Show HN: A Chrome extension that prevents duplicate downloads

Can't wait to try this out. Some of the course files on my university's website are in .docx format instead of .pdf and I always forget I've downloaded them before, so by the end of the semester I end up with 7 copies of the same file.

As an aside, one of the problems I've had with certain Chrome Extensions is that the Chrome Webstore is telling me that "This application is not supported on this computer. Installation has been disabled." I started noticing this when I upgraded to Win 8 from my Win 7, and when I looked it up it was something about NPAPI plugins being disabled for Chrome on Windows 8. However this [1] and [2] make it seem that this is only for Chrome in metro mode, but I've been getting this message in Desktop mode as well. Now I don't know anything about Chrome extensions and file system access, but it would be great if it can be coded using some other kind of plugin. There is a workaround for Chrome/Win8 [3] but it does require a bit of work and it will put people off from installing it if they have to jump through those hoops.

[1] (https://groups.google.com/forum/#!topic/tincr-for-chrome-dev...)

[2] (http://blog.chromium.org/2012/07/npapi-plug-ins-in-windows-8...)

[3] ()http://blog.chromium.org/2012/07/npapi-plug-ins-in-windows-8...

Re: Show HN: A Chrome extension that prevents duplicate downloads

#5

Post by yefim323 » Sun, Mar 31, 2013, 5:06 PM UTC

alexsb92 wrote: post #4

Can't wait to try this out. Some of the course files on my university's website are in .docx format instead of .pdf and I always forget I've downloaded them before, so by the end of the semester I end up with 7 copies of the same file. As an aside, one of the problems I've had with certain Chrome Extensions is that the Chrome Webstore is telling me that "This application is not supported on this computer. Installatio…

I apologize for the lack of support. Chrome's download API (https://developer.chrome.com/dev/extensions/downloads.html) is very flaky and has just been added full support in Chrome 27.0.1448.0 dev-m according to http://stackoverflow.com/questions/15451313/closed-uncaught-...

Re: Show HN: A Chrome extension that prevents duplicate downloads

#6

Post by quasque » Sun, Mar 31, 2013, 5:14 PM UTC

It's a good idea, but downloading something from the same URL (or filename fragment from an URL) does not necessarily imply that it's a duplicate. Would be interesting to see something similar to this extension that uses attributes sent at the start of an HTTP response - e.g. entity tag or content length - for duplicate checking.

Re: Show HN: A Chrome extension that prevents duplicate downloads

#7

Post by yefim323 » Sun, Mar 31, 2013, 5:18 PM UTC

quasque wrote: post #6

It's a good idea, but downloading something from the same URL (or filename fragment from an URL) does not necessarily imply that it's a duplicate. Would be interesting to see something similar to this extension that uses attributes sent at the start of an HTTP response - e.g. entity tag or content length - for duplicate checking.

I was thinking of also checking for the same file size. Would that improve the accuracy of detecting duplicates?

Re: Show HN: A Chrome extension that prevents duplicate downloads

#8

Post by alexsb92 » Sun, Mar 31, 2013, 5:22 PM UTC

yefim323 wrote: post #5

alexsb92 wrote: post #4

Can't wait to try this out. Some of the course files on my university's website are in .docx format instead of .pdf and I always forget I've downloaded them before, so by the end of the semester I end up with 7 copies of the same file. As an aside, one of the problems I've had with certain Chrome Extensions is that the Chrome Webstore is telling me that "This application is not supported on this computer. Installatio…

I apologize for the lack of support. Chrome's download API ( https://developer.chrome.com/dev/extensions/downloads.html ) is very flaky and has just been added full support in Chrome 27.0.1448.0 dev-m according to http://stackoverflow.com/questions/15451313/closed-uncaught-...

Oh don't worry about it. Kinda saw it coming as I had that problem before. And that's great! Been meaning to switch to the dev channel for a while now.

Re: Show HN: A Chrome extension that prevents duplicate downloads

#9

Post by yefim323 » Sun, Mar 31, 2013, 5:22 PM UTC

gailees wrote: post #3

What's the point? I don't mind downloading it right there again at all...

It's a passive way of notifying you that you already have this file on disk. You can resume the download if you want to keep the second file.

Re: Show HN: A Chrome extension that prevents duplicate downloads

#10

Post by anigbrowl » Sun, Mar 31, 2013, 5:36 PM UTC

yefim323 wrote: post #5

alexsb92 wrote: post #4

Can't wait to try this out. Some of the course files on my university's website are in .docx format instead of .pdf and I always forget I've downloaded them before, so by the end of the semester I end up with 7 copies of the same file. As an aside, one of the problems I've had with certain Chrome Extensions is that the Chrome Webstore is telling me that "This application is not supported on this computer. Installatio…

I apologize for the lack of support. Chrome's download API ( https://developer.chrome.com/dev/extensions/downloads.html ) is very flaky and has just been added full support in Chrome 27.0.1448.0 dev-m according to http://stackoverflow.com/questions/15451313/closed-uncaught-...

Ah, that explains a lot. This looks useful because I often have an itchy trigger finger and download more than one copy. But you know what I really miss in Chrome would be a decent download manager that lets me select multiple files from one page instead of DLing them one at a time. Last time I looked the only extension for this practically announced itself as malware.