我做了一个小的活动注册智能合约(通过使用solidity(((,因为我通过提供我的电子邮件ID和我想要的门票数量的详细信息来购买活动的门票。最后,我想知道我怎样才能找回我得到的细节。我正在使用testrpc,松露和私人网络。点击购买后,我在 tetrpc 终端中获得了这些详细信息
交易:
0x35e92857102b0dbacd43234d1ea57790405eb9bef956b245c6b7737bc23d011b 燃气使用量:106532 区块数:5 区块时间:周六 2月 03 2018 12:05:57 GMT+0530 (IST(
我解码交易 ID,如下所示:
gopi145@ubuntu:~/EventRegistration-POC/EventRegistration$ truffle console
truffle(development)> web3.eth.getTransaction('0x35e92857102b0dbacd43234d1ea57790405eb9bef956b245c6b7737bc23d011b')
{ hash: '0x35e92857102b0dbacd43234d1ea57790405eb9bef956b245c6b7737bc23d011b',
nonce: 4,
blockHash: '0x7c790dae57babfe40d68d8aad94913c2b748501c5734aec86cc3fcf0afc4f154',
blockNumber: 5,
transactionIndex: 0,
from: '0x031e060414a0d2573f5b10bc75c0894d72288292',
to: '0xa88a366e888bbccfb78092957ffc7760bc7c6db1',
value: BigNumber { s: 1, e: 18, c: [ 60000 ] },
gas: 200000,
gasPrice: BigNumber { s: 1, e: 0, c: [ 1 ] },
input: '0xa28f161c00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000b6d40676d61696c2e636f6d000000000000000000000000000000000000000000' }
truffle(development)>
但我没有得到购买时提供的详细信息。请告诉我该怎么做?
web3.eth.getTransaction(txHash)
将返回交易详细信息,如blockHash,transactionIndex,from,to等。
矿工挖块并添加到区块链需要一些时间。所以它不是即时的。
如果你想知道任何存储值在区块链中添加/修改到外部世界,那么我们需要在智能合约中提出 en 事件。
使用 Web3JS(JSON-RPC/WS-RPC(,您需要注册并侦听事件。当您的交易被挖掘时,您将收到一个事件。
事件将存储为日志,与存储相比,它非常便宜。没有人能够修改事件数据。
下面的代码相同。
坚固性代码:
pragma solidity ^0.4.17;
//Contract for storing ticket info
contract TicketRes {
event on_success_booking(address userId, string bookingId, string emailId);
//Ticket info having two storage values i.e email and userID
struct BookingInfo{
string emailId;
address userId;
}
//Map for saving all the info, assuming all ticket has unique id as key. Value is ticket info
mapping(bookingId=>BookingInfo) internal info;
function Book() public {
}
//Method will save all basic info, and will raise event.
function onBookingCompleted(address id, string bookingId, string emailId) public {
info[bookingId] = BookingInfo(emailId,userId);
on_success_booking(id, bookingId, emailId);
}
//You can get info by using bookingid at any point of time.
function getBookingInfo(string bookingId) public constant returns(string, address){
return (info[bookingId].emailId, info[bookingId].userId);
}
}
现在的Javascript代码:
// Contract deployed address.
var contractAddress = "0x06433f4fc50423f71329597f50fb0a42cfecb11f";
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://127.0.0.1:8545"));
}
//Open build folder and you will find contact json file copy the appropriate JSON and paste it there.
var contractABI = web3.eth.contract(/** ABI Here **/);
//Connected contract to your local network
var contract = contractABI.at(contractAddress);
//Loading booking event function.
var booking_event = web3.sha3('on_success_booking(address,string,string)');
//Watching events, when onBookingCompleted() tran's mined then event get triggered. You can get all previous events also. for that need to apply filters.
booking_event.watch((error, result) => {
if(error){
console.log("error",error);
}
console.log("Result", result); //result.args holds values, result.args.id, result.args.bookingId and result.args.emailid
});