ZIP Download

This page explains how download() bundles conversion results into a ZIP and triggers a browser download, and how filename templates work.

Flow

1. When file is null / undefined, it resolves undefined immediately without converting or downloading
2. When there are no results yet, it first runs await this.convert(); existing results are reused without re-rendering
3. Appends the progress overlay to <body> and adds every image to JSZip as base64
4. Builds the ZIP with generateAsync({ type: "blob", streamFiles: true }), syncing compression progress to the overlay
5. Creates an <a download> pointing at URL.createObjectURL(blob), then after 500ms resolves, clicks it, and removes the link and the overlay

<button id="save">Download sample.zip</button>
<script>
  document.getElementById("save").addEventListener("click", async e => {
    e.target.disabled = true;
    const buffer = await (await fetch("/assets/sample.pdf")).arrayBuffer();
    const converter = new pdf2image({ file: buffer, filename: "sample.pdf yyyy-MM-DD", type: "png", scale: 0.5 });
    try {
      await converter.download();
      console.log("downloaded", converter.images.length, "images");
    } catch (err) {
      console.log("failed:", String(err));
    }
    e.target.disabled = false;
  });
  new pdf2image({}).download().then(result => console.log("no file ->", String(result)));
</script>

Filename Template

At construction filename is trimmed and its first .pdf is removed (case-sensitive, anywhere in the string). At download time these date tokens are replaced with local time:

Output Names

Notes:

• The image extension comes straight from type; with type: "jpg" the extension is .jpg but the content is PNG (see Conversion)
• Without filename, the ZIP is named .zip and images get names that start with a space, such as 0.jpg
• Image indexes follow the result array order, which is not guaranteed to match page order

Failure Behavior

The Object URL created by download() is never passed to revokeObjectURL, so repeated downloads on one page stay in memory until the page closes.

Related Pages

• Progress Overlay
• Methods and Properties