59 lines
1.8 KiB
Ruby
59 lines
1.8 KiB
Ruby
class Version < ActiveRecord::Base
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belongs_to :item, :polymorphic => true
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validates_presence_of :event
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def reify
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unless object.nil?
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attrs = YAML::load object
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# Normally a polymorphic belongs_to relationship allows us
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# to get the object we belong to by calling, in this case,
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# +item+. However this returns nil if +item+ has been
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# destroyed, and we need to be able to retrieve destroyed
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# objects.
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#
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# In this situation we constantize the +item_type+ to get hold of
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# the class...except when the stored object's attributes
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# include a +type+ key. If this is the case, the object
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# we belong to is using single table inheritance and the
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# +item_type+ will be the base class, not the actual subclass.
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# If +type+ is present but empty, the class is the base class.
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if item
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model = item
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else
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class_name = attrs['type'].blank? ? item_type : attrs['type']
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klass = class_name.constantize
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model = klass.new
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end
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attrs.each do |k, v|
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begin
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model.send "#{k}=", v
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rescue NoMethodError
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logger.warn "Attribute #{k} does not exist on #{item_type} (Version id: #{id})."
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end
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end
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model.version = self
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model
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end
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end
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def next
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Version.first :conditions => ["id > ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
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:order => 'id ASC'
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end
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def previous
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Version.first :conditions => ["id < ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
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:order => 'id DESC'
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end
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def index
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Version.all(:conditions => ["item_type = ? AND item_id = ?", item_type, item_id],
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:order => 'id ASC').index(self)
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end
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end
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