Ethereum Cookbook

How to do it...

We can watch events from DApp using the following steps:

1. Consider the following contract, which emits events for each state changing operation. There is a dedicated Essential events–EVM Logger recipe in the previous chapter, which describes the process of writing events in solidity:

pragma solidity ^0.4.22;contract eventEmitter {        event simpleEvent(address _sender);    event indexedEvent(address indexed _sender, uint _id);        function simpleEmit() public {        // do something        emit simpleEvent(msg.sender);    }        function indexedEmit(uint _id) public {        // do something        emit indexedEvent(msg.sender, _id);    }}

2. Watch an emitted event from a decentralized application using the following method. The syntax may be slightly different for various ...