REBOL [ title: "Currency Rate Conversion Calculator" date: 9-feb-2013 file: %currency-calculator.r author: "Nick Antonaccio" purpose: { This example downloads and parses the current (live) US Dollar exchange rates from http://x-rates.com. The user selects from a list of currencies to convert to, then performs and displays the conversion from USD to the selected currency. All of the parsing occurs when the "Convert" button is clicked. The first half of the script is the simple Calculator GUI example taken from the first part of the tutorial at: http://re-bol.com/business_programming.html } ] view center-face layout [ origin 0 space 0x0 across f: field 200x40 font-size 20 return style btn btn 50x50 [append f/text face/text show f] btn "1" btn "2" btn "3" btn " + " return btn "4" btn "5" btn "6" btn " - " return btn "7" btn "8" btn "9" btn " * " return btn "0" btn "." btn " / " btn "=" [ attempt [f/text: form do f/text show f] ] return btn 200x35 "Convert" [ x: copy [] html: read http://www.x-rates.com/table/?from=USD&amount=1.00 html: find html "<img src='/themes/bootstrap/images/xrates_sm_tm.png'" parse html [ any [ thru {from=USD} copy link to {</a>} (append x link) ] to end ] rates: copy [] foreach rate x [ parse rate [thru {to=} copy c to {'>}] parse rate [thru {'>} copy v to end] if not error? try [to-integer v] [append rates reduce [c v]] ] currency: request-list "Select Currency:" extract rates 2 rate: to-decimal select rates currency attempt [alert rejoin [currency ": " (rate * to-decimal f/text)]] ] ]