Câmbio

A simple Electron app to display current dollar conversion rates. It keeps an icon in your system tray showing the latest rate and also a chart showing recent trend. Clicking it shows past rates and that day's high/low:

Data is updated once a minute, queried from UOL Economia - Cotações.

Installation

The installation process is currently manual. Make sure you have Node.js installed, clone this repo and run:

npm install

After that, simply run:

npm start

And the application should start.

Endpoint response

This is how the web site calls the endpoint:

https://cotacoes.economia.uol.com.br/cambioJSONChart.html?callback=grafico.parseData&type=d&cod=BRL&mt=off

It returns an HTML excerpt like this:

grafico.parseData([{"RangeY":{"value":0.003944999999999999}},[{"ask":3.7024,"ts":1533557340000},{"ask":3.7076,"ts":1533557940000},{"ask":3.7102,"ts":1533558540000}],{"high":"3.7276","pctChange":"0.475","open":"0","bid":"3.7235","ask":"3.7247","timestamp":1533575340000,"name":"Dólar Comercial","low":"3.7012","notFresh":false,"varBid":"0.0176"}]);

But if we remove the callback parameter, the result is pure JSON, ready to parse, like this (formatted for readability):

[
  {
    "RangeY": {
      "value": 0.003944999999999999
    }
  },
  [
    {
      "ask": 3.7024,
      "ts": 1533557340000
    },
    {
      "ask": 3.7076,
      "ts": 1533557940000
    },
    {
      "ask": 3.7102,
      "ts": 1533558540000
    }
  ],
  {
    "high": "3.7276",
    "pctChange": "0.472",
    "open": "0",
    "bid": "3.7234",
    "ask": "3.7246",
    "timestamp": 1533575940000,
    "name": "Dólar Comercial",
    "low": "3.7012",
    "notFresh": false,
    "varBid": "0.0175"
  }
]