Flow - Design and control conversation flow

Overview

Model the structured conversation flow between the user and a chatbot, or between whatever you want.

A Simple Example

import (
    "fmt"
    . "github.com/dyrkin/flow"
)
//Human data storage
type UserData struct {
    login    string
    password string
}
//bot emulator
func newBot(humanChan chan string) *Flow {
    var awaitCommand *Step
    var askEmail *Step
    var askPassword *Step
    //wait for command from human
    awaitCommand =
        OnReply(func(msg Message, data Data) *NextStep {
            switch msg {
            case "register":
                return Goto(askEmail).Using(&UserData{})
            case "quit":
                return End()
            }
            return DefaultHandler()(msg, data)
        })
    //ask human for email
    askEmail =
        Ask(func(data Data) {
            humanChan <- "please send your email"
        }).OnReply(func(msg Message, data Data) *NextStep {
            email := msg.(string)
            humanData := data.(*UserData)
            humanData.login = email
            return Goto(askPassword)
        })
    //ask human for password
    askPassword =
        Ask(func(data Data) {
            humanChan <- "please send your password"
        }).OnReply(func(msg Message, data Data) *NextStep {
            password := msg.(string)
            humanData := data.(*UserData)
            humanData.password = password
            return End().Using(humanData)
        })
    return New(awaitCommand)
}
func main() {
    humanChan := make(chan string)
    //bot conversation flow
    bot := newBot(humanChan)
    go func() {
        messages := []string{"some@email.com", "some password"}
        index := 0
        for {
            select {
            case <-humanChan:
                bot.Send(messages[index])
                index++
            }
        }
    }()
    dataChan := bot.Start()
    bot.Send("register")
    collectedData := <-dataChan
    fmt.Println(collectedData)
}

The basic strategy is to define Steps and specifying initial step while instantiating the Flow:

• New(<initial step>) creates a flow with the initial step specified.
• Start() starts the flow and returns a chan where the collected data will be sent after end of the flow.
• Ask(<data fn>) executes immediately after Start() is called.
• OnReply(<message fn>) executes when a data from the user is received.
• <message fn> must return next step or end the flow

The code will produce the following output:

UserData{login: “some@email.com”, password: “some password”}

Full working example can be found there: example/conversation.go