May 24, 2019

利用 Node-RED 結合 Line Bot，在匯率低於數值時自動傳送信息。

使用 Node-RED 從台灣銀行網站自動抓取日幣匯率，結合 Messaging API 可以做到當日幣匯率低於一個數值時自動發送信息到你的手機。

Step .1

申請 Line Developer 帳號 & Messaging API

網址：https://developers.line.biz/

wp-image-299

申請完成後進到 Products 頁面，點選 Messaging API

wp-image-313
wp-image-314

設定提供者名稱（自己取名或公司名稱）

wp-image-308

填寫APP基本資料

wp-image-316

App icon
- Line Bot 使用者圖像
App name
- Line Bot 使用者名稱
App description
- App 描述
Category
- App 分類
Subcategory
- App 子分類
Privacy Policy URL（非必填）
- 隱私政策
Terms Of Use URL（非必填）
- 使用條款

閱讀完使用條款之後按下『同意』

wp-image-317

確認資料沒問題，勾選帳號與 API 的使用條款後，按下 Create 就完成 Line Bot 的初期設定了

wp-image-310

Step .2

設定 Messaging API

上一步驟完成後就會看到這樣的畫面，點進去你剛建立好的 App。

wp-image-318

進去找到『Messaging settings』的部分

wp-image-326

這裡有四個選項：

Channel access token (long-lived)
- 生成令牌，用來存取 API，他會問你重新生成令牌後，原本的令牌要多久後才會失效，依照你個人需求填寫。
Use webhooks
- 是否要使用 webhooks，他會把傳送給這個Line Bot的信息轉送到指定網址。
- 設定為：Enabled
Webhook URL
- webhooks 網址位置，用來接收信息。
- 設定為：https://nodered.com/line_hook
- 將 noderd.com 換成你 Node-RED 的對外名稱，要有 SSL。
Allow bot to join group chats
- 允許加入聊天群組，可以回復群組信息或推送信息到群組。
- 進去後在 Chet 的下方可以設定是否允許。

Step .3

導入 Node-RED Flow

點選『Copy』複製以下代碼，匯入 Node-RED

[{ "id": "f4a1039.77816", "type": "tab", "label": "Line Bot JPY", "disabled": false, "info": "" }, { "id": "1cdf8c88.5fb8d3", "type": "inject", "z": "f4a1039.77816", "name": "", "topic": "", "payload": "", "payloadType": "date", "repeat": "3600", "crontab": "", "once": false, "onceDelay": 0.1, "x": 220, "y": 120, "wires": [["e523d1ed.87656"]] }, { "id": "e523d1ed.87656", "type": "http request", "z": "f4a1039.77816", "name": "", "method": "GET", "ret": "txt", "url": "http://rate.bot.com.tw/xrt?Lang=zh-TW", "tls": "", "x": 410, "y": 120, "wires": [["cc67386b.69cc48"]] }, { "id": "cc67386b.69cc48", "type": "html", "z": "f4a1039.77816", "name": "filter", "property": "payload", "outproperty": "payload", "tag": ".rate-content-cash.text-right.print_hide", "ret": "html", "as": "single", "x": 569, "y": 120, "wires": [["6f5c428c.c222ec"]] }, { "id": "6f5c428c.c222ec", "type": "function", "z": "f4a1039.77816", "name": "Get JPY Currency", "func": "var currency = 0.28;\n\nvar data = {\n    jpy: Number(msg.payload[15])\n}\n\nvar isLow =  flow.get('isLow') || false;\nmsg.payload = data\nif (data.jpy < currency && !isLow) {\n    isLow = true;\n    flow.set('isLow', isLow);\n    return msg;\n}\nif (data.jpy > currency && isLow) {\n    isLow = false;\n    flow.set('isLow', isLow);\n}", "outputs": 1, "noerr": 0, "x": 754, "y": 120, "wires": [["ef3dd37a.900db", "3d5e1d3d.8d0e92"]] }, { "id": "3d5e1d3d.8d0e92", "type": "debug", "z": "f4a1039.77816", "name": "", "active": false, "tosidebar": true, "console": false, "tostatus": false, "complete": "payload", "x": 1004, "y": 120, "wires": [] }, { "id": "ef3dd37a.900db", "type": "function", "z": "f4a1039.77816", "name": "傳送信息", "func": "CHANNEL_ACCESS_TOKEN = 'Messaging API Token';\nUSER_ID = '使用者ID(不是Line ID)';\nmessage = {\n    type:'text',\n    text:'目前日圓匯率：'+msg.payload.jpy\n};\nheaders = {\n    'Content-Type': 'application/json; charset=UTF-8',\n    'Authorization': 'Bearer ' + CHANNEL_ACCESS_TOKEN,\n};\npayload = {\n    'to':  USER_ID,\n    'messages': [message]\n};\nmsg.headers = headers;\nmsg.payload = payload;\nreturn msg;", "outputs": 1, "noerr": 0, "x": 994, "y": 170, "wires": [["1a1d9d91.e25812"]] }, { "id": "1a1d9d91.e25812", "type": "http request", "z": "f4a1039.77816", "name": "Messaging API 傳送", "method": "POST", "ret": "txt", "url": "https://api.line.me/v2/bot/message/push", "tls": "", "x": 1216, "y": 170, "wires": [[]] }, { "id": "115048dd.aa6ef7", "type": "http in", "z": "f4a1039.77816", "name": "Messaging API 接收", "url": "/line_hook", "method": "post", "upload": false, "swaggerDoc": "", "x": 239, "y": 203, "wires": [["c3a26b18.b658b8"]] }, { "id": "c3a26b18.b658b8", "type": "debug", "z": "f4a1039.77816", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "x": 434, "y": 203, "wires": [] }, { "id": "9035f1cb.02bb5", "type": "inject", "z": "f4a1039.77816", "name": "發送測試信息", "topic": "", "payload": "{\"jpy\":\"測試信息\"}", "payloadType": "json", "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "x": 732, "y": 202, "wires": [["ef3dd37a.900db"]] }]