Module: Ambry::Model::InstanceMethods

Defined in:
lib/ambry/model.rb

Instance Method Summary collapse

Instance Method Details

#<=>(instance) ⇒ Object

Ambry models implement the <=> method and mix in Comparable to provide sorting methods. This default implementation compares the result of #to_id. If the items being compared are not of the same kind.



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# File 'lib/ambry/model.rb', line 124

def <=>(instance)
  to_id <=> instance.to_id if instance.kind_of? self.class
end

#delete ⇒ Object

Tell the mapper to delete the data for this instance.



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# File 'lib/ambry/model.rb', line 164

def delete
  self.class.delete(self.to_id)
end

#id_changed? ⇒ Boolean

Returns true is the model’s id field has been updated.

Returns:

  • (Boolean) 


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# File 'lib/ambry/model.rb', line 136

def id_changed?
  to_id != @attributes[self.class.id_method]
end

#initialize(attributes = nil) {|_self| ... } ⇒ Object

Ambry models can be instantiated with a hash of attribures, a block, or both. If both a hash and block are given, then the values set inside the block will take precedence over those set in the hash.

Examples:

Person.new :name => "Joe"
Person.new {|p| p.name = "Joe"}
Person.new(params[:person]) {|p| p.age = 38}

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/ambry/model.rb', line 109

def initialize(attributes = nil, &block)
  @attributes = {}.freeze
  return unless attributes || block_given?
  if attributes
    self.class.attribute_names.each do |name|
      value = attributes[name] || attributes[name.to_s]
      send("#{name}=", value) if value
    end
  end
  yield self if block_given?
end

#inspect ⇒ Object 



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# File 'lib/ambry/model.rb', line 168

def inspect
  "#<#{self.class.name} #{self.class.attribute_names.map { |attr| "#{attr}: #{self.send(attr).inspect}" } * ', ' }>"
end

#save ⇒ Object

Tell the mapper to save the data for this model instance.



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# File 'lib/ambry/model.rb', line 149

def save
  self.class.mapper.put(self)
end

#to_hash ⇒ Object

Get a hash of the instance’s model attributes.



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# File 'lib/ambry/model.rb', line 129

def to_hash
  self.class.attribute_names.inject({}) do |hash, key|
    hash[key] = self.send(key); hash
  end
end

#to_id(use_old = false) ⇒ Object

Invoke the model’s id method to return this instance’s unique key. If true is passed, then the id will be read from the attributes hash rather than from an instance variable. This allows you to retrieve the old id, in the event that the id has been changed.



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# File 'lib/ambry/model.rb', line 144

def to_id(use_old = false)
  use_old ? @attributes[self.class.id_method] : send(self.class.id_method)
end

#update(attributes) ⇒ Object

Update this instance’s attributes and invoke #save.



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# File 'lib/ambry/model.rb', line 154

def update(attributes)
  HashProxy.with(attributes) do |proxy|
    self.class.attribute_names.each do |name|
      send("#{name}=", proxy[name]) if proxy.key?(name)
    end
  end
  save
end