See also Browser.StartDownload().

In CEF 3 downloads are handled automatically if ApplicationSettings.downloads_enabled is set to True (default). A default SaveAs file dialog provided by OS is displayed. If the download is aborted by user LoadHandler.OnLoadError will get called with errorCode ERR_ABORTED.

There is no download progress available. If you need such feature you will have to create a custom implementation of downloads. It would need to be investigated which callbacks from client handlers would allow for such implementation. Take a look at RequestHandler.OnBeforeBrowse, OnBeforeResourceLoad, and/or ResourceHandler.

On Linux there is a bug and ERR_ABORTED is reported even for successful downloads. See the comments in the wxpython.py example.

A download handler with callbacks like OnBeforeDownload and OnDownloadUpdated may be exposed to CEF Python in the future.

See RequestHandler.GetDownloadHandler().

You must keep a strong reference to the DownloadHandler object while downloading, otherwise it gets destroyed and the DownloadHandler callbacks won't be called.

The callbacks of the DownloadHandler class will always be called on the UI thread.

An example DownloadHandler can be found in the wxpython.py script.

bool OnData(str data)

A portion of the file contents have been received. This method will be called multiple times until the download is complete. Return |True| to continue receiving data and |False| to cancel.

void OnComplete()

The download is complete.