Class: Dynamoid::TransactionWrite::UpdateFields

Inherits:
Base
  • Object
show all
Defined in:
lib/dynamoid/transaction_write/update_fields.rb

Defined Under Namespace

Classes: UpdateRequestBuilder

Instance Method Summary collapse

Constructor Details

#initialize(model_class, hash_key, range_key, attributes, &block) ⇒ UpdateFields

Returns a new instance of UpdateFields.



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 9

def initialize(model_class, hash_key, range_key, attributes, &block)
  super()

  @model_class = model_class
  @hash_key = hash_key
  @range_key = range_key
  @attributes = attributes || {}
  @block = block
end

Instance Method Details

#aborted? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 33

def aborted?
  false
end

#action_request ⇒ Object 



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 45

def action_request
  builder = UpdateRequestBuilder.new(@model_class)

  # primary key to look up an item to update
  builder.hash_key = dump_attribute(@model_class.hash_key, @hash_key)
  builder.range_key = dump_attribute(@model_class.range_key, @range_key) if @model_class.range_key?

  # changed attributes to persist
  changes = @attributes.dup
  changes = add_timestamps(changes, skip_created_at: true)
  changes_dumped = Dynamoid::Dumping.dump_attributes(changes, @model_class.attributes)

  builder.set_attributes(changes_dumped)

  # given a block
  if @item_updater
    builder.set_attributes(@item_updater.attributes_to_set)
    builder.remove_attributes(@item_updater.attributes_to_remove)

    @item_updater.attributes_to_add.each do |name, value|
      # The ADD section in UpdateExpressions requires values to be a
      # set to update a set attribute.
      # Allow specifying values as any Enumerable collection (e.g. Array).
      # Allow a single value not wrapped into a Set
      if @model_class.attributes[name][:type] == :set
        value = value.is_a?(Enumerable) ? Set.new(value) : Set[value]
      end

      builder.add_value(name, value)
    end

    @item_updater.attributes_to_delete.each do |name, value|
      # The DELETE section in UpdateExpressions requires values to be a
      # set to update a set attribute.
      # Allow specifying values as any Enumerable collection (e.g. Array).
      # Allow a single value not wrapped into a Set
      value = value.is_a?(Enumerable) ? Set.new(value) : Set[value]

      builder.delete_value(name, value)
    end
  end

  # require primary key to exist
  condition_expression = "attribute_exists(#{@model_class.hash_key})"
  if @model_class.range_key?
    condition_expression += " AND attribute_exists(#{@model_class.range_key})"
  end
  builder.condition_expression = condition_expression

  builder.request
end

#observable_by_user_result ⇒ Object 



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 41

def observable_by_user_result
  nil
end

#on_commit ⇒ Object 



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 29

def on_commit; end

#on_registration ⇒ Object 



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 19

def on_registration
  validate_primary_key!
  Dynamoid::Persistence::UpdateValidations.validate_attributes_exist(@model_class, @attributes)

  if @block
    @item_updater = ItemUpdater.new(@model_class)
    @block.call(@item_updater)
  end
end

#on_rollback ⇒ Object 



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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 31

def on_rollback; end

#skipped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dynamoid/transaction_write/update_fields.rb', line 37

def skipped?
  @attributes.empty? && (!@item_updater || @item_updater.empty?)
end