Adapter specific date handling in Rails
Thursday, May 15th, 2008Lately I’ve had to endure working on a Rails project where the requirements dictate the use of Microsoft SQL Server as the choice database. In addition, we’ve had to test environments consisting of Microsoft Windows/Apache 2.2/Mongrel and Red Hat/Apache 2.2/Mongrel with various adapter(odbc, oledb) and tabular data stream translators. When testing several operating systems, adapters, manipulators, etc there were inevitable issues between the different setups. One of the most common issues was the adapter specific handling of dates. Depending on the adapter’s TDS(tabular data stream), dates can be returned as strings or date objects. This issue made our project less flexible as we were having to modify view code here and there. To solve the issue we extended the rails core and created a DBI override class in the lib directory of our project.
To do this, add a core_ext folder inside of your project’s lib directory. Next, add a ruby file called core_ext.rb; contents shown below.
#Include each of the files in the core_ext directory
Dir[File.dirname(__FILE__) + "/core_ext/*.rb"].each{ |file| require(file) }
Once your core_ext folder and file are setup in lib you’ll need to tell the environment.rb file to include your core extenders. Append the following line to your environment.rb file.
require 'core_ext'
Once our extensions are visible in the environment we can add our date time handler for dates where DBI is the project adapter. Add a file called DBI.rb in the core_ext directory. Contents shown below.
require "date"
module DBI
class Date
def to_friendly_str(options = {})
t = self.to_time
t.to_friendly_str(options) rescue self
end
def strftime(options = {})
t = self.to_time
t.strftime(options) rescue self
end
end
end
You’ll notice a non-standard method called “to_friendly_str”. You can replace this with stftime or create a custom date string handler like we did. I’ve added to_friendly_str below if you want to add it to the core_ext directory in addition to the DBI module or you can place it in your application controller. Enjoy!
def to_friendly_str(options = {})
# Attempt to init a new time object
# from this string then call
# to friendly_str on it.
t = Time.parse(self)
t.to_friendly_str(options) rescue self
end