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Wikimedia Commons is a great project. Over 21 million freely licensed files speak a clear language. But, like all projects of such a magnitude, there are some issues that somewhat dampen the joy. The major source of conflict is the duality of Commons: on one hand, it is a stand-alone repository of free files; on the other hand, it is the central repository for files used on many other projects of the Wikimedia family, first and foremost Wikipedia. Some Wikipedias, the Spanish one for example, have completely deactivated local file storage and rely completely on Commons; others prefer Commons, but keep local file storage around for special cases, like the “fair use” files on English Wikipedia, and “Freedom of Panorama” images on German Wikipedia.

The ExCommons interface on the deletion page.

The interface on the deletion page.

Commons admins (myself among them, albeit more in a technical capacity) want the keep Commons “clean”, and remove non-free images. While this is only proper, it can lead to issues with the projects depending on Commons, when files that are used e.g. on Wikipedia get deleted on Commons. The issue becomes aggravated if the deletion appears to be “overzealous”; some admins interpret “only free images” as “there must not be a shadow of a doubt”. When files that are very likely to be free, and will (in all likelihood) never see a takedown notice from a third party, are deleted because of a vague feeling of unease, and thus vanish from a dozen Wikipedias without warning, it is bound to raise the ire of someone. Yet, Commons admins do have a point when they want to keep their project in excellent legal shape, no matter the consequences.

One of my most popular tools is the CommonsHelper, which helps to transfer suitable images from other projects to Commons. Today, I try to at least reduce the impact of happy-trigger-finger file deletions on Commons by throwing some tech at the admins there: I present ExCommons. It is a small JavaScript that reverses the direction of CommonsHelper: It can transfer files from Commons to other Wikimedia projects, using OAuth.

This is what an "evacuated" file looks like.

This is what an “evacuated” file looks like.

It presents as a list of projects that use the file; the list automatically loads on the special page for deletion (Commons admins can try it here; but don’t actually delete the image!).

  • Sites that use the file in one or more articles are marked in bold; other sites use the file in other namespaces, where a loss might not be as critical
  • Sites that are known to have local upload disabled are shown but unavailable
  • Sites that are known to allow a wider range of files and use the file in an article are automatically checked; others can be checked manually

If you have authorized OAuth file upload, you can click the “Copy file to selected wikis” button, and the tool will attempt to copy the file there. The upload will be done under your user name. A Commons deletion template will be removed to avoid confusion; a {{From Commons}} template will be added. I created that template for the English Wikipedia; it states that the file was deleted on Commons, that it might not be suitable on en.wp either, it has a No-Commons template to prevent re-uploading, a category for tracking etc.

For this tool to be permanently enabled, add the line

importScript('MediaWiki:ExCommons.js') ;

to your common.js page.

This tool should allow Commons admins to quickly and painlessly “rescue” files to Wikipedias that use them, prior to their deletion on Commons. It is said that social problems cannot be fixed by technology; but sometimes they can be alleviated.


  1. AndreasP wrote:

    Thank you very much. This tool was long overdue. Commons admins’ copyright paranoia is one of the main problems in the Wikiverse nowadays. I am glad I am no longer a part of this group of idiots (with very few exceptions, yourself included).

    Friday, July 4, 2014 at 08:19 | Permalink
  2. Pete Forsyth wrote:

    Excellent to have this tool, and thank you for the clear articulation of the problem it aims to alleviate. (Side note, this prompted me to look at Commons Helper for the first time since it moved to OAuth, which I had missed..I’ve begun cleaning up my old Wikipedia uploads. Thanks for that update too!)

    I think the cases where this tool can be uncontroversially applied will be a little tricky to find, for a few reasons — and persuading people to change established practices will always take a bit of work and time. But I’m taking it as a personal challenge to look for some opportunities to put it to use.

    Friday, July 4, 2014 at 18:12 | Permalink
  3. Pete Forsyth wrote:

    I found an opportunity for a small test, based on the following discussion: I think we encountered a bug — see below.

    Since this is a file that I mistakenly uploaded, and is not in wide use, it seemed like a good test case. I think even if it’s not PD, it could be used on enwp under a “non-free use rationale”, pursuant to that project’s exemption doctrine policy — so, not a trivial transfer that would just get deleted at the destination site.

    I was able to enlist the help of Steinsplitter, since I’m not a sysop on Commons. He installed the script, and then got to the Evacuator by manually entering the URL (if there’s a UI, we weren’t able to find it). But the result:

    “A file with name “P15exhibw.jpg” already exists in the shared file repository, and cannot be overwritten.”

    21:04:06 – Steinsplitter: the file is deleted but not transfaired \O/

    He also uploaded a screen shot:

    Friday, July 4, 2014 at 20:19 | Permalink
  4. Magnus wrote:

    Strange. I ran into that issue during testing, and thought I solved it. Maybe because I’m an admin on en.wp as well? All else failing, the image could always be transferred under a new name, though that would make for awkward editing…

    Friday, July 4, 2014 at 22:50 | Permalink
  5. Magnus wrote:

    Yup, that’s it. MediaWiki will not let you upload a file locally if the file exists on Commons, unless you are an admin on the local wiki. AAAARGH!

    Friday, July 4, 2014 at 22:53 | Permalink
  6. Pete Forsyth wrote:

    Oddly enough, it does seem to have created the enwp page in my name, but I think this was afterwards — I did not notice it happening at the time. (Though it’s possible I didn’t notice because it doesn’t really change anything easily observable…)

    I *think* it uploaded the file locally too, but honestly I’m not entirely sure — maybe it just created a local description page?

    Saturday, July 5, 2014 at 15:39 | Permalink
  7. Pete Forsyth wrote:

    Aha, I just read what you wrote more carefully — this must be because I’m an admin on enwp. But still — it didn’t complete the upload right away, I checked. So, very strange!

    Sunday, July 6, 2014 at 03:05 | Permalink
  8. Rillke wrote:

    Awesome! Your tools for transferring files have been always a big achievement and reduced workload of Commons users.

    Tuesday, July 8, 2014 at 12:07 | Permalink
  9. Pierre-Selim wrote:

    I’m really happy to have this tool at my disposal now.

    Monday, July 14, 2014 at 12:45 | Permalink
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    Thursday, July 24, 2014 at 14:16 | Permalink