How to get events result using web3 1.0.0 version

Question

 function depositToEscrow(bytes32 _id) public payable returns(uint) {
    DepositToEscrow(msg.sender,orderdata[_id].buyer,msg.value,orderdata[_id].amount);  
}

suppose this is my function in a smart contract. How to get the result of the event "DepositToEscrow" using web3

Answer 1

You have to take care of following things:

1. Use websocket provider in order to subscribe to events in web3.js 1.0. For example, if you are using local TestRPC then instantiate the web3 as by using your websocket port (here in this case its 8545):

   const web3 = new Web3(Web3.givenProvider || "ws://127.0.0.1:8545");
   

2. The example code for myContract having an event of MyEvent will be like:

   myContract.events.MyEvent ({
     fromBlock: 'latest',
     toBlock: 'latest'
   }, function(error, result) {
     if (!error) {
       console.log(result);
     } else {
       console.log(error);
     }
   });
   

Note: in the above block of code, I'm watching for the events in 'latest' block mined. The reason is, this block of code is the same as we have watch method in the older version. This will only watch for events that are not fired yet. If you want to get all the events, you have to use getPastEvents:

    myContract.getPastEvents('MyEvent', {
      fromBlock: 0,
      toBlock: 'latest'
    }, function(error, result) {
      if (!error) {
        console.log(result);
      } else {
        console.log(error);
      }
    });

For more details, see the Docs

Answer 2

For 1.0.0, it's:

yourContract.events.YourEvent(function(error, event) {
});

Answer 3

Something like the code below:

var depositToEscrow = [YourContractInstance].DepositToEscrow({}, 'latest');
depositToEscrow.watch(function(error, result) {
    if (result) {
        // your required code
    } else {
        // your required logic
    }
});