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CacheViewer Continued, A History And Status Update ~ Wed, 06 Feb 2013 01:26:06 +0000

Update (2013-08-20):

The add-on discussed in this post has been discontinued.

End update.

A word of warning: this situation has me very upset. There will be strong language in this post.

As you may, or may not, know, I maintain a Firefox add-on named CacheViewer Continued. I did not originally author this add-on; it was originally developed by someone named "benki" as "CacheViewer." This add-on was extremely helpful when doing web development with Firefox. CacheViewer made it very easy to find all of the cached items for a given domain or of a given name. Not only that, but you could preview those items directly from the cache, delete them, or even save them elsewhere. So, CacheViewer was one of the add-ons I always installed in Firefox. Then came Firefox 4.0.

Firefox 4.0 broke CacheViewer in such a fashion that it wouldn't even load. I waited several weeks for an update, but benki seemed to have dropped off the planet. Making matters worse, there were no alternatives to CacheViewer (and there still aren't to my knowledge). So, I decided to look into the problem and see if I could correct it myself. It was a simple fix. Thus was CacheViewer Continued born and since May of 2011 I have been maintaining it as I am able (and is required).

Everything was working out well. I was releasing CacheViewer Continued into the "not fully tested" add-on repository, and people were happy. Then Mozilla noticed that people really liked CacheViewer and it was missing from the "fully reviewed" repository. As a result, Mozilla contacted me to see if I would be willing to submit CacheViewer Continued for full review so that people could install it directly from the browser add-ons tool. I said sure, even though I had planned to clean up the code before doing that. After a while, Mozilla started automatically bumping the supported version number in add-ons after an automated scan confirmed no problems with the next Firefox release. So it was really easy to "maintain" CacheViewer Continued -- I didn't have to do anything! Then they released Firefox 18.

With Firefox 18 they completely fucked CacheViewer Continued. First, I got the usual email after the automated add-on compatibility review. Whereas they normally consisted of "everything's cool, we've bumped the version compatibility number for you," this one resulted in a whole bunch of red text. Evidently, the guy that maintains the cache API upon which CacheViewer, and subsequently CacheViewer Continued, relied decided it would be cool to up and delete the god damn API. No warning whatsoever was sent to add-on developers; and there sure as hell wasn't a deprecation notice for at least one release of Firefox. Nope. It's just fucking gone!

Oh, and you remember that automated email I got about the problem? Yeah, they went ahead and automatically marked CacheViewer Contiued as compatible with Firefox 18 anyway. So that means everyone who uses CacheViewer Continued, almost 52,000 people, see no reason to hold off upgrading their browser. Let me summarize:

  1. Lot's of people love having CacheViewer Continued
  2. Mozilla breaks the API on which CacheViewer Continued relies without warning
  3. Mozilla tells people CacheViewer Continued will work anyway
  4. I'm fucked

Why am I fucked? The original CacheViewer was written under the assumption that the removed API will always exist. It relied on cache entries being able to be read in real-time. Thus, the code was not structured in such a way that it would be easy, or maybe even possible, to restructure into an asychronous model. Therefore, CacheViewer Continued requires a complete rewrite to solve the problem of the missing synchronous API. At the same time, I

  1. Haven't used Firefox full-time in at least a year, so the add-on has not been a priority for me
  2. Have been swamped at work so I can't devote any time to CacheViewer Continued there (where it does benefit me)
  3. Was in the middle of shopping for, and buying, a house

Yes, that's right, I don't use Firefox any longer. So why do I maintain an add-on for it? Because I know how useful CacheViewer Continued is to the people who do use Firefox (and know they need the add-on). As long as I am able, I cannot in good conscience leave these people hanging like benki did. But it is really fucking hard to so when when Mozilla does all they can to make it not worth my time. Keeping up with the god damn insane release schedule of Firefox was enough to drive me mad before they started automatically bumping the compatibility number. But now they're telling users the add-on will work after they tell me it won't? What the fuck? Even so, I have been working on the rewrite for a month.

