Here’s a before and after shot:

I think it’s much better, definitely more modern and minimalist.

The new blog theme is basically a heavily modified version of the
wonderful and free Compositio WordPress theme –
you can check out a demo of Compositio here to see how different it is.

The only thing I kept from my old theme, which I affectionately called “Clover”, was the same clover logo. I did that with the shape tool in Photoshop – it’s a simple logo and no skill was required to create it, obviously!

If you’re reading this in a feed reader or one of those aggreggator-type sites, you can help me out by checking out the blog itself and giving me some good old constructive criticism.

I attributed it to the recent jailbreak (I’ve already removed the jailbreak trying to figure out this problem) at first. I only realized something was really wrong when the iPhone’s battery started draining while it was charging via USB!

Looking around on teh interwebs, I managed to solve it (easily!) by following the suggestions from this thread at the Apple support forums. Here’s what worked for me:

1. Go to Settings on your iPhone.
2. Turn Notifications off. I’m not sure if this is necessary but did so just in case.
3. Go to Mail, Contacts, Calendars and delete all your accounts (I deleted even Calendar accounts just in case). You may want to write down or backup your account settings first.
4. Go to Fetch New Data (also in the same Mail, Contacts, Calendars settings) and make sure Push is Off.
5. It’s probably not necessary but you may want to restart your iPhone (power it on and off) here.
6. Add back all your accounts. You can turn Push back on Fetch New Data now.
7. You can also turn Notifications back on if you wish.

It seems like the iPhone 3.0 OS update has a bug where email accounts with active push notifications were set to keep fetching new email even if push is turned off explicitly. Hopefully this post will help solve your battery problems, if not, you’ve gotta keep looking – the Apple iPhone Support forums is a good place to start.

It probably sounds like shameless self-promotion that I’m blogging about these changes since I’d contributed them. Well, yeah that’s true, but I’m also doing so because I doubt these changes will ever be made known since Curb doesn’t publicize any updates or changelogs.

Curb is my current number 1 HTTP client for Ruby so the more love it gets, the better.

Passing cookies as a string in Curb requests

Curl veterans will probably know how to do this with the curl binary:

curl -b "auth=abcdef; ASP.NET_SessionId=lotsatext;" example.com

This sends a request to example.com with 2 cookies named “auth” and “ASP.NET_SessionId” (I hate those big-ass ASP.NET cookies btw). There wasn’t a way to set this in Curb, so I looked up the libcurl C API docs and replicated the same option in Curb (commit on Github). An example:

curl = Curl::Easy.new('http://example.com/')
curl.cookies = 'auth=abcdef; ASP.NET_SessionId=big-wall-of-text;'
curl.perform

Of course, the cookies will more often be retrieved/constructed rather than a literal like in the example above. In my case, I was proxying cookies while trying to wrap an API around a site that doesn’t have one.

Passing cookies as a file via the “cookiefile” option

The second change is the new cookiefile option. This replicates curl commands like these:

curl -b cookies-to-send.txt www.example.com

with something like this in ruby:

curl = Curl::Easy.new('http://example.com/')
curl.cookiefile = '/path/to/cookies-to-send.txt'
curl.perform

The cookies file looks like this (you can get a sample with the --cookie-jar option to curl, e.g. curl --cookie-jar cookies.txt www.wego.com):

www.wego.com	FALSE	/	FALSE	0	lang
www.wego.com	FALSE	/	FALSE	0	user_country_code	SG

Check out the commit on Github if you’re interested.

Why would I use these?

Now you might be wondering how these 2 changes are useful – well, they are totally irrelevant to you if you’re not expecting any cookie support in Curb. However, if you’re accessing or scraping a site that uses cookie-based authentication, these changes allow you to keep your Curb client authenticated across sessions, even when doing HTTP POSTs (Curb doesn’t send cookies properly in POST requests even if curl.enable_cookies is set).

I’ve found these changes to Curb particularly useful since I vastly prefer Curb to most HTTP clients for its speed and lightweight implementation, and heavier scraper-type HTTP clients like Mechanize are a last resort.

So anyway, I am one of those laggards and only wrote a Rails Metal piece not too long ago for a Rails app on Wego.com in an effort to optimize some high volume requests. It looked something like this:

class Adamantine
  def self.call(env)
    if env['PATH_INFO'] =~ ROUTE_REGEX
      location = Location.find(1) # Use ActiveRecord.

