Reading value from .yml file in controller

rubyonrails-talk
1

Hi    I have a controller open_service_desk and create action .Inside the action when create a ticket I need to get default values of some fields from a yml file say get_value.yml In that file I am storing values like ..(I dont know whether this the right way)..Why I am storing this is these are mandatory fields and I have set validation also these are not get from the user directly.

sd:   service_desk_status_id: 1   service_desk_category_id: 1   service_desk_sub_category_id: 1

            How can I read this in the action?

Thanks in advance Sijo

2

Assuming that your yaml file is in test/fixtures directory. Do something like this #say ticket is an object going to be created yml=File.open("#{RAILS_ROOT}/test/fixture/get_value.yml){|ym| YAML::load(ym) } ticket.service_desk_status_id=yml["sd"] ["service_desk_status_id"].to_i #assuming it to be integer ticket.service_desk_category_id=yml["sd"] ["service_desk_category_id"].to_i ticket.service_desk_sub_category_id=yml["sd"] ["service_desk_sub_category_id"].to_i

3

I was going to take a different tack. Assuming this isn't a test fixture but just a file that is being used from somewhere to set default values for new objects, then you could do:

  default_values=YAML.load_file('path/to/get_value.yml')

There are probably other ways to set defaults rather than loading up a file like this though.

You could embed them in a class method in the model and just pull them out when you need them. Or maybe apply them in a callback (http:// api.rubyonrails.org/classes/ActiveRecord/Callbacks.html) like before_create. Or use :default in your migration when defining the table - might not be appropriate doing this with id's though.

Callback example: class Foo < ActiveRecord::Base   before_create :apply_defaults

  private   def apply_defaults     self.field1='val1' if self.field1.blank?   end end

4

Hi Thanks for the reply.May I ask one more question? As Daniel Bush said this isn't a test fixture but just a file that is being used to set default values..So my question normally in which directory I can store this yml file whether inside models or view or anywhere?

You can store it anywhere you want really (although I'd just stick with letting the database handle default values)

Fred

5

I can't see the reason for using yaml like this - but I guess you have your reasons.

Since you're set on having your controller load up a yaml file every time it's accessed then I'd probably stick it in db/ somewhere. As Fred says, you could put it anywhere.

You could lazy load it to save hitting the file system every time:   class YourModel < ActiveRecord::Base     def YourModel.default_values       @@default_values ||= YAML.load_file(RAILS_ROOT+'/db/ get_value.yml')     end   end

6

You could create a constant in your ServiceDesk or OpenServiceDesk model (not sure how you've set your models up)...

class ServiceDesk < ActiveRecord::Base

  DEFAULTS = {:service_desk_status_id => 1, :service_desk_category_id => 1, :service_desk_sub_category_id => 1}

end

Then in your controller you could use yourobject.service_desk_status_id = DEFAULTS[:service_desk_status_id]

Perhaps there's a good argument against using a constant like this, I don't know, but to me it looks like a pretty simple way to do it.

Or, as Fred suggested, create a migration to make the DB handle the default values, like so:

change_column :tablename, :service_desk_status_id, :integer, :default => 1