Add docs

plugin.go

@@ -8,10 +8,17 @@ import (
 
 const pluginDir = "plugins"
 
+// Plugin extends koushin with additional functionality.
 type Plugin interface {
+	// Name should return the plugin name.
 	Name() string
+	// LoadTemplate populates t with the plugin's functions and templates.
 	LoadTemplate(t *template.Template) error
+	// SetRoutes populates group with the plugin's routes.
 	SetRoutes(group *echo.Group)
+	// Inject is called prior to rendering a template. It can extend the
+	// template data by setting new items in the Extra map.
 	Inject(name string, data interface{}) error
+	// Close is called when the plugin is unloaded.
 	Close() error
 }

server.go

@@ -14,9 +14,10 @@ const cookieName = "koushin_session"
 
 const messagesPerPage = 50
 
+// Server holds all the koushin server state.
 type Server struct {
 	Sessions *SessionManager
-	Plugins []Plugin
+	Plugins  []Plugin
 
 	imap struct {
 		host     string
@@ -98,11 +99,13 @@ func newServer(imapURL, smtpURL string) (*Server, error) {
 type Context struct {
 	echo.Context
 	Server  *Server
-	Session *Session
+	Session *Session // nil if user isn't logged in
 }
 
 var aLongTimeAgo = time.Unix(233431200, 0)
 
+// SetSession sets a cookie for the provided session. Passing a nil session
+// unsets the cookie.
 func (ctx *Context) SetSession(s *Session) {
 	cookie := http.Cookie{
 		Name:     cookieName,
@@ -127,6 +130,7 @@ type Options struct {
 	Theme            string
 }
 
+// New creates a new server.
 func New(e *echo.Echo, options *Options) error {
 	s, err := newServer(options.IMAPURL, options.SMTPURL)
 	if err != nil {

session.go

@@ -23,8 +23,9 @@ func generateToken() (string, error) {
 	return base64.URLEncoding.EncodeToString(b), nil
 }
 
-var ErrSessionExpired = errors.New("session expired")
+var errSessionExpired = errors.New("session expired")
 
+// AuthError wraps an authentication error.
 type AuthError struct {
 	cause error
 }
@@ -33,6 +34,7 @@ func (err AuthError) Error() string {
 	return fmt.Sprintf("authentication failed: %v", err.cause)
 }
 
+// Session is an active user session. It may also hold an IMAP connection.
 type Session struct {
 	manager            *SessionManager
 	username, password string
@@ -49,6 +51,8 @@ func (s *Session) ping() {
 	s.pings <- struct{}{}
 }
 
+// Do executes an IMAP operation on this session. The IMAP client can only be
+// used from inside f.
 func (s *Session) Do(f func(*imapclient.Client) error) error {
 	s.locker.Lock()
 	defer s.locker.Unlock()
@@ -65,6 +69,7 @@ func (s *Session) Do(f func(*imapclient.Client) error) error {
 	return f(s.imapConn)
 }
 
+// Close destroys the session. This can be used to log the user out.
 func (s *Session) Close() {
 	select {
 	case <-s.closed:
@@ -74,6 +79,8 @@ func (s *Session) Close() {
 	}
 }
 
+// SessionManager keeps track of active sessions. It connects and re-connects
+// to the upstream IMAP server as necessary. It prunes expired sessions.
 type SessionManager struct {
 	newIMAPClient func() (*imapclient.Client, error)
 
@@ -113,6 +120,8 @@ func (sm *SessionManager) get(token string) (*Session, error) {
 	return session, nil
 }
 
+// Put connects to the IMAP server and creates a new session. If authentication
+// fails, the error will be of type AuthError.
 func (sm *SessionManager) Put(username, password string) (*Session, error) {
 	c, err := sm.connect(username, password)
 	if err != nil {

template.go

@@ -21,6 +21,7 @@ type GlobalRenderData struct {
 	Username string
 	// TODO: list of mailboxes
 
+	// Additional plugin-specific data
 	Extra map[string]interface{}
 }
 
@@ -28,7 +29,8 @@ type GlobalRenderData struct {
 // template-specific fields.
 type RenderData struct {
 	Global GlobalRenderData
-	Extra  map[string]interface{}
+	// Additional plugin-specific data
+	Extra map[string]interface{}
 }
 
 func NewRenderData(ctx *Context) *RenderData {