# SIG 2019

# SIG 2019

Add the following to "dapp -- Resources"

* JavaScript: https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js
* CSS: https://cdn.bootcss.com/twitter-bootstrap/3.3.7/css/bootstrap.min.css

The "dapp -- CSS" should be empty

https://opendapps.secondstate.io/SIG2019_1576286389667.html

<p>欢迎参加2019海纳亚洲大会！请各位嘉宾在下方输入名字领取 Addison-Wesley 新出版的 <a href="https://www.amazon.com/Building-Blockchain-Apps-Michael-Yuan/dp/0135172322/">Buidling Blockchain App</a> 一书</p><p><center><img width="320px" src="https://blog.secondstate.io/images/20191002-book-etc-01.png"></center></p>

<p>Sponsored by Second State</p><ul><li>全球领先的区块链技术，为多个全球著名公链提供技术</li><li>无币联盟公链</li><li>为AI，云计算，区块链优化的下一代计算基础设施</li><li>为云原生为服务而生</li></ul>

HTML

<div class="container">
    <br/>
    <div class="jumbotron">
        <p class="lead" id="greeting">欢迎参加2019海纳亚洲大会！请各位嘉宾在下方输入名字领取 Addison-Wesley 新出版的 <a href="https://www.amazon.com/Building-Blockchain-Apps-Michael-Yuan/dp/0135172322/">Buidling Blockchain App</a> 一书</p>
        <hr/>
        <form id="form">
            <div class="form-group">
                <label for="name">您的姓名</label>
                <input type="text" class="form-control" id="name" placeholder="">
            </div>
            <div class="form-group">
                <label for="organization">您的联系方式</label>
                <input type="text" class="form-control" id="organization" placeholder="">
            </div>
            <button type="button" id="submit" class="btn btn-primary">发送</button>
        </form>
        <div id="formSubmitted" style="display:none">共识上链中，请等 20 秒 ...</div>
        <p id="me" style="display:none"><span id="myname" class="badge badge-info"></span> 已经签到，谢谢！链上地址 <span id='addr'></span></p>
    </div>
    
    <h4>已经签到</h4>
    <table class="table table-striped">
        <thead>
            <tr>
                <th scope="col">链上地址</th>
                <th scope="col">姓名</th>
                <th scope="col">联系方式</th>
            </tr>
        </thead>
        <tbody id="checkins">
        </tbody>
    </table>

    <p style="text-align:center">永久记录在 <a target="_blank" href="https://app.cybermiles.io/">CyberMiles</a> 公链</p>
</div>

JS

/* Don't modify */

var instance = null;
window.addEventListener('web3Ready', function() {
  var contract = web3.ss.contract(abi);
  instance = contract.at(cAddr);
  reload();
});

function reload() {
    var greeting = "";
    var success = "";
    instance.getGreeting(function (e, r) {
        greeting = r[0];
        success  = r[1];
        $("#greeting").html(greeting);
    });
    
    $("#formSubmitted").css("display", "none");
    $("#me").css("display", "none");
    web3.ss.getAccounts(function (e, address) {
        if (!e) {
            instance.getCheckin(address, function (ee, result) {
                if (result[0]) {
                    $("#greeting").html(success);
                    $("#greeting").css("font-size", "14px");
                    $("#form").css("display", "none");
                    $("#me").css("display", "block");
                    $("#myname").html(result[0]);
                    $("#addr").html(shorten(address.toString()));
                }
            });
            
            var checkins = "";
            instance.getAddrs(function (ee, addrs) {
                addrs.forEach(function(addr) {
                    instance.getCheckin(addr, function (ee, r) {
                        if (!ee) {
                            var content = $("#checkins").html();
                            if (content.indexOf(r[0])!==-1 && content.indexOf(r[1])!==-1) {
                                // skip
                            } else {
                                checkins = "<tr><td><a href='https://www.cmttracking.io/address/" + addr + "'>" + shorten(addr) + "</a></td><td>" + r[0] + "</td><td>" + r[1] + "</td></tr>" + checkins;
                                $("#checkins").html(checkins);
                            }
                        }
                    });
                });
            });
            $("#checkins").html(checkins);
        }
    });
}

$("#submit").click(function() {
    var n = $("#name").val().trim();
    var o = $("#organization").val().trim();
    if (!o) {
        o = " ";
    }

    if (!n) {
      alert("请输入姓名");
      return false;
    }

    web3.ss.getAccounts(function (e, address) {
        if (!e) {
            if (confirm("确认 " + n + " [" + o + "]")) {
                $("#formSubmitted").css("display", "block");
                instance.addCheckin (n, o, {
                    gas: 499000,
                    gasPrice: 0
                }, function (ee, r) {
                    if (ee) {
                        window.alert("Failed at " + address);
                    }
                });
                setTimeout(function () {
                    reload ();
                }, 20 * 1000);
            }
        }
    });
    return false;
});
      
function shorten (addr) {
    return addr.replace(/(.{7})..+/, "$1…");
}

SOL

pragma solidity >= 0.4.0;

contract CheckIns {

    address owner;
    string public greeting;
    string public success;
    struct Checkin {
        string name;
        string organization;
    }
    mapping (address => Checkin) checkins;
    address [] addrs;

    constructor (string _greeting, string _success) public {
        owner = msg.sender;
        greeting = _greeting;
        success = _success;
    }

    function setGreeting (string _greeting, string _success) public {
        require (msg.sender == owner);
        greeting = _greeting;
        success = _success;
    }

    function getGreeting () public constant returns(string, string) {
        return (greeting, success);
    }

    function addCheckin (string _name, string _organization) public {
        checkins[msg.sender] = Checkin(_name, _organization);
        addrs.push(msg.sender);
    }

    function getCheckin (address _addr) public constant returns(string, string) {
        return (checkins[_addr].name, checkins[_addr].organization);
    }

    function getAddrs () public constant returns (address []) {
        return addrs;
    }
}