      [200, { 'Content-Type' => 'text/html' }, [location.to_json]]
    else
      # Leave it to Rails to deal with the request.
      [404, { 'Content-Type' => 'text/html' }, ['Not Found']]
    end
  end
end

Notice the use of an ActiveRecord model. It ran for quite awhile, almost 30 minutes, in production until I started getting notification emails about “Too many open database connections” to the MySQL server! The change was promptly rolled back and there was no cheezburger for me.

As it turns out, Rails doesn’t take care of certain things in Rails Metal pieces, including the releasing of connections back to the database connection pool. A bit of googling turned up this bug in Rails’ bug tracker (see Josh Peek’s comment about ActiveRecord::Base.clear_active_connections!).

I rewrote the Rails Metal piece to always ensure it clears any active database connections with ActiveRecord::Base.clear_active_connections!:

class Adamantine
  def self.call(env)
    if env['PATH_INFO'] =~ ROUTE_REGEX
      location = Location.find(1)

      [200, { 'Content-Type' => 'text/html' }, [location.to_json]]
    else
      # Leave it to Rails to deal with the request.
      [404, { 'Content-Type' => 'text/html' }, ['Not Found']]
    end
  ensure
    # Release the connections back to the pool.
    ActiveRecord::Base.clear_active_connections!
  end
end

Moral of the story: Don’t forget to release your database connections if you’re using ActiveRecord in your Rails Metal. Or even better, don’t use ActiveRecord in Rails Metal – you’re aiming for raw speed anyway right?

If you belong to what I imagine must be now the microscopic population of loyal readers of my blog, please do hook up with me on FriendFeed or Twitter. I’ll follow you back if you’re a reader!

This tab tearing capability is a pretty neat feature – I know you can already do this in Safari, Opera and Galeon. It’s really well done in Safari, which I think is what Firefox is emulating. Nice to see Firefox follow suit!

If you can’t wait for Firefox 3.1, try it out in a recent Firefox nighty build (remember to use a new profile unless you are willing to risk corrupting your daily profile).

Here’s what you can do:

1. Go to about:config in Firefox.
2. Type in “session” in the “Filter” box.
3. Edit browser.sessionhistory.max_entries – this is the number of pages stored in the history of your browsing session. Basically these are pages that can be reached using your Back and Forward buttons. The default is 50 – I reduced it to 20.
4. Edit browser.sessionhistory.max_total_viewers – this is the number of pages that are stored in RAM so that they aren’t re-processed by Firefox’s rendering engine. This is what allows you to go Back to a page in Firefox and have it load almost instantaneously. The number of pages stored actually depends on the amount of RAM on your machine (see this). I reduced this to 4 (I have 2GB RAM).
5. Edit browser.sessionstore.max_tabs_undo – the number of tabs you can restore after closing them (you can do this with Ctrl/Cmd-Shift-T). The default of 10 is more than I really need, so I reduced it to 3 tabs.
6. Edit browser.sessionstore.interval – Firefox saves your session after every 10 seconds by default. I changed this to a more conservative 30000 milliseconds.

You can read more about these preferences and more at the MozillaZine Knowledge Base. If you’ve any tips on how to improve Firefox’s performance, be sure to share!

But we were attached to our ugly shade of green to leave those pages in their naked glory. Preliminary CSI work told me that some cached stylesheets generated by Rails were empty files. Why is this is happening?

stylesheet_link_tag and the :cache option

Was I overriding the stylesheets generated by Rails in different pages? Because we have a lot of cobranded sites and country sites on wego.com, I use the :cache option when using stylesheet_link_tag very often.

For example, the main wego.com site’s layout template has a stylesheet_link_tag like this (in reality there are a whole lot more stylesheets):

<%= stylesheet_link_tag 'yui/reset-fonts', 'search',  :cache => 'cache/search/listings' %>

When I need to make a new page for a cobranded site, I’ll create a new layout template with this:

<%= stylesheet_link_tag 'yui/reset-fonts', 'search', "sites/#{current_site}/cobrand", :cache => "cache/#{current_site}/search/listings" %>

Oftentimes I’d copy and paste (boo and hiss all you want!) the stylesheet_link_tag from one layout template to another and forget to update the cache path (the :cache => '/path/to/stylesheet' part). Two different stylesheet sets being cached to the same path is naturally a very stupid thing to do. So this wasn’t it, but it’s good to point this out because I have made this mistake at least 2 times!

