比特币、以太仿 - 加密货币与法定货币转换

[threetown]

• 加密货币转换计算器
• 法定汇率

https://free.currencyconverterapi.com/api/v6/convert?q=USD_CNY

• Crypto Currency MySQL Datatypes ?
• web3.0 api
• fomo3d
• 以太坊上的矿工费 (gas)
• 0x3411356C1f0Bf5D859464eD2AC54DD2C222519B7

算法函数

• 法定货币

function format_fiat(val) {
    if (val >= 100000 || val == 0) {
        val = Formatter.toLocaleString(Math.round(val));
    } else if (val >= 1) {
        val = Formatter.toLocaleString(val, {
            minDecimalPlaces: 2,
            maxDecimalPlaces: 2
        });
    } else if (val < 0.000001) {
        val = Number(val).toExponential(2)
    } else {
        val = Formatter.toLocaleString(val, {
            minDecimalPlaces: 6,
            maxDecimalPlaces: 6
        });
    }
    return val;
}

• 加密货币

function format_crypto(val) {
    return format_crypto_helper(val, 0.00000001, 3, 8, 8)
}

function format_crypto_helper(val, expenonentialThreshold, exponentialDigits, minDecimalPlaces, maxDecimalPlaces) {
    if (val >= 1000 || val == 0) {
        val = Formatter.toLocaleString(Math.round(val));
    } else if (val >= 1) {
        val = Formatter.toLocaleString(val, {
            minDecimalPlaces: minDecimalPlaces,
            maxDecimalPlaces: maxDecimalPlaces
        });
    } else {
        if (val < expenonentialThreshold) {
            val = Number(val).toExponential(exponentialDigits)
        } else {
            val = Formatter.toLocaleString(val, {
                minDecimalPlaces: minDecimalPlaces,
                maxDecimalPlaces: maxDecimalPlaces
            });
        }
    }
    return val;
}


function format_crypto_graph_label(val) {
    return format_crypto_helper(val, 0.00000001, 3, 2, 8)
}

function format_crypto_short(val) {
    return format_crypto_helper(val, 0.01, 1, 2, 2)
}

• 格式化

var Formatter = (function() {
    var _locale = Cookies.get('_locale') || undefined;
    var supportsLocaleOptions = !!(typeof Intl == 'object' && Intl && typeof Intl.NumberFormat == 'function');
    var _toLocaleString = function(val) {
        if (supportsLocaleOptions) {
            return val.toLocaleString(_locale);
        }
        return val.toLocaleString();
    };
    var _toLocaleStringWithDecimalPlaces = function(val, minDecimalPlaces, maxDecimalPlaces) {
        if (supportsLocaleOptions) {
            return val.toLocaleString(_locale, {
                minimumFractionDigits: minDecimalPlaces,
                maximumFractionDigits: maxDecimalPlaces
            });
        }
        return val.toFixed(maxDecimalPlaces);
    };
    var toLocaleString = function(value, options) {
        var num = Number(value);
        if (isNaN(num)) {
            return value;
        }
        var minDecimalPlaces = options && options.minDecimalPlaces;
        var maxDecimalPlaces = options && options.maxDecimalPlaces;
        if (minDecimalPlaces === undefined || maxDecimalPlaces === undefined) {
            return _toLocaleString(num);
        }
        return _toLocaleStringWithDecimalPlaces(num, minDecimalPlaces, maxDecimalPlaces);
    }
    return {
        toLocaleString: toLocaleString
    };
}
)();

业务代码

• 调用 coinmarketcap 接口，获取加密货币信息

var tickerData = {};

var apiDomain = "https://api.coinmarketcap.com";
$.ajax({
  url: apiDomain + "/v1/ticker/?limit=0",
}).done(function( data ) {
  //Load Crypto Rates 加密货币
  for (i=0; i < data.length; i++) {
    tickerData[data[i]['id']] = data[i]['price_usd'];
  }
  //Load Fiat Rates 法定汇率（暂不考虑此汇率）
  var fiatRates = $("#currency-exchange-rates").data();
  for (currency in fiatRates) {
    tickerData["__fiat-" + currency] = fiatRates[currency]
  }

  // 业务逻辑，开始转换啦！
  convert();

}).fail(function( data ) {
  console.error(data);
});

• convert()

function convert() {
  var form = getFormValues();
  var fromId = form.fromId;                   //  "ethereum"
  var fromName = form.fromName;      //  "Ethereum (ETH)"
  var toId = form.toId;                           //  "bitcny"
  var toName = form.toName;              //  "bitCNY (BITCNY)"
  var conversionAmount = form.conversionAmount;                // 1

  if (isNaN(conversionAmount) || conversionAmount == "") {
    conversionAmount = 0;
  }
  conversionAmount = parseFloat(conversionAmount);

  var fromAmount = tickerData[fromId];                                    //  "ethereum"
  var toAmount = tickerData[toId];                                             //  "bitcny"
  var convertedAmount = conversionAmount * fromAmount / toAmount;     // convertedAmount = 1389.3264952911668, conversionAmount = 1

  if (toId.substring(0,6) == "__fiat") {
    convertedAmount = format_fiat(convertedAmount);
  } else {
    convertedAmount = format_crypto(convertedAmount);       convertedAmount = "1,389"
  }

  var resultLeft = conversionAmount + " " + fromName;
  $('#conversion-result-left').html(resultLeft);
  $('#conversion-result-value').html(convertedAmount);
  $('#conversion-result-value-currency').html(toName);
}