Failure to find instances of subclasses

[wmarbut]

Summary

When an instance of a subclass is created and none of the fields specific to that class are entered, the object cannot be queried

Situations where this is a problem

Some subclasses may only contain foreign key fields. For example, the Parent class in the prerequisites section could only contain the children field. This bug prevents the Parent class from being a persistable object.

Potential fix

I haven't really tested this and it is late for me, but this might work

Add this after line 153 of acts_as_cities.rb

        if (attributes_for_part_of.empty?) 
          attributes_for_part_of["id"] = self.id
        end

Prerequisites

Suppose the following classes

• Person
  • name (string)
  • birthday (datetime)
• Parent (extends Person)
  • children (foreign key)
  • can_yodel (int)
• Child (extends Person)
  • parents (foreign key)

Failure use-case

If you create a new parent object, but fail to set any attributes specific to the parent table, then It will not show up when queried

parent = Parent.new
parent.name = 'Shepherd Book'
parent.birthday = Time.now 
parent.save

When you try to query for this item, it is inaccessible

Parent.where(:name => 'Shepherd Book')

returns

 => [] 

Working use-case

When you create an instance of a subclass and use one or more of the fields specific to that subclass you can query for it

parent = Parent.new
parent.name = 'Shepherd Book'
parent.birthday = Time.now
parent.can_yodel = 1 
parent.save

returns

=> [#<Parent id: 1, type: "Parent", name: "Shepherd Book", birthday: "2012-01-03 05:00:00", can_yodel: 1>