feat: server push demo

esonoma · Jul 19, 2022 · 2346eb5 · 2346eb5
1 parent 8db7c07
commit 2346eb5
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diff --git a/extensions/server-push/app.js b/extensions/server-push/app.js
@@ -0,0 +1,40 @@
+const http = require("http");
+const {
+  setEventStreamHeaders,
+  sendEvent,
+  reuseServerPushChanel,
+} = require("./eventstream");
+const url = require("url");
+
+global.serverPushChanel = null;
+const server = http.createServer((req, res) => {
+  const parsedUrl = url.parse(req.url);
+  const { pathname, query } = parsedUrl;
+
+  res.setHeader("access-control-allow-origin", "*");
+
+  if (pathname === "/") {
+    res.writeHead(200, { "Content-Type": "text/html" });
+    res.end("<h1>Hello World</h1>");
+  }
+
+  if (pathname === "/evt") {
+    setEventStreamHeaders(res);
+    global.serverPushChanel = res;
+    sendEvent(req, res);
+  }
+
+  // client message
+  if (pathname === "/msg") {
+    res.writeHead(200, { "Content-Type": "text/plain" });
+    res.end(new Date().toString());
+
+    if (global.serverPushChanel) {
+      reuseServerPushChanel(global.serverPushChanel, query, res);
+    }
+  }
+});
+
+server.listen(8900, "localhost", () => {
+  console.log("Server is running on port 8900");
+});
diff --git a/extensions/server-push/eventstream.js b/extensions/server-push/eventstream.js
@@ -0,0 +1,29 @@
+exports.setEventStreamHeaders = function (res) {
+  res.setHeader("Content-Type", "text/event-stream");
+  res.setHeader("Cache-Control", "no-cache");
+  res.setHeader("Connection", "keep-alive");
+  res.setHeader("Access-Control-Allow-Origin", "*");
+  res.setHeader("Access-Control-Allow-Credentials", true);
+};
+
+exports.sendEvent = function (req, res) {
+  setInterval(() => {
+    res.write(
+      `data: ${JSON.stringify({
+        type: "event",
+        mode: "ping",
+        message: "server push, ping",
+      })} \n\n`
+    );
+  }, 3000);
+};
+
+exports.reuseServerPushChanel = function (serverPushChanel, query, res) {
+  serverPushChanel.write(
+    `data: ${JSON.stringify({
+      type: "event",
+      mode: "msg",
+      message: query,
+    })} \n\n`
+  );
+};
diff --git a/extensions/server-push/index.html b/extensions/server-push/index.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Client</title>
+  </head>
+  <body>
+    <h2>发送消息</h2>
+    <label for="m">
+      <input type="text" id="m" />
+    </label>
+    <button type="button" id="sendBtn">发送</button>
+
+    <h2>接受消息</h2>
+    <h4 class="connect-status">Pending connection...</h4>
+    <ul class="message-container"></ul>
+  </body>
+
+  <script>
+    const eventSource = new EventSource("http://localhost:8900/evt");
+    eventSource.onopen = (event) => {
+      document.querySelector(".connect-status").innerHTML =
+        "Connected to server";
+    };
+    eventSource.onmessage = (event) => {
+      const message = JSON.parse(event.data);
+      const messageNode = document.createElement("li");
+      if (message.mode === "msg") {
+        messageNode.setAttribute("style", "color: red");
+      }
+      messageNode.innerHTML = `<strong>${
+        message?.mode
+      }</strong>: ${decodeURIComponent(message.message)}`;
+      document.querySelector(".message-container").appendChild(messageNode);
+    };
+
+    sendMessage();
+
+    function sendMessage() {
+      const messageInput = document.querySelector("#m");
+      const sendBtn = document.querySelector("#sendBtn");
+
+      sendBtn.addEventListener("click", () => {
+        fetch(
+          "http://localhost:8900/msg" + "?message=" + messageInput.value
+        ).then((response) => {
+          console.log(response);
+        });
+      });
+    }
+  </script>
+</html>
diff --git a/extensions/server-push/package.json b/extensions/server-push/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "server-push",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "nodemon app.js"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "nodemon": "^2.0.19"
+  }
+}