de tomKronieken

Soms vraag ik mij af hoe de wereld werkte, vroeger. Je weet wel, voor het internet bestond.  En voor 'gsm' een woord was. Het vreemde is: ik was er toen al, ik heb dat meegemaakt. Een wereld zonder TV, nee, dat niet, maar internet en gsm? Ik heb het grootste deel van mijn leven zonder meegemaakt. En toch kan ik het me niet meer voor de geest halen, hoe dat was. Vreemd.

Sometimes, you want to change behaviour of a method, depending on who the caller is. An example might be to throw an exception if the caller is a class you don't know. You want to make the method protected, but for some reason, you can't put all the callers in the same package as the callee. In C++, you have the concept of 'friend', where a callee can define which callers are allowed. Or so it exists in my memory, but that doesn't matter. To achieve the same thing in Java, you can inspect the stacktrace: public boolean isFriend() { new Exception().getStackTrace()[2].getClassName().startsWith(MY_PACKAGE_NAME); } And use it as follows:

public void something() { if (!isFriend()) { throw new NotFriendException(); else { // do nifty stuff here } }

Now, while this works, I have a sneaky suspicion that this isn't the most performant solution: creating a stacktrace is said to be an expensive operation. But it's useful once in a while.

• LiquidRail: ZiYa Plugin - Charting the rails...
  ZiYa is based on the most excellent XML/Swf charts charting tool. It allows you to render charts in your web app by leveraging Flash rendering. No worries mate, you won't need to learn Flash to use this plugin.
  (tags: rails ruby web)

• Apple - Pro - Mac OS X Tips
  (tags: macosx)

It's Javapolis again! I'll be there Wednesday and Thursday, and I'll be the guy not wearing the official Javapolis t-shirt ;-)

• Kalenders synchroniseren — Michel Vuijlsteke's Weblog

Well, it made me smile.

Serge:

Dus als er iemand zocht naar een business idea…. je hebt al zeker één klant :-)

Wie wil? Wie wil? Straks krijg ik zelf nog zin ;-)

• Internet Fax - Fax Service for Home or Office
  fax over the web

Toen ik Peters euforische aankondiging las, dacht ik even dat Dupuis eindelijk met een online winkel gestart was. Helaas. Om een strip te bemachtigen, moet je je blijkbaar nog altijd naar een baksteen-en-cementen gebouw begeven. Hoe zou dat eigenlijk komen, dat de Azurs en de Proxissen van deze wereld geen strips aanbieden? Mijn Visa-kaart zou alleszins snel getrokken zijn.

• HTML Playground, html, css reference by example
  (tags: css)
• There is no spoon, why the best software design and development process is all in your head
  "high performing design teams might not follow a consistent process at all"
  (tags: software)

• Velakor Feeds at Velakor Software
  (tags: rails ruby rss)
• 24 ways: An Explanation of Ems
  Finally, somebody who actually explains what an em is ...
  (tags: css)

Andrew chimes in on "That whole shutdown debate". In fact, I have the opposite use case: when I close the lid of my laptop, I generally don't want it to go to sleep. For starters, it takes way too long for my laptop to wake back up. My working place is often the living room, where I'm surrounded by 3 toddlers. When I get up to get a pacifier, it is not an option to keep the laptop open on the coffee table -- imagine toddles who start to hit a keyboard whenever they see one. So I close the lid. But I don't want to wait longer for my (windows) laptop to wake back up than I have time spent getting the pacifier. Second, my laptop gets backed up at night. So I just leave the thing running. A lit screen is unnecessary at that time, so I close the lid. And it can't go to sleep, because the "scheduled task" will not run then. So. Can you come up with even more scenarios to have all those options available? ;-)

• kuler
  colorpicker
  (tags: Color)

• Gliffy.com - Create and share diagrams online.
  Draw & share diagrams on the web
  (tags: web)
• Welcome to ScheduleWorld
  ScheduleWorld calendars, contacts, tasks and notes.
  (tags: web)