Means of Abstraction

June 25, 2008

Today I was working on a Rails site where users have profiles that anyone can view, but if you are viewing your own profile, there are links on the page to edit various parts of the profile. I want the links to show up if you are viewing your own profile, but not be there if you are viewing someone else's profile. To implement this is trivial, as any Rails developer would tell you. I simply added a helper method:

def link_to_if_owner(title,url,options={})
  if current_user == @user
    link_to title, url, options

And changed the occurrences of <%= link_to "Edit", edit_something_path %> to <%= link_to_if_owner "Edit", edit_something_path %>. This probably took 15 seconds, and could not be more clear and succinct. When I compare this to doing Java/J2EE development, this task would probably have involved a custom JSP tag and would have been a complicated solution with much ceremony.

This is what is referred to as the means of abstraction in SICP. They assert that the power of a programming language or framework should be measured by its means of abstraction. The means of abstraction is how you take a set of operations and build a smaller operation that you can build on top of. This is just one example of many that shows why Ruby/Rails is a more powerful combination than Java/J2EE.

Posted in Technology | Tags J2EE, Ruby, Java, Rails

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