[day14] 接收使用者的Line讯息

结合先前的

1. 产生channel access token
2. 设定heroku

可以开始建立一个服务器接收由Line官方送过来的资讯，此处假设你使用Heroku进行开发，在Line Developers Console内，将Channel-->Messaging API-->Webhook URL设定为

https://[AppName].herokuapp.com/callback

并将Auto-reply messages 与 Greeting messages同样设为Disabled，方法为:

1. 点选右侧的Edit
2. Line Offficial Account Manager-->回应设定
3. 停用加入好友的欢迎讯息与自动回应讯息

实作并部署回声机器人

此机器人功能:回传传给机器人的文字讯息

如果未安装line-bot-sdk套件

pip install line-bot-sdk

修改Server.py，加入以下内容

from flask import Flask, request, abort

from linebot import (
    LineBotApi, WebhookHandler
)
from linebot.exceptions import (
    InvalidSignatureError
)
from linebot.models import (
    MessageEvent, TextMessage, TextSendMessage,
)
import os

app = Flask(__name__)
api = Api(app)

#LCAT为Channel Access Token
line_bot_api = LineBotApi(os.environ['LCAT'])

#Cst为Channel secret
handler = WebhookHandler(os.environ['Cst'])

@app.route("/callback", methods=['POST'])
def callback():
    # get X-Line-Signature header value
    signature = request.headers['X-Line-Signature']

    # get request body as text
    body = request.get_data(as_text=True)
    app.logger.info("Request body: " + body)

    # handle webhook body
    try:
        handler.handle(body, signature)
    except InvalidSignatureError:
        print("Invalid signature. Please check your channel access token/channel secret.")
        abort(400)

    return 'OK'

@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    line_bot_api.reply_message(
        event.reply_token,
        TextSendMessage(text=event.message.text))

部署:

git add .
git commit -m "Echo Bot"
git push heroku main

此时从Line传讯息给机器人，你应该就可以收得到来自机器人的回讯

加机器人为好友

Line Developers --> Channel Setting --> Messaging API --> Bot information --> Bot basic ID or QR code

使用你的手机搜寻Bot basic ID或扫描QR code加机器人为好友

过程解析

这是一个由Line官方传送过来的Webhook Sample

{
  "destination": "xxxxxxxxxx",
  "events": [
      {
          "type": "message",
          "message": {
              "type": "text",
              "id": "14353798921116",
              "text": "Hello, world"
          },
          "timestamp": 1625665242211,
          "source": {
              "type": "user",
              "userId": "U80696558e1aa831..."
          },
          "replyToken": "757913772c4646b784d4b7ce46d12671",
          "mode": "active"
      },
      {
          "type": "follow",
          "timestamp": 1625665242214,
          "source": {
              "type": "user",
              "userId": "Ufc729a925b3abef..."
          },
          "replyToken": "bb173f4d9cf64aed9d408ab4e36339ad",
          "mode": "active"
      },
      {
          "type": "unfollow",
          "timestamp": 1625665242215,
          "source": {
              "type": "user",
              "userId": "Ubbd4f124aee5113..."
          },
          "mode": "active"
      }
  ]
}

1. 手机发讯息给Line
2. Line传送通知给bot server(webhook URL)的webhook
3. WebhookHandler验证headers中的x-line-signature栏位签章，除了使用SDK进行验证，也可以手动进行验证
4. 将资料传送给配对的执行函数，如本次范例中使用的MessageEvent与TextMessage，进行处理
5. 使用Line SDK回覆讯息，回传TextSendMessage(text=event.message.text)) 以此范例还说，就是Hello, world

跑完接收与发送，之後要开始把功能逐渐拼起来组成专案了