How to make automatic currency conversion against the ruble?

Question

JavaScript

Hello!

There is a need to set up automatic price conversion from rubles to some others.

There are a number of blocks:

<span class="rub">1000</span> рублей
<span class="usd">????</span> долларов
<span class="eur">????</span> евро
<span class="yah">????</span> гривен
<span class="byr">????</span> белорусских рублей

It is desirable that the conversion takes place relative to the current exchange rate of the Central Bank.
How to do it?

Sincerely,
Alexander.

Answer 1

Many thanks to @EnterSandman and @Taraflex for the hints. I solved the problem in the following way:
Create a PHP exchange rate parser file:

<?php 
 $content = get_content(); 
 $pattern = "#<Valute ID=\"([^\"]+)[^>]+>[^>]+>([^<]+)[^>]+>[^>]+>[^>]+>[^>]+>[^>]+>[^>]+>([^<]+)[^>]+>[^>]+>([^<]+)#i"; 
 preg_match_all($pattern, $content, $out, PREG_SET_ORDER); 
 
 $usd = ""; 
 $eur = ""; 
 $byr = ""; 
 $uah = ""; 
 $kzt = ""; 

 foreach($out as $cur) 
 
 { 
   if($cur[2] == 840) $usd  = str_replace(",",".",$cur[4]); 
   if($cur[2] == 978) $eur   = str_replace(",",".",$cur[4]); 
   if($cur[2] == 974) $byr   = str_replace(",",".",$cur[4]); 
   if($cur[2] == 980) $uah   = str_replace(",",".",$cur[4]); 
   if($cur[2] == 398) $kzt   = str_replace(",",".",$cur[4]); 
 } 

 echo "<span id=\"bank-usd\">".$usd."</span> <span id=\"bank-eur\">".$eur."</span> <span id=\"bank-byr\">".$byr."</span> <span id=\"bank-uah\">".$uah."</span> <span id=\"bank-kzt\">".$kzt."</span>"; 
 
 function get_content() 

 { 
   $link = "http://www.cbr.ru/scripts/XML_daily.asp"; 
   $fd = fopen($link, "r"); 
   $text=""; 
   echo "";
   while (!feof ($fd)) $text .= fgets($fd, 4096); 
   fclose ($fd); 
   return $text; 
 }

?>

Anywhere in the HTML document, we insert the download of this file, and wrap all its contents in display: none.
We create a JS file that processes currency rates and converts our 1000 rubles into each of them:

var rub = 1000;
var bankUSD = document.getElementById('bank-usd').innerText;
var bankEUR = document.getElementById('bank-eur').innerText;
var bankBYR = document.getElementById('bank-byr').innerText;
var bankUAH = document.getElementById('bank-uah').innerText;
var bankKZT = document.getElementById('bank-kzt').innerText;

document.getElementById('rub').innerHTML = rub;
document.getElementById('usd').innerHTML = (rub/bankUSD).toFixed(2);
document.getElementById('eur').innerHTML = (rub/bankEUR).toFixed(2);
document.getElementById('byr').innerHTML = (10000*rub/bankBYR).toFixed(0);
document.getElementById('uah').innerHTML = (10*rub/bankUAH).toFixed(1);
document.getElementById('kzt').innerHTML = (100*rub/bankKZT).toFixed(0);

For the Belarusian, Kazakh and Ukrainian currencies, I had to add a few more zeros for the correct output.
And in any convenient place where we need, we output:

<span id="rub"></span> рублей
<span id="byr"></span> рублей
<span id="uah"></span> гривен
<span id="kzt"></span> тенге
<span id="usd"></span> долларов
<span id="eur"></span> евро

Answer 2

I'm not strong in JS, but I'll give you direction
jsfiddle.net/Bn7X9

Answer 3

The exchange rate can be found here
www.cbr.ru/scripts/XML_daily.asp

Answer 4

National Bank to help.
But if the resource is not Russian, you can get a lawsuit by converting the zloty to the ruble at the Russian rate.