JSCrowdSaleInfo.js

<div class="col-12 col-md-4 text-center text-bold">
    <h2 class="number" id="contract-balance">$135 000</h2>
    <p class="text mt-0">Баланс смарт-контракта</p>
</div>
<div class="col-12 col-md-4 text-center text-bold">
    <h2 class="number" id="investors-count">10</h2>
    <p class="text mt-0">Количество инвесторов</p>
</div>
<div class="col-12 col-md-4 text-center text-bold">
    <h2 class="number" id="tokens-count">10 342</h2>
    <p class="text mt-0">Общее количество купленных токенов</p>
</div>
<script>
var tokenAddress = '0x241684ef15683ca57c42d8f4bb0e87d3427ddf1c';
var tokenDecimals = 8;
var tokenPrice = 2.8;
var crowdsaleAddress = '0x3881c403a2ed46d171f813a0dac67dcc438d6f91';
var totalTokens = 504000;
var apiKey = '1KPI5JUY9JBUHQMH7IQ12F2DINIVXD69VH';
var updateInterval = 60000; // 60 secs


var tokensСountElement = document.getElementById('tokens-count');
var investorsСountElement = document.getElementById('investors-count');
var contractBalanceElement = document.getElementById('contract-balance');

var updateTokensCount = function(){
    var xhr = new XMLHttpRequest();
    xhr.open('GET', 'https://api.etherscan.io/api?module=account&action=tokenbalance&contractaddress=' + tokenAddress + '&address=' + crowdsaleAddress + '&tag=latest&apikey=' + apiKey, false);
    xhr.send();
    if (xhr.status != 200) {
        tokensСountElement.innerHTML = '?';
    } else {
        var tokensCount = totalTokens - JSON.parse(xhr.responseText).result / (10**tokenDecimals);
        tokensСountElement.innerHTML = Math.round(tokensCount * 100) / 100;
        contractBalanceElement.innerHTML = '$' + (Math.round(tokensCount * tokenPrice * 100) / 100);
    }
};
updateTokensCount();
setInterval(updateTokensCount, updateInterval);

var updateInvestorsCount = function(){
    var xhr = new XMLHttpRequest();
    xhr.open('GET', 'http://api.etherscan.io/api?module=account&action=txlist&address=' + crowdsaleAddress + '&startblock=0&endblock=9999999999&apikey=' + apiKey, false);
    xhr.send();
    if (xhr.status != 200) {
        investorsСountElement.innerHTML = '?';
    } else {
        investorsСountElement.innerHTML = JSON.parse(xhr.responseText).result.filter(function(tx){
            return tx.to == crowdsaleAddress;
        }).length;
    }
};
updateInvestorsCount();
setInterval(updateInvestorsCount, updateInterval);

</script>