Don’t check in generated CSS files by accident

Next, since I was using Sass, I was by now pretty sure that was it. First things first: did I check in a generated CSS file into source control (we use Git)? It’s another amateur mistake, but unsurprisingly, I’ve done this a couple of times. I think I’d wasted about an hour hunting down the reason for a style change that just wouldn’t show up. Yeah, I could have just added *.css to .gitignore, but I’m still using a mix of pure CSS and Sass templates.

The problem

In the end, I found this blog post by Ari Lerner on the CitrusByte blog about similar woes with Sass in production that set me on the path to a solution. It seems that when Rails encounters stylesheet_link_tag calls, it starts to pull together all the stylesheets and sometimes Sass is unable to generate the CSS files fast enough. Rails then throws an exception about not being able to find the CSS files and outputs an empty CSS file to the cache path.

The solution

The solution? Generate all the CSS files from Sass templates prior to restarting Rails when deploying. I added a rake task for updating all the Sass stylesheets:

namespace :sass do
  desc 'Updates stylesheets if necessary from their Sass templates.'
  task :update => :environment do
    Sass::Plugin.update_stylesheets
  end
end

Then, I created a mirror of this as a Capistrano task:

namespace :sass do
  desc 'Updates the stylesheets generated by Sass'
  task :update, :roles => :app do
    invoke_command "cd #{latest_release}; RAILS_ENV=#{rails_env} rake sass:update"
  end

  # Generate all the stylesheets manually (from their Sass templates) before each restart.
  before 'deploy:restart', 'sass:update'
end

Now, whenever I do a cap deploy, the stylesheets are generated before the Rails processes are restarted, ensuring that Rails’ stylesheet_link_tag helper is always able to find the pure CSS files when trying to merge them together and caching them to a single file.

Anyway, if you hold down the Cmd key (aka the Apple key), a menu pops up that shows the folder hierarchy of where the currently opened QuickTime movie is in your filesystem:

This works in all Mac apps that display the filename of the currently open/focused file in the titlebar.

It’s useful for me since my NADD means I try to close as many unused windows as possible to adhere to my Cmd-Tab diet – now I can close Finder windows after opening files and be sure that I can get back to them quickly. What about QuickSilver? Yup, I do use (and love) QuickSilver but I don’t let it catalog every single file!

Another nice thing about this is that I can easily reveal files in Finder in my favorite text editor (TextMate) without needing to use the project drawer:

Catch the new first edition – this one’s about the API changes since Rails 2.1.

Here’s a shot of Portland Convention Center where it’s all happening:

There’re queues for collection of badges after registering your attendance:

Patience in the queue rewarded me with a RailsConf badge/name tag:

I was at the Meta-programming Ruby for Fun & Profit tutorial in the morning. I think when I selected the tutorial it was before I’d seen Neal Ford and Patrick Farley’s (the speakers) presentation videos from elsewhere – I know Patrick presented at MWRC and enjoyed that video.

So anyway, after the break I went over to the Refactoring Your Rails Application tutorial. Was pretty good, but I didn’t learn much I didn’t already know.

Lunch came in the form of a pretty box:

After lunch was the 2nd tutorial session and I went to both CI for the Rails Guy (or Gal) (by Chad Woolley) and Developer Testing Tricks (by Brian Takita). There were some scathing comments about how the tutorials were rather underwhelming so far in #railsconf on IRC. While I agree that the tutorials were rather underwhelming, I think I should have expected it. Oh well, I’ll know to skip them next time.

Later that night, at the Birds of a Feather session, after stealing a Pivotal Labs t-shirt (they’re launching a bug tracker, project management type app called Pivotal Tracker at RailsConf), Yehuda Katz (Merb and jQuery ninja) gave a presentation on Merb (geared towards Rails folks). It was a pretty interesting talk though there wasn’t much above what Ezra had presented previously at GoRuCo 2008 and at MWRC 2008 (I think Yehuda did one too but I can’t remember where now). Yehuda pointed out a (heated) discussion that happened recently on keeping Merb syntax as Rails-friendly as possible. I have no objection against a different syntax really, especially since Merb looks pretty well-documented in the source itself – would be nice if someone could point out an up-to-date Merb tutorial though.

