Class: Entity

Inherits:
Object
  • Object
show all
Defined in:
lib/og/entity/clone.rb

Class Method Summary collapse

Class Method Details

.clone(source, *args) ⇒ Object

Clones an object in every possible way (cannot copy HasMany but can copy all others - BelongsTo, etc). Provide a source object as first arguments, the rest (if any) are passed along to the initialize constructor when calling new to make the copied object.



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# File 'lib/og/entity/clone.rb', line 88

def clone(source,*args)
  destination = source.class.new(*args)
  copy_properties(source, destination, [], false)
  # Must save here to copy join tables.      
  destination.save!
  copy_relations(source, destination, [])
  destination.save!
  destination
end

.copy_equal_relations(source, destination, ignore = []) ⇒ Object 



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# File 'lib/og/entity/clone.rb', line 64

def copy_equal_relations(source, destination, ignore = [])
  source.class.relations.reject{|r| not [Og::JoinsMany, Og::ManyToMany].include?(r.class)}.each do |relation|
    next if relation.name == nil or ignore.include?(relation.name)
    source.send(relation.name).each do |related|
      destination.send(relation.name).send(:<<, related)
    end
  end
end

.copy_inferior_relations(source, destination, ignore = []) ⇒ Object

Copies relations of one record to another. Only copies has_one, refers_to, belongs_to relationships as has_many requires modifying of other objects and cannot be copied (by design). If you think you need to copy these relations, what you need is a joins_many relationship which can be copied.



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# File 'lib/og/entity/clone.rb', line 45

def copy_inferior_relations(source, destination, ignore = [])
  real_ignore = Array.new
  
  # Map relation symbols to foreign keys.
  
  ignore.each do |symbol|
     source.class.relations.reject{|r| [Og::JoinsMany, Og::ManyToMany, Og::HasMany].include?(r.class)}.each do |relation|
       if relation.name == symbol.to_s
         real_ignore << relation.foreign_key.to_sym
         break
       end
     end
  end      
  
  # Use instance variable property copier method.
  
  property_copier(source, destination, real_ignore, false, true)
end

.copy_properties(source, destination, ignore = [], use_setter_method = false) ⇒ Object

Accepts source object, destination and ignore. Source and destination are self explanatory; ignore is a list of properties not to copy (i.e. :create_time,:update_time). By default sets the class variables directly on the remote model instance, if you set use_setter_method to true, uses create_time= style copying tactics,



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# File 'lib/og/entity/clone.rb', line 34

def copy_properties(source, destination, ignore = [], use_setter_method = false)
  property_copier(source, destination, ignore, use_setter_method, false)
end

.copy_relations(source, destination, ignore = []) ⇒ Object

Copies all relations except HasMany which is impossible to copy. Use a JoinsMany relation instead if you need a copyable HasMany (which is irrational).



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# File 'lib/og/entity/clone.rb', line 77

def copy_relations(source, destination, ignore = [])
  copy_inferior_relations(source, destination, ignore)
  copy_equal_relations(source, destination, ignore)
end

.property_copier(source, destination, ignore, use_setter_method, relations) ⇒ Object

Does the work of clone_properties and copy_inferior_relations. Syntax is the same with one extra field to tell the routine what it is copying.



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# File 'lib/og/entity/clone.rb', line 102

def property_copier(source,destination,ignore,use_setter_method,relations)
  primary_key_symbol = source.class.primary_key.symbol
  source.class.properties.to_a.each do |symbol, property|
    next if primary_key_symbol == symbol or ignore.include?(symbol) or
     (relations and not property.relation) or (not relations and property.relation)
     
    variable = "@#{symbol}"
    if use_setter_method
      destination.send("#{symbol}=".to_sym,source.instance_variable_get(variable))
    else      
      destination.instance_variable_set(variable, source.instance_variable_get(variable))        
    end
  end
end