Edge Rails Saves You Money (and improves performance)

James Stewart — Sun, 18 Feb 2007 01:04:30 +0000

For anyone who serves up content that is requested repeatedly by the same user agents (be they web browsers, news readers, or any other) it can quickly get expensive (financially and in performance hits) to use up bandwidth sending the same data to the same destination over and over. HTTP provides mechanisms to deal with that, but until recently they’ve been poorly supported.

Those costs are the reason that this is great news. DHH just committed a change to Edge Rails that automatically adds an ETag when sending a response and returns an HTTP 304 (Not Modified) when an agent comes back asking for the same content before it has changed.

Chad Fowler has a good explanation on his blog, where I heard the news, and this page from the Universal Feed Parser docs is also a good summary.

Rails’ Improved Join Model Creation

James Stewart — Sun, 20 Aug 2006 01:26:58 +0000

Jeremy Kemper has just checked in a change to Edge Rails that fixes my biggest frustration with has_many :through. Since it’s appearance a couple of versions back, has_many :through has been a great addition to the rails associations toolkit, making the use of join models infinitely cleaner. But until recently it was rather cumbersome to create those relationships.

For example, if I wanted to add an author to a book where the relationship is defined as:

has_many :authors, :through => :involvements, 
  :class_name => 'Contributor'

The simplest it could be to find and create an author and set up a link was:

book.involvements.create!(
  :author => Contributor.find_or_create_by_name(name))
book.authors(true)

Now it’s as simple as:

book.authors < < Contributor.find_or_create_by_name(name)

The one gotcha comes if your book object is a new record, and so doesn’t yet have an ID. Trying the above in that case will raise ActiveRecord::HasManyThroughCantAssociateNewRecords.

Since in my particular case I’m masking the association behind a proxy attribute, I considered getting around the problem by dynamically creating (and subsequently removing) after_save callbacks, but for now I’ve simply changed my controller to create the associations after the record is saved. Maybe Edge Rails will have some more options to offer us before long.

Thanks to Josh Susser for the original report. Check out his post for more detail and examples.

a work on process » edge rails

Edge Rails Saves You Money (and improves performance)

Rails’ Improved Join Model Creation