JavaScript to get currency exchange rates from Yahoo Finance as JSONP. No XHR!

yahoo_exchange_rates_jsonp.html

Get exchange rate as JSONP via YQL.

YQL Console: http://developer.yahoo.com/yql/console

Query (USD to SEK): select rate,name from csv where url='http://download.finance.yahoo.com/d/quotes?s=USDSEK%3DX&f=l1n' and columns='rate,name'

Example code:

<script type="text/javascript">

  function getRate(from, to) {
    var script = document.createElement('script');
    script.setAttribute('src', "http://query.yahooapis.com/v1/public/yql?q=select%20rate%2Cname%20from%20csv%20where%20url%3D'http%3A%2F%2Fdownload.finance.yahoo.com%2Fd%2Fquotes%3Fs%3D"+from+to+"%253DX%26f%3Dl1n'%20and%20columns%3D'rate%2Cname'&format=json&callback=parseExchangeRate");
    document.body.appendChild(script);
  }

  function parseExchangeRate(data) {
    var name = data.query.results.row.name;
    var rate = parseFloat(data.query.results.row.rate, 10);
    alert("Exchange rate " + name + " is " + rate);
  }
  
  getRate("SEK", "USD");
  getRate("USD", "SEK");
  
</script>