WebToAppMaker

JavaScript Bridge

Downloading Files from JavaScript

Send an explicit authenticated download request to the native in-app downloader.

Before you start

  • File Downloader enabled
  • A downloadable URL or data source

Configure and verify

  1. Prepare the URL

    Use a short-lived HTTPS URL when possible.

  2. Add optional metadata

    Pass filename, MIME type, referrer, and short-lived request headers in the options object.

  3. Start the download

    Call webtoapp.downloadFile(url, options) from a user action.

  4. Let native UI report progress

    The configured panel shows status and completion actions. Test cancellation and opening the saved file.

Example

webtoapp.downloadFile(reportUrl, {
  filename: "annual-report.pdf",
  mimeType: "application/pdf",
  headers: { Authorization: "Bearer " + shortLivedToken }
});

Security

Test before release

  • URL uses HTTPS
  • Token expires quickly
  • Filename and MIME type are correct
  • Cancel and open were tested