Time Zones in Rails using Postgres

It appears that by default Rails creates it's timestamps in Postgres using timestamps without time zone information.  This means that if you're working directly with the database, using psql for example, and want to see local time representations you'll have to do something like this.

Specifically notice that I'm using the TIMEZONE function to re-cast the column to a timestamp with timezone.  Since the columns implied timezone is 'UTC' that's what's used.  Now that we have a timestamp with timezone we can convert that to local time using the "AT TIME ZONE" syntax.

More on Twitter Bootstrap in Rails

Yesterday I wrote about error handling in Rails while using Twitter Bootstrap.  One of the interesting things I was able to do with the custom form builder was move the active record attribute errors to the input fields they're associated with.  The example below is a bit simple but it should get the point across....

If you look at the template that created the form below you can see that that it doesn't include any special functionality.  All the work happens in the form builder.





If you look at the "text_field" method in the code below you can see that it just calls "input_wrapper" to add some html around the "text_field".  Since "input_wrapper" already had to test each active record attribute for errors so that it could add "error" to the classes of those elements it was pretty straight forward to tack an inline-help span on the end.





The code above is not elegant, it's just an experiment.  I certainly don't recommend using it as is but I wanted to share just in case some one is thinking about similar problems.


In general though I am fairly happy with the separation of concerns so far.  I think that by treating the multi-element fields bootstrap expects in it's forms as primitives I will be able keep my templates focused on the content and my presenters on the logic of the view.

Formatting Rails Errors for Twitter Bootstrap

I'm using Twitter's Bootstrap toolkit for the layout in a proof of concept application I'm working on.  So far my general impression is that I really like Bootstrap but there are a few obstacles to making it play nice with Rails.

One of those obstacles is that Rails formats fields with errors quite a bit differently than Bootstrap's CSS expects.  Below I describe a possible solution.  I'm not 100% sure this is the best approach but it seems to work well and I'm currently working on a proof of concept app that will be thrown out in several weeks so there's little risk if I'm wrong.

Rails default formatting looks like this...


Bootstrap's CSS expects this....


The solution I've arrived at is to first remove the "field_with_errors" div.  This is done by setting the field_error_proc to simply return the html passed in without wrapping it.


The next step was to create a FormBuilder subclass with the desired functionality.  The example below only demonstrates the 'text_field' method.  In practice I'll have to create a separate method for each Bootstrap form element I want to use in my application.


Then to use the custom form builder I'd do somthing like this....


I realize this wasn't exactly a detailed explanation of a solution but hopefully I managed to get the gist of the idea across.

Just Doing It!

Almost 18 months ago a had an an epiphany.  I'm not exactly sure what caused the thought to form but I know when it happened.  I'm certain I know when because I shared the idea in an email with a friend the moment the thought completed synthesizing it's self.

It's taken me a long time to put together a plan that I thought would let me execute on the idea sucessfully but I think I've finally gotten there.  Today, I'm shifting gears.  I'm no longer just thinking about the idea, I'm acting on it.

In fact I'm jumping in with both feet right now!

Simple EC2 Configuration

Over the last few years I've used different approaches to scripting the configuration of my EC2 servers. Recently I discarded a more sophisticated approach for a very simple system.  This is all pretty obvious and I'm sure you'll notice that I stole this directly from RVM but it's working out so well for me I feel compelled to share anyway.

I created a public repository of scripts on Github.  Then, like RVM, I take advantage of the fact that Github allows access to the raw content of the master branch through a fixed url.  This allows me to execute commands like the one below which will run my script for installing the Passenger gem and Apache module:

sudo su -c "bash < <(curl -s https://raw.github.com/mgreenly/aws/master/shared/passenger.sh)" -

Then I combine that with a strict set of conventions; for example I always use Ubuntu so all of my scripts assume they are being executed as the ubuntu user.  This can make some of the scripts a bit tougher to write, for example when you have to sudo su to become postgres to execute database commands, but it makes it easy to execute one script after another in a chain right from your initial login.

This approach may not compare to using tools like Chef or Puppet but I'm finding I really like the simplicity of it.

EC2 Friendly SSH Config

If you spend lots of time in EC2 or any other cloud service your going to collect tons of junk in your $HOME/.ssh/known_hosts file. If you're remapping domain names to cloud based servers and those IPs change SSH's default settings will prevent you from connecting until the conflict is fixed. Instead of constantly having to edit known_hosts a better approach is to have SSH ignore known_hosts while you work in the cloud.

Here's my $HOME/.ssh/config. In addition to ignoring known_hosts I also set the identiy key file and the default user.

Host *compute-1.amazonaws.com
User ubuntu
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
IdentityFile ~/.ssh/your-ec2-key
ServerAliveInterval 30
ServerAliveCountMax 120

With these settings I can copy the DNS name straight from the AWS console, type 'ssh ' at the command line, paste the DNS name and then connect; example:

ssh ec2-107-100-123-99.compute-1.amazonaws.com

Unity fucking blows! Gnome Shell has potential.

The title may be flame bait but hopefully this will help some fence sitters in their evaluation of Unity and Gnome Shell.

The most significant factor in my statement above is that I think the Gnome Shell developers realized there needed to be a stronger context switch between using applications and managing them. In Gnome Shell when you bring up the launcher or the desktop switcher all of the applications fall away from focus and tile in the center of the screen so that the launcher and desktop switcher can be exposed. At first I found this behavior a bit distracting and figured it was all eye candy but after a while I realized just how brilliant it was.

In Unity the context switch isn't as significant. The launcher comes into view when you need it and hides when you don't. In theory anyway. In reality it's a frustrating game of whack-o-mole. The launcher is never there when you want it and it's always in the way when you don't.

It seems the Gnome developers had a much better grasp of the basic user experience issue at hand. By design or intuition they better understood that you manage applications in a different context than you use them and there was benefit in making that separation more distinct not less.

Gnome Shell certainly has room for improvement but the amount of change required to make it great is significantly less than Unity will need.

Almost a full year no posts!

I'm not at all sure what I'm going to do with this space.

Tomorrow would have been an entire year with no posts if it hadn't been for this one.

I have been posting on Google+ quite a bit but that's certainly no substitute for a blog.

I'm also a bit conflicted about how to focus my energy. Do I post here in a personal space? Or on a blog for my business under my name?

Oh well, when I get it figured out I'll definitely share here.

a lot but I really should blog it and link it there since the Google+ posts fade with time. On the other hand I've consideree

Basic Git Configuration

I recently purchased a new machine and had to configure Git again. The email/user setup it reminds you of but I couldn't remember how to configure color output without some digging. So I decided to share it here just in case anyone else may find it useful.

Browser Profile Backup

While I was trying to configure a specific user profile for a Selenium testing today I accidentally deleted my Firefox profile. At first I thought no big deal, my lap top (the machine I was using), is regularly backed up to an external USB drive attached to the docking station. Unfortunately for some strange reason I chose to exclude the $HOME/.mozilla/ directory that contains the profile.

I use Delicious for bookmarks so it mostly just means re-populating my tools bars and resetting passwords on rarely used sites if I can't remember them, not all that big of a deal really.

Still, I couldn't help but notice how much more I depend on the browser than desktop applications these days.