How to let Dapp connect to network from Mist browser (ver 0.8) without starting geth with rpc options manually?

Question

After Mist 0.8, I made the following change on my Dapp so that it uses existing web3 connection if connected via Mist.

https://github.com/makoto/blockparty/commit/cbea6e2990e5699532acecd5aedcf4b0180faf7d

However, the dapp is failing to connect to network (eg web3.currentProvider.isConnected() is returning false) when opened it from Mist.

It can be connected if I kill geth process opened by Mist, and launch geth manually with --rpc rpccorsdomain=* options enabled, but that defeats the purpose of having Mist browser.

Am I missing anything to make my Dapp "Mist ready"?

Answer 1

I followed this example https://gist.github.com/frozeman/fbc7465d0b0e6c1c4c23

And this is what I did

if(typeof web3 !== 'undefined'){   // eg: If accessed via mist
  provider = web3.currentProvider; // Keep provider info given from mist `web3` object
  web3 = new Web3;                 // Re-instantiate `web3` using `Web3` from Dapp
}else{
  provider = new Web3.providers.HttpProvider("http://localhost:8545");
  let web3 = new Web3;             // Define and instantiate `web3` if accessed from web browser
}
web3.setProvider(provider);

Here is the basic logic

1. check if mist or web3 object is already defined by mist.
2. If yes, keep the existing provider info, then re-instantiate web3 using Web3, which comes from your Dapp. Make sure you do not re-define the variable(eg: var web3).
3. If no, you instantiate provider and define web3 object.