Downloaded successfully dialog shows up even before download or download is canceled

[rhsakarpos]

https://github.com/opensds/multi-cloud/issues/864

[anvithks]

On clicking download button we read a stream of bytes and create the blob on the dashboard side. This blob is then saved by using the browsers save feature. This is where we are facinug the issue . We have to display the successfully downloaded message on saving the file to the file system. There is no way to know when the user has clicked on the save button and if the user clicks on the cancel button in the save dialog. Currently we are displaying a success message when the blob is successfully generated on the dashboard side after clicking on the download button.

[anvithks]

@rhsakarpos This is difficult to implement as there is no way to tap in to the browsers save dialog which is prompted to the user. We show the success message when the API call succeeds in fetching the file, but whether the user has saved it to the disk or not cannot be checked.