In my spare time I’ve been learning Ruby on Rails. I’ve not been so excited about a web technology in a very long time. I’m really enjoying working on my projects with it and it’s the most productive I’ve ever been as a web developer. At some point I want to write a more detailed analysis on my thoughts, but in the meantime, here’s something I did that was kind of interesting that might be of use to somebody out there.

Rails by default has a number of helper methods that return simple HTML. One that’s extremely powerful is link_to which, generally speaking, generates links to other pages.

On one particular project, I knew I would be writing a lot of links that referenced another site. While I certainly could’ve written raw HTML since they weren’t using named routes or any other Rails niftiness and were essentially static links with a few dynamic URL variables, one of the principles of Rails is Don’t Repeat Yourself, so I wrote a custom link_to helper for the occasion.

In general, I knew all of my calls would be to the same domain, with varying pages and URL variables, ie:

http://www.constantsite.com/variable.cfm?urlvar1=dynamic&urlvar2=dynamic

Happily, Ruby hashes can easily be serialized as URL variables, and thanks to the ability of Ruby to merge hashes, I can even set a default target attribute that can be overridden later.

Here’s what I ended up with in my pages_helper.rb:

1 def link_to_mysite(text, page, urlvars={}, options={})
2   link_to text, "http://constantsite.com/#{page}.cfm?#{urlvars.to_query}", {:target => "_blank"}.merge(options)
3 end

And some sample usage:

1 link_to_mysite "No URL vars", "novar"
2 # renders: <a href="http://constantsite.com/novar.cfm?" target="_blank">No URL vars</a>
3 
4 link_to_mysite "Yeah!", "init", {:id => myvar}, {:class => "example"}
5 # renders: <a href="http://constantsite.com/init.cfm?id=<myvar contents>" class="example" target="_blank">Yeah!</a>
6 
7 link_to_mysite "No new window", "samewindow", {:id => myvar}, {:target=> "_self"}
8 # renders: <a href="http://constantsite.com/samewindow.cfm?id=<myvar contents>" target="_self">No new window</a>

Two little subtleties of the Ruby language at work here: 1. By using ={} on my last two arguments, they become optional, with the default being empty hashes.</li> 2. When merging two hashes, the keys from the argument to merge() override the keys from the object you call merge() on. That, combined with Ruby’s lovely habit of treating everything as an object, lets me declare my default :target (and any other future options) first, knowing it will be overridden automatically if the method is invoked with a specified :target.

Ruby is awesome - and Rails makes it even better.