currency-rates-store

A storage bot to sync exchange rates with any exchange rates api

Example

const CurrStore = require('currency-rates-store');
const pull = require('currency-restapi-currencylayer').Live('YOUR_ACCESS_KEY');


// Default on `USD`, and 3 hours between requests
var store = CurrStore({pull: pull});


// CurrencyRatesStore is an EventEmitter, 
['error', 'warn', 'info'].forEach(lv=> store.on(lv, e=> console.log(e)));


store.on('load', store=>{

  // convert €100 EUR to USD 
  console.log(store.convert(100).from('EUR').to('USD'));
  
  // convert € 1 EUR to USD
  console.log(store.from('EUR').to('CAD'));
  
  // or skip `.from()`, if the `store.base` is `USD`
  console.log(store.convert(100).to('EUR'));
  
  // simply pass the pair
  console.log(store.pair('EURUSD'));
  
  // or pass the symbol one by one
  console.log(store.rate('USD', 'EUR'));
  
  // same as above, if the exchange rates storage is based on `USD`
  console.log(store.rate('EUR'));
  

});

Options

• pull: An async function. it should callback the latest rates in the following structure. Usually, it wraps exchange rates sites api. Following are modules designed for currency-rates-store

  • currency-restapi-currencylayer
  • currency-restapi-openexchange

• base: 'USD|EUR|GBP...'. which currency this rates should be based on. Default: USD

• wait: refresh in milliseconds. Default to 3 hours between refreshs. minimum 10 minutes. However, if any error occurred from pull callback, it will use util-retry to retry the pull 3 times.

{
  base: 'USD|EUR|GBP'   - tell which currency this rates is based on
  rates: {
    USD: 1,             - If base == 'USD', this value should be 1
    GBP: ...
    EUR: ...
    ...
  },
  ts: {Milliseconds}
}

Event: 'load'

function (store) { } Emitted when the first valid rates is recieved

Event: 'error'

function (error) { }

See source code

Event: 'warn'

function (msg) {}

Emitted when the received rates is based on another currency which is different from base property configured on this store. A rebase calculation will happen, and emit this warning.

Event: 'info'

function (info) {} Emitted for logging purpose.