Middleware

bot.go

@@ -10,12 +10,21 @@ import (
 )
 
 type bot struct {
+	echo.API
 	chatID  int64
 	me      *echo.User
-	echo.API
 	data    StateData
 	lock    sync.Mutex
 	state   Runnable
+	handler UpdateHandler
+}
+
+func DefaultHandler(u *Update) error {
+	err := u.Bot.state.Call(u)
+	if err != nil {
+		u.LogError("", err, true)
+	}
+	return err
 }
 
 func (b *bot) Update(u *echo.Update) {
@@ -30,8 +39,5 @@ func (b *bot) Update(u *echo.Update) {
 
 	b.lock.Lock()
 	defer b.lock.Unlock()
-	err := b.state.Call(upd)
+	b.handler(upd)
-	if err != nil {
-		upd.LogError("", err, true)
-	}
 }

command.go

@@ -1,16 +1,21 @@
 package nechotron
 
-import "strings"
+import (
+	"fmt"
+	"strings"
+)
 
 type Command struct {
 	Body        string
 	IsAdminOnly bool
+	Description string
 }
 
-func NewCommand(body string, isAdminOnly bool) *Command {
+func NewCommand(body string, desc string, isAdminOnly bool) *Command {
 	return &Command{
 		Body:        body,
 		IsAdminOnly: isAdminOnly,
+		Description: desc,
 	}
 }
 func (c *Command) String() string {
@@ -21,4 +26,12 @@ func (c *Command) Param(text string) string {
 	return strings.TrimPrefix(text, "/"+c.Body+" ")
 }
 
+func MakeCommandList(commands []*Command, format string) string {
+	result := ""
+	for _, command := range commands {
+		result += fmt.Sprintf(format, command.String(), command.Description)
+	}
+	return result
+}
+
 // func HandleCommand(command *Command, handler cmdFunc) (bool, error)

dispatcher.go

@@ -4,8 +4,8 @@ import (
 	"strings"
 )
 
+type UpdateHandler func(u *Update) error
 type dispatchHandler func(u *Update) (bool, error)
-type updateHandler func(u *Update) error
 type commandHandler func(u *UpdateCommand) error
 
 type Dispatcher struct {
@@ -45,7 +45,7 @@ func (d *Dispatcher) HandleCommand(command *Command, handler commandHandler) *Di
 	return d
 }
 
-func (d *Dispatcher) HandleFilter(filter FilterFn, handler updateHandler) *Dispatcher {
+func (d *Dispatcher) HandleFilter(filter FilterFn, handler UpdateHandler) *Dispatcher {
 	newHandler := func(u *Update) (bool, error) {
 		if !filter(u) {
 			return false, nil

middleware.go

@@ -0,0 +1,3 @@
+package nechotron
+
+type Middleware func(next UpdateHandler) UpdateHandler

nechotron.go

@@ -10,6 +10,7 @@ type Nechotron struct {
 	Token        string
 	DefaultState Runnable
 	ApiServer    string
+	Handler      UpdateHandler
 }
 
 func NewTron(token string, defaultState *State) *Nechotron {
@@ -20,6 +21,7 @@ func NewTron(token string, defaultState *State) *Nechotron {
 	return &Nechotron{
 		Token:        token,
 		DefaultState: state,
+		Handler:      DefaultHandler,
 	}
 }
 
@@ -34,6 +36,7 @@ func (n *Nechotron) newBot(chatID int64) echo.Bot {
 		API:     a,
 		state:   n.DefaultState,
 		data:    make(StateData),
+		handler: n.Handler,
 	}
 	b.state = n.DefaultState
 	return b
@@ -44,3 +47,8 @@ func (n *Nechotron) DispatchPoll() error {
 	log.Println("Nechotron poll dispatcher started")
 	return dispatcher.Poll()
 }
+
+func (n *Nechotron) Use(mid Middleware) *Nechotron {
+	n.Handler = mid(n.Handler)
+	return n
+}

update.go

@@ -14,7 +14,7 @@ type U echotron.Update
 var emptyOpts = echotron.MessageOptions{}
 
 type Event interface {
-	Update
+	Upd() *echotron.Update
 }
 
 type Update struct {