Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- javascript [2022-06-25 17:22:16] – [AJAX/AJAJ (fetch)] david
+++ javascript [2026-05-16 12:12:24] (aktuell) – [video screenshot] david
@@ Zeile 82: / Zeile 82: @@
 ===== Beispielprogramme =====
+==== backend ====
+=== test api ===
+API zum testen: Alle Anfragen werden geloggt und mit "Hello World!" und dem Status Code 418 (I'm a teapot) beantwortet.
+<code javascript test.js>
+"use strict";
+import express from "express";
+const app = express();
+const port = process.env.PORT || 3000;
+app.use(express.json());
+app.use((req, res, next) => {
+    const payload = {
+        body: req.body ?? null,
+        headers: req.headers ?? null,
+        url: req.url ?? null,
+    };
+    console.log(payload);
+    res.status(418);
+    res.send("Hello World!");
+    next();
+});
+app.listen(port);
+console.info(`Express started on port ${port}`);
+</code>
+<code json package.json>
+{
+  "name": "test",
+  "version": "1.0.0",
+  "license": "MIT",
+  "type": "module",
+  "main": "test.js",
+  "dependencies": {
+    "express": "^4.18.2"
+  },
+}
+</code>
+=== hello world webserver (deno) ===
+<code javascript hello-world.ts>
+import { serve } from "https://deno.land/std@0.126.0/http/server.ts";
+const port = 80;
+const handler = (): Response => {
+    return new Response("Hello World!");
+};
+serve(handler, { port });
+console.log(`Listening on http://localhost:${port}`);
+</code>
 ==== frontend ====
+=== video screenshot ===
+screenshot des ersten videos auf der aktuellen webseite
+<code javascript>
+(() => {
+  const format = { ext: "png", mime: "image/png", };
+  const video = document.querySelector("video");
+  const width = video.videoWidth;
+  const height = video.videoHeight;
+  const canvas = document.createElement("canvas");
+  canvas.width = width;
+  canvas.height = height;
+  const ctx = canvas.getContext("2d");
+  ctx.drawImage(video, 0, 0, width, height);
+  const timestamp = (new Date()).toISOString()
+    .replaceAll(/[t:]/gi, "-")
+    .replaceAll(/\..*$/gi, "");
+  canvas.toBlob((it) => {
+    const url = URL.createObjectURL(it);
+    const a = document.createElement("a");
+    a.href = url;
+    a.download = `screenshot-${timestamp}.${format.ext}`;
+    a.click();
+    URL.revokeObjectURL(url);
+  }, format.mime, 1);
+})();
+</code>
@@ Zeile 167: / Zeile 262: @@
     }
 });
-</code>
-==== backend ====
-=== hello world webserver (deno) ===
-<code javascript hello-world.ts>
-import { serve } from "https://deno.land/std@0.126.0/http/server.ts";
-const port = 80;
-const handler = (): Response => {
-    return new Response("Hello World!");
-};
-serve(handler, { port });
-console.log(`Listening on http://localhost:${port}`);
 </code>