examples/learning/helloworld64.html - master - githubmirror/pdf.js

examples/learning/helloworld64.html
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Calixte Denizet
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18 ноя 2025, 19:22
18 ноя 2025, 19:22b9368b5
<!doctype html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>'Hello, world!' base64 example</title>
  </head>
  <body>
    <h1>'Hello, world!' example</h1>

    <canvas id="the-canvas" style="border: 1px solid black; direction: ltr"></canvas>

    <script src="../../node_modules/pdfjs-dist/build/pdf.mjs" type="module"></script>

    <script id="script" type="module">
      // atob() is used to convert base64 encoded PDF to binary-like data.
      // (See also https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/
      // Base64_encoding_and_decoding.)
      var pdfData = atob(
        "JVBERi0xLjcKCjEgMCBvYmogICUgZW50cnkgcG9pbnQKPDwKICAvVHlwZSAvQ2F0YWxvZwog" +
          "IC9QYWdlcyAyIDAgUgo+PgplbmRvYmoKCjIgMCBvYmoKPDwKICAvVHlwZSAvUGFnZXMKICAv" +
          "TWVkaWFCb3ggWyAwIDAgMjAwIDIwMCBdCiAgL0NvdW50IDEKICAvS2lkcyBbIDMgMCBSIF0K" +
          "Pj4KZW5kb2JqCgozIDAgb2JqCjw8CiAgL1R5cGUgL1BhZ2UKICAvUGFyZW50IDIgMCBSCiAg" +
          "L1Jlc291cmNlcyA8PAogICAgL0ZvbnQgPDwKICAgICAgL0YxIDQgMCBSIAogICAgPj4KICA+" +
          "PgogIC9Db250ZW50cyA1IDAgUgo+PgplbmRvYmoKCjQgMCBvYmoKPDwKICAvVHlwZSAvRm9u" +
          "dAogIC9TdWJ0eXBlIC9UeXBlMQogIC9CYXNlRm9udCAvVGltZXMtUm9tYW4KPj4KZW5kb2Jq" +
          "Cgo1IDAgb2JqICAlIHBhZ2UgY29udGVudAo8PAogIC9MZW5ndGggNDQKPj4Kc3RyZWFtCkJU" +
          "CjcwIDUwIFRECi9GMSAxMiBUZgooSGVsbG8sIHdvcmxkISkgVGoKRVQKZW5kc3RyZWFtCmVu" +
          "ZG9iagoKeHJlZgowIDYKMDAwMDAwMDAwMCA2NTUzNSBmIAowMDAwMDAwMDEwIDAwMDAwIG4g" +
          "CjAwMDAwMDAwNzkgMDAwMDAgbiAKMDAwMDAwMDE3MyAwMDAwMCBuIAowMDAwMDAwMzAxIDAw" +
          "MDAwIG4gCjAwMDAwMDAzODAgMDAwMDAgbiAKdHJhaWxlcgo8PAogIC9TaXplIDYKICAvUm9v" +
          "dCAxIDAgUgo+PgpzdGFydHhyZWYKNDkyCiUlRU9G"
      );

      //
      // The workerSrc property shall be specified.
      //
      pdfjsLib.GlobalWorkerOptions.workerSrc = "../../node_modules/pdfjs-dist/build/pdf.worker.mjs";

      // Opening PDF by passing its binary data as a string. It is still preferable
      // to use Uint8Array, but string or array-like structure will work too.
      var loadingTask = pdfjsLib.getDocument({ data: pdfData });
      var pdf = await loadingTask.promise;
      // Fetch the first page.
      var page = await pdf.getPage(1);
      var scale = 1.5;
      var viewport = page.getViewport({ scale: scale });
      // Support HiDPI-screens.
      var outputScale = window.devicePixelRatio || 1;

      // Prepare canvas using PDF page dimensions.
      var canvas = document.getElementById("the-canvas");
      var context = canvas.getContext("2d");

      canvas.width = Math.floor(viewport.width * outputScale);
      canvas.height = Math.floor(viewport.height * outputScale);
      canvas.style.width = Math.floor(viewport.width) + "px";
      canvas.style.height = Math.floor(viewport.height) + "px";

      var transform = outputScale !== 1 ? [outputScale, 0, 0, outputScale, 0, 0] : null;

      // Render PDF page into canvas context.
      var renderContext = {
        canvasContext: context,
        transform,
        viewport,
      };
      page.render(renderContext);
    </script>

    <hr />
    <h2>JavaScript code:</h2>
    <pre id="code"></pre>
    <script>
      document.getElementById("code").textContent = document.getElementById("script").text;
    </script>
  </body>
</html>