Develop Bitcoin Price Feed Plugin Using .Net Core

Crypto currency has become household topic of discussions. Especially with how NFT (non-fungible tokens) assets are being talked about, more and more people want to know about crypto currencies. There are a lot of crypto currencies out there. But the currency that people mostly talk about is Bitcoin. A lot more people are trading Bitcoins and other crypto currencies. A topic that people have on their mind is to know the current price of Bitcoin.

I decided to develop a plugin for my latest Blog framework. This plugin fetches current Bitcoin price from CoinDesk.

See it in action at World of Hobby Craft blog site.

{"time":{"updated":"Sep 18, 2013 17:27:00 UTC",
"updatedISO":"2013-09-18T17:27:00+00:00"},
"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index. Non-USD currency 
data converted using hourly conversion rate from openexchangerates.org",
"bpi":{"USD":{"code":"USD","symbol":"$","rate":"126.5235",
"description":"United States Dollar",
"rate_float":126.5235},
"GBP":{"code":"GBP","symbol":"£","rate":"79.2495",
"description":"British Pound Sterling",
"rate_float":79.2495},
"EUR":{"code":"EUR","symbol":"€","rate":"94.7398",
"description":"Euro","rate_float":94.7398}}}

The price data is returned as a dictionary of currency and rates inside bpi property. Here is the code that I have put together fetch the feed and then serialize into a proper C# class.

Feed Data Structures

public record CoindeskFeedModel:BaseAmgrModel
    {
        [JsonProperty("time")]
        public PriceIndexUpdateTime UpdateTime { get; set; }
        [JsonProperty("bpi")]
        public Dictionary PriceIndexValueDictionary { get; set; }

        public record PriceIndexUpdateTime
        {
            [JsonProperty("updated")]
            public string UpdateTimeUtc { get; set; }
        }
        public record PriceIndexValue
        {
            [JsonProperty("code")]
            public string Code { get; set; }
            [JsonProperty("description")]
            public string Description { get; set; }
            [JsonProperty("symbol")]
            public string Symbol { get; set; }
            [JsonProperty("rate")]
            public double Rate { get; set; }
        }
    }

.Net Core Http Client To Fetch Bitcoin Price

public class BitcoinPriceController: BasePluginController
    {
        #region Fields

        private readonly IHttpClientFactory _httpClientFactory;
        private readonly ILogger _logger;
        private readonly CoindeskFeedSettings _feedSettings;
        private const string PriceIndexFeedUrl = "https://api.coindesk.com/v1/bpi/currentprice.json";
        #endregion

        public BitcoinPriceController(IHttpClientFactory httpClientFactory,
            CoindeskFeedSettings feedSettings,
            ILogger logger)
        {
            _httpClientFactory = httpClientFactory;
            _feedSettings = feedSettings;
            _logger = logger;
        }
        [HttpPost]
        public async Task<IActionResult> LatestPrice()
        {
            try
            {
                var httpClient = _httpClientFactory.CreateClient(AmgrHttpDefaults.DefaultHttpClient);
                var priceFeed = await httpClient.GetStringAsync(string.IsNullOrEmpty
                  (_feedSettings.PriceFeedUrl) ? PriceIndexFeedUrl: _feedSettings.PriceFeedUrl);
                var coinDeskPriceIndexModel = JsonConvert.DeserializeObject<CoindeskFeedModel>(priceFeed);
                var priceIndexValues = new List<BitcoinPriceModel>();
                if (null == coinDeskPriceIndexModel) return Json(priceIndexValues);
                foreach (var priceIndexModel in coinDeskPriceIndexModel.PriceIndexValueDictionary)
                {
                    var dictionaryValue = coinDeskPriceIndexModel.PriceIndexValueDictionary[priceIndexModel.Key];
                    priceIndexValues.Add(new BitcoinPriceModel
                    {
                        UpdatedAtUtc = coinDeskPriceIndexModel.UpdateTime.UpdateTimeUtc,
                        Price = dictionaryValue.Rate,
                        Currency = dictionaryValue.Code,
                        CurrencySymbol = dictionaryValue.Symbol
                    });
                }

                return Json(priceIndexValues);
            }
            catch (Exception ex)
            {
                await _logger.ErrorAsync($"Error getting latest bitcoin price", ex);
            }

            return Json("");
        }
    }

I have wrapped the client side implementation in a jQuery ajax call that refreshes the data on a fixed interval.

<script asp-location="Footer" type="text/javascript">
    var bitCoinPriceUpdateInProgress = false;
    function getBitcoinPrices() {
        if (bitCoinPriceUpdateInProgress) return;
        bitCoinPriceUpdateInProgress = true;
        $.ajax({
            cache: false,
            type: "POST",
            url: "@Html.Raw(Url.RouteUrl("BitcoinPriceFeed"))",
            success: function (data, textStatus, jqXHR) {
                bitCoinPriceUpdateInProgress = false;
                if (null != data && data.length !== 0) {
                    var priceListElement = $("#bitcoin-price-list");
                    var updateTimeElement = $("#bitcoin-price-updatetime");
                    $(priceListElement).empty();
                    for (var i = 0; i < data.length; i++) {
                        var priceIndexValue = data[i];
                        $(priceListElement).append
                             ($("<li class='g-mb-2'><strong class='d-block g-font-size-30 g-line-height-1_2'>" 
                           + priceIndexValue.CurrencySymbol + priceIndexValue.Price + "</strong></li>"));
                        $(updateTimeElement).text(priceIndexValue.UpdatedAtUtc);
                    }
                }
            },
            error:function(jqXHR) {
                bitCoinPriceUpdateInProgress = false;
            },
            complete: function (jqXHR, textStatus) {
                bitCoinPriceUpdateInProgress = false;
                setTimeout(getBitcoinPrices, @refreshFrequency);
            }
        });
    }

    setTimeout(getBitcoinPrices, 0);
</script>

The plugin is developed along the guidelines of nopCommerce platform. If you are interested in including this in your nopCommerce plugin list, feel free to contact me. I can share the complete plugin with you. You will to have make some changes to adapt to namespace used by nopCommerce framework.