SSE
2019-10-22
html5提供了Server-Sent Events方法，通过服务器发送事件，更新能够自动到达。
使用示例：
if (typeof (EventSource) !== "undefined") {
var source = new EventSource("server.php");
source.onopen = function () {
console.log("Connection to server opened.");
};
source.onmessage = function (event) {
document.getElementById("result").innerHTML += event.data + "<br>";
};
source.onerror = function () {
console.log("EventSource failed.");
};
}
else {
document.getElementById("result").innerHTML = "抱歉，你的浏览器不支持 server-sent 事件...";
}
服务端：
<?php
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
date_default_timezone_set('PRC');
$i = 0;
while (++$i < 100) {
echo "id: " . $i . "\tdate: " . date('c') . ";\n\n";
ob_flush();
flush();
sleep(1);
}