mirror of
https://github.com/kremalicious/metamask-extension.git
synced 2024-12-12 20:57:12 +01:00
138 lines
4.2 KiB
JavaScript
138 lines
4.2 KiB
JavaScript
const ObservableStore = require('obs-store')
|
|
const extend = require('xtend')
|
|
const log = require('loglevel')
|
|
|
|
// every ten minutes
|
|
const POLLING_INTERVAL = 600000
|
|
|
|
class CurrencyController {
|
|
|
|
/**
|
|
* Controller responsible for managing data associated with the currently selected currency.
|
|
*
|
|
* @typedef {Object} CurrencyController
|
|
* @param {object} opts Overrides the defaults for the initial state of this.store
|
|
* @property {array} opts.initState initializes the the state of the CurrencyController. Can contain an
|
|
* currentCurrency, conversionRate and conversionDate properties
|
|
* @property {string} currentCurrency A 2-4 character shorthand that describes a specific currency, currently
|
|
* selected by the user
|
|
* @property {number} conversionRate The conversion rate from ETH to the selected currency.
|
|
* @property {string} conversionDate The date at which the conversion rate was set. Expressed in in milliseconds
|
|
* since midnight of January 1, 1970
|
|
* @property {number} conversionInterval The id of the interval created by the scheduleConversionInterval method.
|
|
* Used to clear an existing interval on subsequent calls of that method.
|
|
*
|
|
*/
|
|
constructor (opts = {}) {
|
|
const initState = extend({
|
|
currentCurrency: 'usd',
|
|
conversionRate: 0,
|
|
conversionDate: 'N/A',
|
|
}, opts.initState)
|
|
this.store = new ObservableStore(initState)
|
|
}
|
|
|
|
//
|
|
// PUBLIC METHODS
|
|
//
|
|
|
|
/**
|
|
* A getter for the currentCurrency property
|
|
*
|
|
* @returns {string} A 2-4 character shorthand that describes a specific currency, currently selected by the user
|
|
*
|
|
*/
|
|
getCurrentCurrency () {
|
|
return this.store.getState().currentCurrency
|
|
}
|
|
|
|
/**
|
|
* A setter for the currentCurrency property
|
|
*
|
|
* @param {string} currentCurrency The new currency to set as the currentCurrency in the store
|
|
*
|
|
*/
|
|
setCurrentCurrency (currentCurrency) {
|
|
this.store.updateState({ currentCurrency })
|
|
}
|
|
|
|
/**
|
|
* A getter for the conversionRate property
|
|
*
|
|
* @returns {string} The conversion rate from ETH to the selected currency.
|
|
*
|
|
*/
|
|
getConversionRate () {
|
|
return this.store.getState().conversionRate
|
|
}
|
|
|
|
/**
|
|
* A setter for the conversionRate property
|
|
*
|
|
* @param {number} conversionRate The new rate to set as the conversionRate in the store
|
|
*
|
|
*/
|
|
setConversionRate (conversionRate) {
|
|
this.store.updateState({ conversionRate })
|
|
}
|
|
|
|
/**
|
|
* A getter for the conversionDate property
|
|
*
|
|
* @returns {string} The date at which the conversion rate was set. Expressed in milliseconds since midnight of
|
|
* January 1, 1970
|
|
*
|
|
*/
|
|
getConversionDate () {
|
|
return this.store.getState().conversionDate
|
|
}
|
|
|
|
/**
|
|
* A setter for the conversionDate property
|
|
*
|
|
* @param {number} conversionDate The date, expressed in milliseconds since midnight of January 1, 1970, that the
|
|
* conversionRate was set
|
|
*
|
|
*/
|
|
setConversionDate (conversionDate) {
|
|
this.store.updateState({ conversionDate })
|
|
}
|
|
|
|
/**
|
|
* Updates the conversionRate and conversionDate properties associated with the currentCurrency. Updated info is
|
|
* fetched from an external API
|
|
*
|
|
*/
|
|
async updateConversionRate () {
|
|
let currentCurrency
|
|
try {
|
|
currentCurrency = this.getCurrentCurrency()
|
|
const response = await fetch(`https://api.infura.io/v1/ticker/eth${currentCurrency.toLowerCase()}`)
|
|
const parsedResponse = await response.json()
|
|
this.setConversionRate(Number(parsedResponse.bid))
|
|
this.setConversionDate(Number(parsedResponse.timestamp))
|
|
} catch (err) {
|
|
log.warn(`MetaMask - Failed to query currency conversion:`, currentCurrency, err)
|
|
this.setConversionRate(0)
|
|
this.setConversionDate('N/A')
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Creates a new poll, using setInterval, to periodically call updateConversionRate. The id of the interval is
|
|
* stored at the controller's conversionInterval property. If it is called and such an id already exists, the
|
|
* previous interval is clear and a new one is created.
|
|
*
|
|
*/
|
|
scheduleConversionInterval () {
|
|
if (this.conversionInterval) {
|
|
clearInterval(this.conversionInterval)
|
|
}
|
|
this.conversionInterval = setInterval(() => {
|
|
this.updateConversionRate()
|
|
}, POLLING_INTERVAL)
|
|
}
|
|
}
|
|
|
|
module.exports = CurrencyController
|