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-rw-r--r--app/scripts/controllers/detect-tokens.js130
1 files changed, 130 insertions, 0 deletions
diff --git a/app/scripts/controllers/detect-tokens.js b/app/scripts/controllers/detect-tokens.js
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+++ b/app/scripts/controllers/detect-tokens.js
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+const Web3 = require('web3')
+const contracts = require('eth-contract-metadata')
+const { warn } = require('loglevel')
+const { MAINNET } = require('./network/enums')
+// By default, poll every 3 minutes
+const DEFAULT_INTERVAL = 180 * 1000
+const ERC20_ABI = [{'constant': true, 'inputs': [{'name': '_owner', 'type': 'address'}], 'name': 'balanceOf', 'outputs': [{'name': 'balance', 'type': 'uint256'}], 'payable': false, 'type': 'function'}]
+
+/**
+ * A controller that polls for token exchange
+ * rates based on a user's current token list
+ */
+class DetectTokensController {
+ /**
+ * Creates a DetectTokensController
+ *
+ * @param {Object} [config] - Options to configure controller
+ */
+ constructor ({ interval = DEFAULT_INTERVAL, preferences, network, keyringMemStore } = {}) {
+ this.preferences = preferences
+ this.interval = interval
+ this.network = network
+ this.keyringMemStore = keyringMemStore
+ }
+
+ /**
+ * For each token in eth-contract-metada, find check selectedAddress balance.
+ *
+ */
+ async detectNewTokens () {
+ if (!this.isActive) { return }
+ if (this._network.store.getState().provider.type !== MAINNET) { return }
+ this.web3.setProvider(this._network._provider)
+ for (const contractAddress in contracts) {
+ if (contracts[contractAddress].erc20 && !(this.tokenAddresses.includes(contractAddress.toLowerCase()))) {
+ this.detectTokenBalance(contractAddress)
+ }
+ }
+ }
+
+ /**
+ * Find if selectedAddress has tokens with contract in contractAddress.
+ *
+ * @param {string} contractAddress Hex address of the token contract to explore.
+ * @returns {boolean} If balance is detected, token is added.
+ *
+ */
+ async detectTokenBalance (contractAddress) {
+ const ethContract = this.web3.eth.contract(ERC20_ABI).at(contractAddress)
+ ethContract.balanceOf(this.selectedAddress, (error, result) => {
+ if (!error) {
+ if (!result.isZero()) {
+ this._preferences.addToken(contractAddress, contracts[contractAddress].symbol, contracts[contractAddress].decimals)
+ }
+ } else {
+ warn(`MetaMask - DetectTokensController balance fetch failed for ${contractAddress}.`, error)
+ }
+ })
+ }
+
+ /**
+ * Restart token detection polling period and call detectNewTokens
+ * in case of address change or user session initialization.
+ *
+ */
+ restartTokenDetection () {
+ if (!(this.isActive && this.selectedAddress)) { return }
+ this.detectNewTokens()
+ this.interval = DEFAULT_INTERVAL
+ }
+
+ /**
+ * @type {Number}
+ */
+ set interval (interval) {
+ this._handle && clearInterval(this._handle)
+ if (!interval) { return }
+ this._handle = setInterval(() => { this.detectNewTokens() }, interval)
+ }
+
+ /**
+ * In setter when selectedAddress is changed, detectNewTokens and restart polling
+ * @type {Object}
+ */
+ set preferences (preferences) {
+ if (!preferences) { return }
+ this._preferences = preferences
+ preferences.store.subscribe(({ tokens }) => { this.tokenAddresses = tokens.map((obj) => { return obj.address }) })
+ preferences.store.subscribe(({ selectedAddress }) => {
+ if (this.selectedAddress !== selectedAddress) {
+ this.selectedAddress = selectedAddress
+ this.restartTokenDetection()
+ }
+ })
+ }
+
+ /**
+ * @type {Object}
+ */
+ set network (network) {
+ if (!network) { return }
+ this._network = network
+ this.web3 = new Web3(network._provider)
+ }
+
+ /**
+ * In setter when isUnlocked is updated to true, detectNewTokens and restart polling
+ * @type {Object}
+ */
+ set keyringMemStore (keyringMemStore) {
+ if (!keyringMemStore) { return }
+ this._keyringMemStore = keyringMemStore
+ this._keyringMemStore.subscribe(({ isUnlocked }) => {
+ if (this.isUnlocked !== isUnlocked) {
+ this.isUnlocked = isUnlocked
+ if (isUnlocked) { this.restartTokenDetection() }
+ }
+ })
+ }
+
+ /**
+ * Internal isActive state
+ * @type {Object}
+ */
+ get isActive () {
+ return this.isOpen && this.isUnlocked
+ }
+}
+
+module.exports = DetectTokensController