Question

I am developing an app that needs to send text messages, so I have carrier information stored in a database. I also need that information in an XML file for client side code to read. To make this happen, I am writing a script that reads the carrier information from the DB and creates an XML file in the config directory. I felt this script would fit best in lib/tasks.

I need to access the database from this script, but I want to use some object to access it. If I use

db = Mysql.new('domain', 'username', 'password', 'database') 

I will have to keep multiple versions for different environments because I do not use MySQL all the time. That would be very sloppy. I am sure there is a way to do this. I tried to just access the object…this is what I have so far:

RAILS_HOME = File.expand_path(File.join(File.dirname(__FILE__),'../..')) RAILS_CONFIG = '#{RAILS_HOME}/config'  f = File.new('#{RAILS_CONFIG}/mls_widget_config.xml', 'w') carriers = Carrier.find_all f.write carriers f.close 

But Carrier is not defined, which makes sense. How can I give this script access to the the Carrier object in the DB?

Also as a side, if anyone knows how to easily convert what I read from the DB into proper XML that would be great. I was going to write something custom real quick.

Thank you!

Answer 1

You can enable a Rake task to access your models by defining your task like this:

task :my_task => :environment do   # Task code end 

Note the => :environment, which grants this access. You can then instruct your Rake task to use different environments this way:

rake RAILS_ENV=development my_task rake RAILS_ENV=production my_task 

As for XML serialization, you can use the built-in to_xml method, such as:

Carrier.all.to_xml 

Note that the method .all is a recent addition to Rails, and is an alias for .find(:all).