Introduction

bitcoinprices.js is a JavaScript library for presenting Bitcoin prices with currency conversion.

Example:

Features

• Sourcing data from bitcoinaverage.com exchange rate market data API
• Easy to place on any web page and Bitcoin store
• Web and mobile friendly
• Integrates with Bootstrap front-end framework
• Integrates with Font Awesome icon font
• Change currency through a dropdown menu
• Change currency by clicking / touching a price on the page
• Manual currency conversions
• npm packaged for browserify consumption.

See also

• Liberty Music Store is an online store which allows musicians to sell their songs and receive Bitcoins.. The source code of Liberty Music Store is on Github, so you can check it for the integration example.

• The sister project bitcoinaaddress.js for making bitcoin payments and QR codes.

Demos

Demo with clickable bitcoin prices, bitcoin price menu and manu bitcoin price conversion.

BitWatcher

Installation

No server-side components needed.

You must have jQuery (version 1.9 or later) installed.

Put bitcoinprices.js in your application.

You manually need to call bitcoinprices.init() to trigger the loading of exchange rate data and making price switching logic to work:

<script src="bitcoinprices.js"></script>
<script>
    $(document).ready(function() {
        bitcoinprices.init({

            // Where we get bitcoinaverage data
            url: "https://api.bitcoinaverage.com/ticker/all",

            // Which of bitcoinaverages value we use to present prices
            marketRateVariable: "24h_avg",

            // Which currencies are in shown to the user
            currencies: ["BTC", "USD", "EUR", "CNY"],

            // Special currency symbol artwork
            symbols: {
                "BTC": "<i class='fa fa-btc'></i>"
            },

            // Which currency we show user by the default if
            // no currency is selected
            defaultCurrency: "BTC",

            // How the user is able to interact with the prices
            ux : {
                // Make everything with data-btc-price HTML attribute clickable
                clickPrices : true,

                // Build Bootstrap dropdown menu for currency switching
                menu : true,

                // Allow user to cycle through currency choices in currency:

                clickableCurrencySymbol:  true
            },

            // Allows passing the explicit jQuery version to bitcoinprices.
            // This is useful if you are using modular javascript (AMD/UMD/require()),
            // but for most normal usage you don't need this
            jQuery: jQuery,

            // Price source data attribute
            priceAttribute: "data-btc-price",

            // Price source currency for data-btc-price attribute.
            // E.g. if your shop prices are in USD
            // but converted to BTC when you do Bitcoin
            // checkout, put USD here.
            priceOrignalCurrency: "BTC"

        });
    });
</script>

All configuration parameters can be omitted. Then defaults from bitcoinprices.js is used (defaultConfig variable).

How it works

Your templating language must output Bitcoin prices with attribute:

<p>
    <div>Example price: <span data-btc-price="1.0">1.0 BTC</span></div>
</p>

• You manually initialize the library with and give it a config you want to use, including bitcoinaverage.com API URL. See the demo for an example.
• bitcoinprices.init() fires HTML document marketdataavailable event when the script manages to load exchange rates
• Whenever the user changes price presentation format HTML document activecurrencychange event is fired
• You can manually call bitcoinprices.convert() to convert between any currencies supported by bitcoinaverage.com
• You can manually call call bitcoinprices.updatePrices() if your own JavaScripts sets the active currency and all prices on the page are updatd.

It is suggested that you cache bitcoinaverage.com API output on a local server with proper cache headers. This may considerably speed up your site and reduces bitcoinaverage.com load.

Drupal and UberCart integration

Here is another example how bitcoinprices.js is used with popular Drupal content management system and its UberCart eCommerce add on.

An example live site, It's time for plan B.

Integration instructions

Change UberCart templates to output price as data-price-usd attribute.

Example modification to node--production.tpl.php:

$usd_price = round(render($content['sell_price']['#value']) , 2);

<span data-price-usd="<?=$usd_price ?>"><?=$usd_price ?></span>

Include bitcoinprices.js in your CSS.

Add CSS styles for .clickable-price selector (prices become clickable only when succesful market data exchange rates have been downloaded from bitcoinaverage). clickable-price CSS class is added automatically you don't need to add it to your templates:

.clickable-price {
    cursor: pointer;
    border-bottom: 1px #888 dashed;
}

Include an initialization JavaScript snippet as a separate JS file:

/**
 * Drupal + Ubercart integration for bitcoinprices.js
 *
 * Make Bitcoin prices clickable, based on the dollar amount.
 *
 * Scan document for elements with `data-price-usd` attributes,
 * make them clickable.
 */

(function($) {

    // Entry point to processing
    $(document).ready(function() {

        bitcoinprices.init({

            // Which currencies are in shown to the user
            currencies: ["BTC", "USD", "EUR", "CNY"],

            // Which currency we show user by the default if
            // no currency is selected
            defaultCurrency: "USD",

            // How the user is able to interact with the prices
            ux : {
                // Make everything with data-btc-price HTML attribute clickable
                clickPrices : true,

                // Build Bootstrap dropdown menu for currency switching
                menu : false,
            },

            // Allows passing the explicit jQuery version to bitcoinprices.
            // This is useful if you are using modular javascript (AMD/UMD/require()),
            // but for most normal usage you don't need this
            jQuery: $,

            // Which HTML attribute hosts the price data and
            // makes elements clickable
            priceAttribute: "data-price-usd",

            // Which is the source currency for the prices
            priceOrignalCurrency: "USD"
        });
    });

})(jQuery);

Author

Mikko Ohtamaa (blog, Facebook, Twitter, Google+)

Contact for work and consulting offers.