vemod.net

Datorbutiker i Lund

Mon, 08 Mar 2010 23:09:34 +0100

Som en uppföljare till den populära Datorbutiker i Malmö-sidan finns nu här en lista för Lund.

Var vänlig och meddela mig om någon butik saknas.

Butiker i centrala Lund

Butiker lite varstans

Compliq

Butiker ute på Nova Lund

Cinematekets program i iCalendar-format

Fri, 12 Feb 2010 15:20:18 +0100

iCalendar (även kallat iCal) är ett standardiserat filformat för kalendrar som gör det möjligt att enkelt utbyta kalenderinformation mellan olika datorer (inkl. smartphones med kalenderfunktion). Cinemateket erbjuder inga iCalendar-filer för sina program själva så därför har jag genererat sådana filer.

Dessa kalendrar är senast uppdaterade för våren 2010:s program men innehåller tyvärr inte januaris filmer. Filmernas sluttid är inte korrekt utan jag har räknat med att varje film är 2 timmar lång. Kontakta gärna mig om du stöter på något problem.

Prenumerera på kalendern istället för att ladda ner den för att automatiskt få uppdateringar.

Malmö

Göteborg

Stockholm

Har just nu inget program.

Page Caching with Rails and Passenger

Tue, 19 Jan 2010 23:22:36 +0100

This page documents my favorite way of handling page caching with Rails and Passenger. It’s a simple and elegant technique if cache invalidation is infrequent and you can afford to sweep the entire cache once it happens. I’d appreciate any feedback on this article – just contact me.

Step 0: Start page caching

Use cache_page or caches_page in your controllers.

Step 1: Write cached files into `public/cache`

I don’t like polluting the public directory of my Rails applications with cache files so I dedicate a public/cache directory for them. Add this to your application configuration:

config.action_controller.page_cache_directory = "#{Rails.root}/public/cache"

Note: Replace Rails.root with RAILS_ROOT if you’re running an old version of Rails.

Step 2: Sweep your cache

class CacheSweeper < ActiveRecord::Observer
  observe YourModel, YourSuperModel

  def self.sweep_cache!
    pattern = "#{ActionController::Base.page_cache_directory}/**/*.html" 

    Dir.glob(pattern) do |filename|
      File.delete(filename)
    end
  end

  def after_save(*_)
    self.class.sweep_cache!
  end 

  def after_destroy(*_)
    self.class.sweep_cache!
  end 
end

Activate this observer with config.active_record.observers or invoke CacheSweeper.sweep_cache! yourself. Please note that it sweeps the entire cache.

Step 3: Configure Apache and Passenger

RailsAllowModRewrite On  
RewriteEngine On

RewriteCond %{THE_REQUEST} ^(GET|HEAD)
RewriteCond %{REQUEST_URI} ^/([^.]+)$
RewriteCond %{DOCUMENT_ROOT}/cache/%1.html -f
RewriteRule ^/[^.]+$ /cache/%1.html [QSA,L]

RewriteCond %{THE_REQUEST} ^(GET|HEAD)
RewriteCond %{DOCUMENT_ROOT}/cache/index.html -f
RewriteRule ^/$ /cache/index.html [QSA,L]

Use RewriteLogLevel and RewriteLog if you need to troubleshoot mod_rewrite.

Page History

2009-05-14: ActionController::Caching::Sweeper was replaced with ActiveRecord::Observer.

2009-05-16: The rewrite rules were revised after feedback from Jared Moody.

2009-08-28: Vince Wadhwani wrote and pointed out that the rules shouldn’t affect POST requests. Added an additional guard for that.

2009-10-04: Kevin Swope discovered that the last change, as implemented by me, effectively disabled the cache. Fixed by rearranging two lines.

2010-01-19: The stupid define_method stuff was replaced with plain methods.

