Module: Dynamoid::Fields

Extended by:
ActiveSupport::Concern
Included in:
Components
Defined in:
lib/dynamoid/fields.rb

Overview

All fields on a Dynamoid::Document must be explicitly defined -- if you have fields in the database that are not specified with field, then they will be ignored.

Defined Under Namespace

Modules: ClassMethods

Instance Attribute Summary (collapse)

Instance Method Summary (collapse)

Instance Attribute Details

- (Object) attributes Also known as: raw_attributes

You can access the attributes of an object directly on its attributes method, which is by default an empty hash.



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# File 'lib/dynamoid/fields.rb', line 48

def attributes
  @attributes
end

Instance Method Details

- (Object) read_attribute(name) Also known as: []

Read an attribute from an object.

Parameters:

  • name (Symbol) —

    the name of the field

Since:

  • 0.2.0



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# File 'lib/dynamoid/fields.rb', line 77

def read_attribute(name)
  attributes[name.to_sym]
end

- (Object) update_attribute(attribute, value)

Update a single attribute, saving the object afterwards.

Parameters:

  • attribute (Symbol) —

    the attribute to update

  • value (Object) —

    the value to assign it

Since:

  • 0.2.0



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# File 'lib/dynamoid/fields.rb', line 98

def update_attribute(attribute, value)
  write_attribute(attribute, value)
  save
end

- (Object) update_attributes(attributes)

Updates multiple attibutes at once, saving the object once the updates are complete.

Parameters:

  • attributes (Hash) —

    a hash of attributes to update

Since:

  • 0.2.0



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# File 'lib/dynamoid/fields.rb', line 87

def update_attributes(attributes)
  attributes.each {|attribute, value| self.write_attribute(attribute, value)}
  save
end

- (Object) write_attribute(name, value) Also known as: []=

Write an attribute on the object. Also marks the previous value as dirty.

Parameters:

  • name (Symbol) —

    the name of the field

  • value (Object) —

    the value to assign to that field

Since:

  • 0.2.0



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# File 'lib/dynamoid/fields.rb', line 57

def write_attribute(name, value)
  if (size = value.to_s.size) > MAX_ITEM_SIZE
    Dynamoid.logger.warn "DynamoDB can't store items larger than #{MAX_ITEM_SIZE} and the #{name} field has a length of #{size}."
  end

  attribute_will_change!(name) unless self.read_attribute(name) == value

  if association = @associations[name]
    association.reset
  end

  attributes[name.to_sym] = value
end