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costcalc/js/money.js
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money.js
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/*!
* money.js / fx() v0.2
* Copyright 2014 Open Exchange Rates
*
* JavaScript library for realtime currency conversion and exchange rate calculation.
*
* Freely distributable under the MIT license.
* Portions of money.js are inspired by or borrowed from underscore.js
*
* For details, examples and documentation:
* http://openexchangerates.github.io/money.js/
*/
(function(root, undefined) {
// Create a safe reference to the money.js object for use below.
var fx = function(obj) {
return new fxWrapper(obj);
};
// Current version.
fx.version = '0.2';
/* --- Setup --- */
// fxSetup can be defined before loading money.js, to set the exchange rates and the base
// (and default from/to) currencies - or the rates can be loaded in later if needed.
var fxSetup = root.fxSetup || {
rates : {},
base : ""
};
// Object containing exchange rates relative to the fx.base currency, eg { "GBP" : "0.64" }
fx.rates = fxSetup.rates;
// Default exchange rate base currency (eg "USD"), which all the exchange rates are relative to
fx.base = fxSetup.base;
// Default from / to currencies for conversion via fx.convert():
fx.settings = {
from : fxSetup.from || fx.base,
to : fxSetup.to || fx.base
};
/* --- Conversion --- */
// The base function of the library: converts a value from one currency to another
var convert = fx.convert = function(val, opts) {
// Convert arrays recursively
if (typeof val === 'object' && val.length) {
for (var i = 0; i< val.length; i++ ) {
val[i] = convert(val[i], opts);
}
return val;
}
// Make sure we gots some opts
opts = opts || {};
// We need to know the `from` and `to` currencies
if( !opts.from ) opts.from = fx.settings.from;
if( !opts.to ) opts.to = fx.settings.to;
// Multiple the value by the exchange rate
return val * getRate( opts.to, opts.from );
};
// Returns the exchange rate to `target` currency from `base` currency
var getRate = function(to, from) {
// Save bytes in minified version
var rates = fx.rates;
// Make sure the base rate is in the rates object:
rates[fx.base] = 1;
// Throw an error if either rate isn't in the rates array
if ( !rates[to] || !rates[from] ) throw "fx error";
// If `from` currency === fx.base, return the basic exchange rate for the `to` currency
if ( from === fx.base ) {
return rates[to];
}
// If `to` currency === fx.base, return the basic inverse rate of the `from` currency
if ( to === fx.base ) {
return 1 / rates[from];
}
// Otherwise, return the `to` rate multipled by the inverse of the `from` rate to get the
// relative exchange rate between the two currencies
return rates[to] * (1 / rates[from]);
};
/* --- OOP wrapper and chaining --- */
// If fx(val) is called as a function, it returns a wrapped object that can be used OO-style
var fxWrapper = function(val) {
// Experimental: parse strings to pull out currency code and value:
if ( typeof val === "string" ) {
this._v = parseFloat(val.replace(/[^0-9-.]/g, ""));
this._fx = val.replace(/([^A-Za-z])/g, "");
} else {
this._v = val;
}
};
// Expose `wrapper.prototype` as `fx.prototype`
var fxProto = fx.prototype = fxWrapper.prototype;
// fx(val).convert(opts) does the same thing as fx.convert(val, opts)
fxProto.convert = function() {
var args = Array.prototype.slice.call(arguments);
args.unshift(this._v);
return convert.apply(fx, args);
};
// fx(val).from(currency) returns a wrapped `fx` where the value has been converted from
// `currency` to the `fx.base` currency. Should be followed by `.to(otherCurrency)`
fxProto.from = function(currency) {
var wrapped = fx(convert(this._v, {from: currency, to: fx.base}));
wrapped._fx = fx.base;
return wrapped;
};
// fx(val).to(currency) returns the value, converted from `fx.base` to `currency`
fxProto.to = function(currency) {
return convert(this._v, {from: this._fx ? this._fx : fx.settings.from, to: currency});
};
/* --- Module Definition --- */
// Export the fx object for CommonJS. If being loaded as an AMD module, define it as such.
// Otherwise, just add `fx` to the global object
if (typeof exports !== 'undefined') {
if (typeof module !== 'undefined' && module.exports) {
exports = module.exports = fx;
}
exports.fx = fx;
} else if (typeof define === 'function' && define.amd) {
// Return the library as an AMD module:
define([], function() {
return fx;
});
} else {
// Use fx.noConflict to restore `fx` back to its original value before money.js loaded.
// Returns a reference to the library's `fx` object; e.g. `var money = fx.noConflict();`
fx.noConflict = (function(previousFx) {
return function() {
// Reset the value of the root's `fx` variable:
root.fx = previousFx;
// Delete the noConflict function:
fx.noConflict = undefined;
// Return reference to the library to re-assign it:
return fx;
};
})(root.fx);
// Declare `fx` on the root (global/window) object:
root['fx'] = fx;
}
// Root will be `window` in browser or `global` on the server:
}(this));
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