscribe struct{} + +func init() { + register(Unsubscribe{}) +} + +// Aliases returns a list of aliases for the :unsubscribe command +func (Unsubscribe) Aliases() []string { + return []string{"unsubscribe"} +} + +// Complete returns a list of completions +func (Unsubscribe) Complete(aerc *widgets.Aerc, args []string) []string { + return nil +} + +// Execute runs the Unsubscribe command +func (Unsubscribe) Execute(aerc *widgets.Aerc, args []string) error { + if len(args) != 1 { + return errors.New("Usage: unsubscribe") + } + widget := aerc.SelectedTab().(widgets.ProvidesMessage) + headers := widget.SelectedMessage().RFC822Headers + if !headers.Has("list-unsubscribe") { + return errors.New("No List-Unsubscribe header found") + } + methods := parseUnsubscribeMethods(headers.Get("list-unsubscribe")) + aerc.Logger().Printf("found %d unsubscribe methods", len(methods)) + for _, method := range methods { + aerc.Logger().Printf("trying to unsubscribe using %v", method) + switch method.Scheme { + case "mailto": + return unsubscribeMailto(aerc, method) + case "http", "https": + return unsubscribeHTTP(method) + default: + aerc.Logger().Printf("skipping unrecognized scheme: %s", method.Scheme) + } + } + return errors.New("no supported unsubscribe methods found") +} + +// parseUnsubscribeMethods reads the list-unsubscribe header and parses it as a +// list of angle-bracket <> deliminated URLs. See RFC 2369. +func parseUnsubscribeMethods(header string) (methods []*url.URL) { + r := bufio.NewReader(strings.NewReader(header)) + for { + // discard until < + _, err := r.ReadSlice('<') + if err != nil { + return + } + // read until < + m, err := r.ReadSlice('>') + if err != nil { + return + } + m = m[:len(m)-1] + if u, err := url.Parse(string(m)); err == nil { + methods = append(methods, u) + } + } +} + +func unsubscribeMailto(aerc *widgets.Aerc, u *url.URL) error { + widget := aerc.SelectedTab().(widgets.ProvidesMessage) + acct := widget.SelectedAccount() + composer := widgets.NewComposer(aerc.Config(), acct.AccountConfig(), + acct.Worker()) + composer.Defaults(map[string]string{ + "To": u.Opaque, + "Subject": u.Query().Get("subject"), + }) + composer.SetContents(strings.NewReader(u.Query().Get("body"))) + tab := aerc.NewTab(composer, "unsubscribe") + composer.OnSubjectChange(func(subject string) { + if subject == "" { + tab.Name = "unsubscribe" + } else { + tab.Name = subject + } + tab.Content.Invalidate() + }) + return nil +} + +func unsubscribeHTTP(u *url.URL) error { + return lib.OpenFile(u.String()) +} diff --git a/commands/msg/unsubscribe_test.go b/commands/msg/unsubscribe_test.go new file mode 100644 index 0000000..e4e6f25 --- /dev/null +++ b/commands/msg/unsubscribe_test.go @@ -0,0 +1,41 @@ +package msg + +import ( + "testing" +) + +func TestParseUnsubscribe(t *testing.T) { + type tc struct { + hdr string + expected []string + } + cases := []*tc{ + &tc{"", []string{}}, + &tc{"invalid", []string{}}, + &tc{", ", []string{ + "https://example.com", "http://example.com", + }}, + &tc{" is a URL", []string{ + "https://example.com", + }}, + &tc{", ", + []string{ + "mailto:user@host?subject=unsubscribe", "https://example.com", + }}, + &tc{"<>, ", []string{ + "", "https://example", + }}, + } + for _, c := range cases { + result := parseUnsubscribeMethods(c.hdr) + if len(result) != len(c.expected) { + t.Errorf("expected %d methods but got %d", len(c.expected), len(result)) + continue + } + for idx := 0; idx < len(result); idx++ { + if result[idx].String() != c.expected[idx] { + t.Errorf("expected %v but got %v", c.expected[idx], result[idx]) + } + } + } +} diff --git a/doc/aerc.1.scd b/doc/aerc.1.scd index 0b86f75..aa2e5ba 100644 --- a/doc/aerc.1.scd +++ b/doc/aerc.1.scd @@ -85,6 +85,12 @@ message list, the message in the message viewer, etc). *unread* Marks the selected message as unread. +*unsubscribe* + Attempt to automatically unsubscribe the user from the mailing list through + use of the List-Unsubscribe header. If supported, aerc may open a compose + window pre-filled with the unsubscribe information or open the unsubscribe + URL in a web browser. + ## MESSAGE LIST COMMANDS *cf*