The rewrite has not been easy. Like I said, I have a lot going on. But when I do get time to work on it, it's a slow process. The documentation for Mozilla's APIs is abysmal which results in a lot of digging just to figure out what I need, much less how to use it. The only saving grace is their new API specifically for add-on development. It is decently documented and has made it relatively easy to get up to the point where I am now -- something that lists cache entries, shows entry details, and loads cached images for preview from the original URL. But all of the advanced features, namely deleting and saving of entries and loading entries directly from the cache, requires digging through the poorly documented API and figuring out how to use it from within the new API.

I really wish I could provide you with a release date for something at least more usable than the "about:cache" page built into the browser, but I can't. I don't want to release something that is going to upset you, the user, even more than you already are. Please understand that I will make it available as soon as I can.

Update 07 February 2013:

I have submitted a very basic version (0.9.1) for review. Hopefully it will be available directly through the browser add-on manager within a day or so. In the meantime, you can download cacheviewer-continued-3e47cf8e944e.xpi from the BitBucket page.

CacheViewer Continued,  Software,  Technology


Todd said (2013-02-06 05:17:39 GMT):

Thank you much for your work on this!

Pezito said (2013-02-06 10:44:59 GMT):

Hi James,

first of all I'd like to thank you for CacheViewer Continued. It's a very useful add-on ; I was already using benki's version and after the Firefox 4.0 update, it was a relief to see the project maintained by someone else.

Now just like you've written it, I was taken by surprise when Firefox 18 was updated AND broke CacheViewer Continued (again...) without even an compatibility warning. I've been reading your updates on the add-on page with hope, and I understand they're giving you a hard time keeping this add-on working. Well, at least I'm gonna post here and thank you for it !

Good luck, I hope we'll hear from CacheViewer Continued soon. :)

James Sumners said (2013-02-07 21:24:41 GMT):

Thank you for the encouragement and kind words. It helps.

I'm posting this comment in case you have requested to be notified of new replies by email. I have submitted a new version for review. I have also added details to this post on how to go ahead and get it.

Josh said (2013-02-07 22:47:01 GMT):

Thanks for your great work with this essential add-on! I have to say you're something of a hero to the Firefox community.

Lisa said (2013-02-11 17:42:06 GMT):

After FF (self-)upgrade to 18.* nothing worked as I loved and I came here, removed 0.8 version and installed 0.9.1 instead: but I couldn't find a CVC menu item...maybe that was caused by any other plugin? So I felt f.... too, uninstalled FF 18, reinstalled FF 17 and CVC 0.8 and now I'm HAPPY :-). Thank you so much for your time and work and patience to provide such a useful plugin - I really HATE to browse without it! (My FF won't update until you've found the time to create a workaround...and if you don't, it will rest FF 17 in eternity.)

James Sumners said (2013-02-11 17:46:50 GMT):

Please read the "CacheViewer Continued is launched via a button, represented as a magnifying glass, in the add-on bar."

Adding the entry to the web developer menu is on the list of things that need to be done.

Ilari Halminen said (2013-02-13 12:22:08 GMT):


Nice to know what is happening with cache viewer. Especially I like your attitude to want upgrade the extension that you do no longer will need just because some people wants to use it! Your attitude is something that makes good for FOSS (in Open Source Society.)

For me seeing what is in the cache is a nice thing but nothing that I really need for anything. I mainly used it to examine the cache. Yes, I know there is still about:cache, but it is not so nice. I need to add that I have slow internet connection.

And I do all that mainly because I have some intrest in security, network performance (mainly because of the slow connection) and network errors.

I also have a personal question: What browser you do prefer / use instead of Firefox?

I have used many of those, just now I mainly use Iceweal (Fork of Firefox). I also use a lot Seamonkey. Just now I do not use t Firefox at all, but I like it.

Just some time ago I found Netsurf. It is nice, but lacks many features.

