Question

Does ruby or rails provide a method to order strings in a specified order? Say that I have the following priorities “Severe, High, Medium, Low”.

These priorities are not going to change frequently (if at all). I have a Task model with a priority column:

tasks
  - id (integer)
  - name (string)
  - priority (string)

I’d like to get an array of all the tasks ordered by priority. Since the logical order does not follow alphabetical order, it’s not possible to simply order by the priority column:

Task.all(:order => :priority)

What I’ve done is create a Priority model and defined the associations: Task belongs_to Priority. In the priorities table, I then assigned each priority name a value and ordered by that value. Is there a better way to do this? I’d rather not have a priorities table at all and declare a PRIORITY constant (as a hash), or simply specify the priority as a string in the tasks table.

Answer 1

Switch to a integer like Aaron said, then you will probably want to use a default_scope.

For example:

class Task < ActiveRecord::Base
  default_scope :order => 'tasks.position' # assuming the column name is position
  ...

With a default scope you won’t have to specify the sort order in any of your find method calls – the tasks will automatically be sorted.