Monthly Archives: January 2010

Generating a plist file in rails

I recently wrote an iPhone app (Waiting for approval in the app store at the time of writing) that needed data exported from a website (recyclinggroupfinder.com). The simplest way of handling external data in an app it seems is using a plist file, so I wrote this to generate one for me.

First of all I made my action respond to the plist format:

Next I created a builder file to format the data:

Then register the MIME type at the bottom of environment.rb:

Mime::Type.register "text/plist", :plist

And that’s it! Well mostly. The XML file generated can be made significantly smaller by converting it into the binary plist format, run this on the command line in terminal after downloading the generated XML plist.

cat things_xml.plist | plutil -convert binary1 - -o things.plist

The resultant binary plist is almost half the size of the XML one, much better for inclusion in an iPhone app:

pleb:~ will$ ls -l things*
-rw-r--r-- 1 will will 1247300 20 Jan 18:50 things.plist
-rw-r--r--@ 1 will will 2110437 20 Jan 18:50 things_xml.plist

Of course it would be much better to generate the binary format directly, and the plist-official gem looks like it can handle that and I mean to investigate, but I wrote the XML version before finding the gem, and it works for me!

Edit: the plist_official gem seems to be gone, but check out the binary plist gem instead.

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Next NWRUG meeting 21st January – UNIX: Rediscovering the wheel

The original announcement is available on the NWRUG site.

This month John Leach of Brightbox will be talking on UNIX: Rediscovering the wheel.

“Those who don’t understand UNIX are condemned to reinvent it, poorly.”

We in the Ruby Community seem to have a habit of re-inventing things. Sometimes this is for good reason, but in some cases we don’t know we’re even doing it! We’re wasting valuable time that could be spent learning Erlang!

UNIX-like operating systems have been around for decades and lots of problems have come and gone in that time. I’m going to talk about some of the tools available that can be used to solve common Ruby and Rails deployment and development problems.

Brightbox will also be sponsoring the event so there will be pizzas available after the meeting in Odder across the road from the meeting.

Schedule

6:30pm :: Welcome & Pre-session bar visit.
7:00pm :: UNIX: Rediscovering the wheel by John Leach of Brightbox
7:45pm :: Pizzas at the Odder bar across the road sponsored by Brightbox

If you want more information email nwrug@willj.net, call Will on 07939 547 962 or tweet @will_j.

Sign Up

If you would like to attend this event please sign up here as the BBC need a list of attendees before the event, and I need to arrange the correct amount of food.

Location

This meeting is being held at one of our regular venues, the BBC Manchester main building on Oxford Road in central Manchester (Directions). If you get lost call Will on 07939 547 962.

Whenever a link on your website opens in a new window a panda cries

You’ve got a great website. It’s amazing. It’s so good no-one will want to leave it. Ever. Here’s what you’re thinking:

OMG wow. Our website is amazing. It’s so good no-one will want to leave it. Ever. Let’s help users enjoy our website forever by making all external links open in new windows so then they close the other websites our site will still be open. Our users will thank us until the end of time for making it easier to stay on our site, and anyway Marketing said we had to do it and they know the internet better than anyone!

Sad Panda

Oh dear. Most people don’t know this, but making external website links open in a new window makes pandas sad. Look, here’s a sad panda made sad because it used a website that opened external links in new windows.

Sad panda

Doesn't this panda look sad?

You did that, with your new window link opening. (Panda by sholt).

Why Pandas cry

You need to consider that your website is going to be just one part of a users browsing session. The user will probably already have open tabs in their current browser window and the tab they have your website in will probably have history before your site. When you force a new window to open for a user you are interrupting their browsing flow. When this happens the user has a jarring user experience because of your website. Well done your website.

There are already controls in browsers to let users open links in new windows or tabs, in Safari they are the the first two options in the right-click context menu, or a Cmd+click:

Browser controls already exist giving the user control over where links open

When you force the user to open links from your website in a new window you are taking away control the user already has.

It’s a PITA and I have to work around it

Here’s what I personally do when your website opens a link in a new window:

  1. Your website forces new window to open when I click on a link.
  2. New window opens, I close it immediately.
  3. On your website again I Cmd+click the link or right click and select ‘open in new tab’.
  4. I close the tab your website was in and re-position the new tab with the new website in where the tab for your website used to be.
  5. I mentally remove one karma point from your website in my internal website excellence tracker.

Look at the amount of messing around your website made me do. And now, because of this messing around, your website is no-longer accessible via my browser back button. You’ve succeeded in making your website even less accessible, the exact opposite of that you were trying to achieve.

Luckily I’m mentally tough much like Chuck Norris and so can take this two, maybe three times before cracking, but Pandas aren’t as tough as me. If this happened to a panda the panda would just cry. Sad.

Flushing memcached servers from Ruby

In Flushing memcached servers the easy way I highlighted a way to flush a memcached server without restarting it:

$ echo ”flush_all” | nc localhost 11211

However I almost never use the actual shell version of this, mostly I do the equivalent in Ruby by opening up a socket and communicating through that. Here’s a simple example:

socket = TCPSocket.new( '127.0.0.1', 11211 )
socket.write( "flush_allrn" )
result = socket.recv(2)
puts "Success!" if result == 'OK'
socket.close

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Carrot porn

Got this carrot in a bag, was most amused. Should probably try selling it on eBay.

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