Anyway, that’s it from me – as always, if anyone who reads my blog recognizes me at RailsConf, do say hi (#railsconf works too).

I’ll be at (my first) Railsconf 2008 in Portland, Oregon this Thursday onwards – if anyone sees me and recognizes me from my Facebook picture please come and say hi (no head butting though).

This week’s report covers changes from 19th May 2008 to 25th May 2008 (the day the corresponding Rails Envy podcast was recorded).

first and last methods now work with associations and named_scope

Remember how the merging of the has_finder gem into Rails allowed you to do things like Post.first and Post.last?

Now you can go one step further and use the same methods on your ActiveRecord associations. For example:

post = Post.find(1)
first_comment = post.comments.first

If you have a named_scope named recent defined, you can even do this:

post.comments.recent.last

This neat little enhancement is courtesy of Ryan Bates (yes, that Ryan Bates of Railscasts fame).

Related changeset: http://github.com/rails/rails/commit/73c59638549686fccc749ffd3ac53cb533c5fd61

Cache stores now have an exist? method and controllers get fragment_exist?

The cache stores in Rails (Memcache, file stores, etc.) now have an exist? method that checks whether a cached value exists given a cache key. This allows Rails controllers to expose a fragment_exist?
method that allows you to check for existence of a cache fragment:

fragment_exist?('example.com/foo/bar')

This little enhancement is courtesy of José Valim.

Related changeset: http://github.com/rails/rails/commit/99860b72aebe0348f41e82d4710343498d89a84b#diff-2

Create association records with block argument

You can now create records for associations like so:

post.coments.create!(:title => 'Techcrunch') do |c|
  c.body = "Rails can't scale"
end

This is in keeping with the ActiveRecord::Base.create change previously mentioned.

Credit for this patch goes (once again) to Ryan Bates.

Related changeset: http://github.com/rails/rails/commit/6cba97d2a449faf21aec9fe9d4434067e414226f

As always, let me know of any suggestions or how I can improve the Living on the Edge (of Rails) series.

This week’s report covers changes from 12th May 2008 to 18th May 2008 (the day the corresponding Rails Envy podcast was recorded).

caches_action can has conditionals

caches_action now takes an :if option (just like caches_page does). For example:

caches_action :index, :if => Proc.new { |c| !c.request.format.json? }

This little enhancement is courtesy of José Valim.

Related changeset: http://github.com/rails/rails/commit/7708650f73ddb4db300ea2059c60c1d907a4384e

Bugfix: :select option is now scanned in ActiveRecord finders to ensure needed tables are included in generated SQL

Post.find(:all, :include => :author, :select => 'posts.*, authors.id as "author_id"', :limit => 2)

Would generate an SQL statement like this:

SELECT posts.*, authors.id as "author_id" FROM "posts" LIMIT 2

Notice how the authors table is not joined. This oversight is now fixed.

Thanks go to John Devine for this bugfix.

Related changeset: http://github.com/rails/rails/commit/b28b54cab090bed8f099ef375b419a8f92390dd4

As always, let me know of any suggestions or how I can improve the Living on the Edge (of Rails) series. Also, if anyone has any recommendations of (non-ruby-related) things to do in Portland, do let me know!

• You can specify the user you want to use to login to your gateway server like so: set :gateway, 'deploy@deploy.example.com'. This logs in to your gateway server as the “deploy” user.
• You can specify an alternate SSH port for both your gateway and your deployment servers. E.g. setting ssh_options[:port] = 11111 will make Capistrano SSH to your gateway server with on port 11111. For your actual application (and web and database) servers, you can specify the SSH port like so:

  set :gateway, 'deploy@deploy.example.com'
  role :app, '192.168.1.113:22222'
  role :web, '192.168.1.113:22222'
  role :db,  '192.168.1.113:22222', :primary => true

• If you’re using public key authentication, you should put the public keys of your users (those who be deploying your app) on the gateway server and on the actual servers. I thought Capistrano would use the key of the “deploy” user but nope.