chart.js

var data = {
    labels: [
        "1", "2", "3", "4", "5"
    ],
    datasets: [
        
    ]
};


var dat = {
	
}
var options = {
    animation: {
        animateScale: false
    },
    responsive: false,
    scales: {
        yAxes: [
            {
                ticks: {
                    
                    beginAtZero: true                                                                    
                }
            }
        ],
            xAxes: [
            {
                ticks: {
                    
                    beginAtZero: true                                                                    
                }
            }
        ]
    }
};
var ctx = document.getElementById("myChart").getContext('2d');                                           
var myBarChart = new Chart(ctx, {
    type: 'bubble',
    data: data,
    options: options
});
var button = document.getElementById("sendAjax")
 
button.addEventListener("click", function() {
    sendAjax('http://localhost:3000/');
})
 
function sendAjax(url) {
    var oReq = new XMLHttpRequest();
 
    oReq.open('POST', url);
    oReq.setRequestHeader('Content-Type', "application/json") // json 형태로 보낸다                         
    oReq.send();
 
    oReq.addEventListener('load', function() {
        var result = JSON.parse(oReq.responseText);
        var score = result.score;
        var comp_data = data.datasets[0].data;
 
        for (var i = 0; i < comp_data.length; i++) {
            comp_data[i] = score[i];
        }
 
        data.datasets[0].data = comp_data;
        myBarChart.update();
    })
}