Yup, It uses the browser's memory to transfer files.
Until browser apps can be given permission to access the file system, this will be yhe case.
Until browser apps can be given permission to access the file system, this will be yhe case.
Spec: https://www.w3.org/TR/FileAPI/
MDN: https://developer.mozilla.org/en-US/docs/Web/API/File_and_Di...
>The API doesn't give you access to the local file system, nor is the sandbox really a section of the file system. Instead, it is a virtualized file system that looks like a full-fledged file system to the web app. It does not necessarily have a relationship to the local file system outside the browser.
>What this means is that a web app and a desktop app cannot share the same file at the same time. The API does not let your web app reach outside the browser to files that desktop apps can also work on. You can, however, export a file from a web app to a desktop app. For example, you can use the File API, create a blob, redirect an iframe to the blob, and invoke the download manager.
Is it possible to "see" from JavaScript whether or not the download manager has downloaded the file completely, so that the file can be removed from FileAPI storage?
Unfortunately, this is a non-standard API implemented only by Chrome. You have to use other APIs like IndexedDB and WebSQL (also deprecated and non-standard) to get a working solution in all browsers.
This deficiency is really holding back the web.
You can then use idb.filesystem.js to add api support for firefox etc. Search the file above for "is_chrome" for a few idb.filesystem.js-specific quirks.
Looking at that page, it looks like firefox will ship with support in version 50?