# Suggestion: uncacheable tag

**URL:** <https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380>\
**Category:** Radiant CMS\
**Created:** [July 22, 2006, 4:08am UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380 "2006-07-22T04:08:42Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 22, 2006, 4:08am UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/1 "2006-07-22T04:08:42Z")

</div>

Some pages, such as a Google sitemap, need to be generated dynamically  
with each view, and never cached. It’d be nice to be able to mark them  
as such, rather than manually going and clearing the cache before  
regenerating it.

Similarly: A navigation plugin might need to be regenerated when -any-  
page is saved, not just when the particular page it’s used on is  
regenerated. I’m not sure if there’s a clean way to deal with that  
right now, or what the best solution is - maybe a “depends-on-world” tag  
which, if present, expires this snippet whenever any other response is  
expired?

Jay L.

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 22, 2006, 4:39am UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/2 "2006-07-22T04:39:32Z")

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Jay L. wrote:

> Some pages, such as a Google sitemap, need to be generated dynamically  
> with each view, and never cached. It’d be nice to be able to mark them  
> as such, rather than manually going and clearing the cache before  
> regenerating it.

I’ve considered it, and haven’t ruled it out, but it’s fairly easy to do  
with a behavior:

class UncacheableBehavior \< Behavior::Base  
register “Uncacheable”

```
 def cache_page?
   false
 end

```

end

> Similarly: A navigation plugin might need to be regenerated when -any-  
> page is saved, not just when the particular page it’s used on is  
> regenerated. I’m not sure if there’s a clean way to deal with that  
> right now, or what the best solution is - maybe a “depends-on-world” tag  
> which, if present, expires this snippet whenever any other response is  
> expired?

Editing a snippet or layout will invalidate the entire cache.

–  
John L.  
[http://wiseheartdesign.com](http://wiseheartdesign.com)

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 22, 2006, 4:15pm UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/3 "2006-07-22T16:15:15Z")

</div>

John W. Long wrote:

> class UncacheableBehavior \< Behavior::Base  
> register “Uncacheable”
> 
> ```
> def cache_page?
> false
> end
> 
> ```
> 
> end

Perfect. I don’t think there’s any reason for a tag, then - anything  
that’s going to be dynamic is going to involve code, and thus it can do  
that.

> > Similarly: A navigation plugin might need to be regenerated when -any-  
> > page is saved, not just when the particular page it’s used on is  
> > regenerated. I’m not sure if there’s a clean way to deal with that  
> > right now, or what the best solution is - maybe a “depends-on-world” tag  
> > which, if present, expires this snippet whenever any other response is  
> > expired?
> 
> Editing a snippet or layout will invalidate the entire cache.

Ah, but the problem is that if I edit a page somewhere else - say, I  
change the title - the navigation snippet now needs to be regenerated,  
but it doesn’t know that, because I didn’t edit it.

Jay

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 22, 2006, 9:56pm UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/4 "2006-07-22T21:56:42Z")

</div>

Jay L. wrote:

> John W. Long wrote:
> 
> > Editing a snippet or layout will invalidate the entire cache.
> 
> Ah, but the problem is that if I edit a page somewhere else - say, I  
> change the title - the navigation snippet now needs to be regenerated,  
> but it doesn’t know that, because I didn’t edit it.

But this is only a problem for a maximum of 5 min. As that is the length  
of time a page is allowed to remain in the cache. Is that sufficient for  
your needs?

–  
John L.  
[http://wiseheartdesign.com](http://wiseheartdesign.com)

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 23, 2006, 12:35am UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/5 "2006-07-23T00:35:57Z")

</div>

Jay L. wrote:

> John W. Long wrote:
> 
> > But this is only a problem for a maximum of 5 min. As that is the length  
> > of time a page is allowed to remain in the cache. Is that sufficient for  
> > your needs?
> 
> For mine personally, sure - I’m running a low-traffic site with 20  
> pages. I imagine larger sites might use a longer expire\_time, though  
> that does push this suggestion into YAGNI-yet territory.

I’m not getting that kind of traffic on my own sites. And if you are I’m  
sure you can afford to build your own content management system. 🙂

There are all kinds of things that you can do when you get to that level  
though. Use Apache to cache the site with mod\_proxy, do load balancing,  
etc… So assuming you haven’t built your own system at that point, you  
have options.

Jason Hoffman was doing some testing on Radiant recently. He was getting  
some pretty impressive stats:

[http://forum.textdrive.com/viewtopic.php?pid=96828#p96828](http://forum.textdrive.com/viewtopic.php?pid=96828#p96828)

I actually find this quite funny as I have done very little optimization  
on Radiant. It just proves that the method used for caching static pages  
was sound.

–  
John L.  
[http://wiseheartdesign.com](http://wiseheartdesign.com)

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 22, 2006, 11:06pm UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/6 "2006-07-22T23:06:59Z")

</div>

John W. Long wrote:

> Jay L. wrote:
> 
> > John W. Long wrote:
> > 
> > > Editing a snippet or layout will invalidate the entire cache.  
> > > Ah, but the problem is that if I edit a page somewhere else - say, I  
> > > change the title - the navigation snippet now needs to be regenerated,  
> > > but it doesn’t know that, because I didn’t edit it.
> 
> But this is only a problem for a maximum of 5 min. As that is the length  
> of time a page is allowed to remain in the cache. Is that sufficient for  
> your needs?

For mine personally, sure - I’m running a low-traffic site with 20  
pages. I imagine larger sites might use a longer expire\_time, though  
that does push this suggestion into YAGNI-yet territory.

Jay

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 23, 2006, 5:43pm UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/7 "2006-07-23T17:43:24Z")

</div>

John W. Long wrote:

> John W. Long wrote:
> 
> > I actually find this quite funny as I have done very little optimization  
> > on Radiant. It just proves that the method used for caching static pages  
> > was sound.
> 
> There are a couple of pictures in his photo stream that feature Radiant.  
> I found this one impressive:
> 
> [7 million on radiant behind a BIG-IP: throughput, connecti… | Flickr](http://flickr.com/photos/textdriveinc/179393665/in/photostream/)

Wow. OK, clearly I’m using old-school thinking on new-school hardware.  
I was already thinking about how someday, Radiant would need a more  
complex caching scheme, with snippet caching and dependency trees and  
whatnot so the whole cache doesn’t need invalidation…

but YAGNI.

Cool.

Jay

---

<div class="post-metadata">

**Author:** ![jay-levitt](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@jay-levitt](https://www.ruby-forum.com/u/jay-levitt)\
**Post date:** [July 23, 2006, 12:39am UTC](https://www.ruby-forum.com/t/suggestion-uncacheable-tag/99380/8 "2006-07-23T00:39:21Z")

</div>

John W. Long wrote:

> I actually find this quite funny as I have done very little optimization  
> on Radiant. It just proves that the method used for caching static pages  
> was sound.

There are a couple of pictures in his photo stream that feature Radiant.  
I found this one impressive:

[http://flickr.com/photos/textdriveinc/179393665/in/photostream/](http://flickr.com/photos/textdriveinc/179393665/in/photostream/)

–  
John L.  
[http://wiseheartdesign.com](http://wiseheartdesign.com)