embark/lib/contracts/code_templates/web3-connector.js.ejs

__mainContext.web3 = undefined;
__reduce(<%- connectionList %>,function(prev, value, next) {
  if (prev === false) {
    return next(null, false);
  }

  if (value === '$WEB3' && (typeof web3 !== 'undefined' && typeof Web3 !== 'undefined')) {
    web3.setProvider(web3.givenProvider);
  } else if (value !== '$WEB3' && (typeof Web3 !== 'undefined' && ((typeof web3 === 'undefined') || (typeof web3 !== 'undefined' && (!web3.isConnected || (web3.isConnected && !web3.isConnected())))))) {
    if (value.indexOf('ws://') >= 0) {
      web3.setProvider(new Web3.providers.WebsocketProvider(value));
    } else {
      web3.setProvider(new Web3.providers.HttpProvider(value));
    }
  } else if (value === '$WEB3') {
    return next(null, '');
  }

  __getAccounts(function(err, account) {
    if (err) {
      next(null, true)
    } else {
      next(null, false)
    }
  });
}, function(err, _result) {
  __getAccounts(function(err, accounts) {
    <% if (warnAboutMetamask) { %>
    if (web3.eth.currentProvider && web3.eth.currentProvider.isMetaMask) {
      console.log("%cNote: Embark has detected you are in the development environment and using Metamask, please make sure Metamask is connected to your local node", "font-size: 2em");
    }
    <% } %>
    if (accounts) {
      web3.eth.defaultAccount = accounts[0];
    }
    <%- done  %>
  });
});