Tags: Rails

How to Set Cache-Control for Rails Assets with Apache

Thu, 07 Jan 2010 00:20:20 +0100

RewriteCond "%{QUERY_STRING}" "[0-9]+$" 
RewriteRule "^.*$" "$0" [L,E=CACHE:True] # Match all.
Header onsuccess set "Cache-Control" "public, max-age=31536000" env=CACHE

Dependencies: mod_rewrite and mod_headers

Please contact me if you know an even nicer way.

Tags: Rails

Contact

Wed, 06 Jan 2010 23:17:59 +0100

Feel free to contact me (Christoffer Sawicki) if you have anything in your heart to disclose.

My e-mail, Jabber and Windows Live Messenger¹ address is christoffer.sawicki@gmail.com.

If you want to call me, you can find my phone number at the expected services on the web.

¹ Ugh, such a long name! I can hear the giggles at Microsoft’s marketing department – no wonder we call the service “MSN” over here. I understand that the employees need some entertainment while the ship that is Microsoft is sinking.

Christoffer Sawicki

Wed, 06 Jan 2010 23:15:14 +0100

Hello! My name is Christoffer Sawicki and this is my domain on the web. I live in the south of Sweden in the city of Lund where I practice Computer Science and Engineering-fu at LTH¹. I really enjoy instructing computers to do sophisticated things. Preferably while listening to music, mostly metal but also some post-rock and folk tunes. I also enjoy s-st-st-stuttering, drinking tea, collecting quotes and taking photographs.

Feel free to contact me if you want.

¹ The Faculty of Engineering at Lund University

My Shortwave Commands

Sat, 19 Dec 2009 15:22:53 +0100

Shortwave is a great service that keyword search-enables any JavaScript-capable web browser. (I use Shortwave instead of Keywurl for Safari because it has a much better UI and isn’t a hack.)

My Shortwave commands are available at http://vemod.net/misc/waves.txt. Copy what you like.

interactEither

Sun, 06 Dec 2009 00:37:02 +0100

interact is a very handy function, but it doesn’t handle computations that can fail. Here’s another convenience function that addresses that:

import System.IO
import System.Exit

interactEither :: Show a => (String -> Either a String) -> IO ()
interactEither  f = getContents >>= either (error . show) success . f
  where success x = hPutStrLn stdout x >> exitSuccess
        error   x = hPutStrLn stderr x >> exitFailure

Tags: Haskell

isInteger

Sun, 06 Dec 2009 00:31:57 +0100

A useful snippet:

import Text.Regex.Posix ((=~))

isInteger :: String -> Bool
isInteger = (=~ "^[0-9]+$")

Tags: Haskell

List of Static File CMSes

Sat, 05 Dec 2009 14:45:35 +0100

...with a rather wide meaning of the name CMS.

This list is supposed to be comprehensive, so please contact me if some system is missing.

vemod.net

Datorbutiker i Lund

Butiker i centrala Lund

Butiker lite varstans

Butiker ute på Nova Lund

Cinematekets program i iCalendar-format

Malmö

Göteborg

Stockholm

Page Caching with Rails and Passenger

Step 0: Start page caching

Step 1: Write cached files into `public/cache`

Step 2: Sweep your cache

Step 3: Configure Apache and Passenger

Page History

How to Set Cache-Control for Rails Assets with Apache

Contact

Christoffer Sawicki

My Shortwave Commands

interactEither

isInteger

List of Static File CMSes

Haskell Powered

Ruby Powered

Perl Powered

Python Powered

Thanks!

vemod.net

Datorbutiker i Lund

Butiker i centrala Lund

Butiker lite varstans

Butiker ute på Nova Lund

Cinematekets program i iCalendar-format

Malmö

Göteborg

Stockholm

Page Caching with Rails and Passenger

Step 0: Start page caching

Step 1: Write cached files into public/cache

Step 2: Sweep your cache

Step 3: Configure Apache and Passenger

Page History

How to Set Cache-Control for Rails Assets with Apache

Contact

Christoffer Sawicki

My Shortwave Commands

interactEither

isInteger

List of Static File CMSes

Haskell Powered

Ruby Powered

Perl Powered

Python Powered

Thanks!

Step 1: Write cached files into `public/cache`