Google Chrome is nice, but using it feels like trading your life to Google. Opera is nice, and I use it sometimes, but lacks some features specially an option to select your file cache, that is vital for me.

I still want to thanks for making and updating that software.

Ilari H

DAPL said (2013-02-13 12:32:32 GMT):

I hear your justified pain, but there are many, many people out here that really appreciate your time and effort. I used to use it almost every day until release 18. Errrrrr.

James Sumners said (2013-02-13 13:27:06 GMT):

@Ilari: I use Chrome and Safari as my primary browsers. Firefox just can't seem to keep up with the number of tabs and windows that I keep open. It bogs down so much that clicking links is even slow.

Brian said (2013-02-15 23:49:00 GMT):

James --- Just wanted to verbalize the unspoken support you're no doubt getting from fans of CacheViewer Cont'd.

I had used Cache View (by Tim Johnson, not CacheViewer by Benki) with Firefox3 and Netscape for as long as I could. Now that FF3 is no longer getting it done, I've been forced to upgrade at least to FF12 and deal with the new cache format. That's where CVC comes in.

With your troubles of late, looks like you might think of naming your CVC rewrite for FF18, "CacheViewer-Continued-Continued".

Best of luck to you. We appreciate your efforts.

James Sumners said (2013-02-16 02:47:59 GMT):

@Brian, thank you. A complete rename wouldn't be a far fetched idea, but I'd rather people be able to find it and know what it is :)

Justino Figueiredo said (2013-02-24 19:42:11 GMT):

Thank you very much for your continued effort. It's most appreciated.

Ben Simpson said (2013-02-19 05:08:57 GMT):

Being a maintainer of anything is hard, so hats off to you. i'm shocked that Mozilla's automated tests for extension compatibility failed to pick up that removing the API your extension heavily relies on would cause it to fail. I wonder what they are really testing then? Even if it had detected problems, its still not a great solution without a software roadmap to give a heads up on deprecated components, and slower releases cycles.

Raymond said (2013-02-18 15:16:18 GMT):

Mr. Sumners, I used your viewer frequently and was very grateful to find it very easy to use. It was like discovering can-openers after years of opening cans with rocks or screwdrivers. A big relief! I simply wanted to let you know that here is one more person who looks forward with great eagerness to the day when we can employ your cache viewer again. I heartily agree with the others, your attitude has been commendable and something not often seen these days.

If the new release takes a day or two longer, so you can relax in your new home for a bit, well...okay.

Thank you.

D. Wallace said (2013-02-23 05:21:49 GMT):

Thanks for putting in all the work on CacheViewer.

To make it worth your while to do the rewrite how about setting up a donation site worked throught PayPal?

With 52,000 known users an average donation of $5 is a quarter million even an average of $1 get you $50,000.

Could help with the house.

James Sumners said (2013-02-23 20:44:07 GMT):

@D. Wallace: I used to have a PayPal donation button on this site. It was there for at least 5 years and I got one donation. And that was from a friend because I recommended a hosting provider to him.

When I was asked to submit for full review I considered ticking the "request donations" option. But I decided against it because I know that I can't afford to spend much time on this thing. If people are giving me their money because of the add-on, then I would feel more beholden to the users. I wouldn't want to take money for this thing and then not deliver up to expectations.

I appreciate the sentiment, though.

Ray Learmond said (2013-03-04 22:05:23 GMT):

James: Thanks a ton. One small problem - I downloaded the file from the BitBucket - I removed the old version from Firefox, re-opened Firefox, and dragged the file to the blank window - it appeared to install OK - clicked Tools, AddOns/Extensions - there it was. I then clicked Tools, Web Developer (where it was before) and it had not re-appeared - I could not find it anywhere. I am a newbie at this stuff - any ideas?

James Sumners said (2013-03-05 19:00:13 GMT):

@Ray, currently, it is only available via the add-on bar. Adding it back to the Web Developer menu is going to take a good bit more work. Hopefully I will be able to get to that soon, but making it available via the add-on bar allowed me to make a release.