diff options
Merge branch 'develop' into no-inject-ani-gamer
Diffstat (limited to 'app/scripts/controllers/detect-tokens.js')
-rw-r--r-- | app/scripts/controllers/detect-tokens.js | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/app/scripts/controllers/detect-tokens.js b/app/scripts/controllers/detect-tokens.js new file mode 100644 index 000000000..195ec918a --- /dev/null +++ b/app/scripts/controllers/detect-tokens.js @@ -0,0 +1,130 @@ +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 |