Class: AWS::DynamoDB::AttributeCollection::UpdateBuilder

Inherits:
Object
  • Object
show all
Includes:
Types
Defined in:
lib/aws/dynamo_db/attribute_collection.rb

Overview

Used to build a batch of updates to an item's attributes. See #update for more information.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Types

#format_attribute_value, #value_from_response, #values_from_response_hash

Constructor Details

#initializeUpdateBuilder

Returns a new instance of UpdateBuilder.


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# File 'lib/aws/dynamo_db/attribute_collection.rb', line 238

def initialize
  @updates = {}
end

Instance Attribute Details

#updatesObject (readonly)


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# File 'lib/aws/dynamo_db/attribute_collection.rb', line 233

def updates
  @updates
end

Instance Method Details

#add(attributes) ⇒ Object

Adds to the values of one or more attributes. See AWS::DynamoDB::AttributeCollection#add for more information.


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# File 'lib/aws/dynamo_db/attribute_collection.rb', line 262

def add attributes
  attribute_updates("ADD", attributes)
end

#delete(*args) ⇒ Object

Deletes one or more attributes or attribute values. See AWS::DynamoDB::AttributeCollection#delete for more information.


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# File 'lib/aws/dynamo_db/attribute_collection.rb', line 269

def delete *args
  if args.first.kind_of?(Hash)
    attribute_updates("DELETE",
                      args.shift,
                      :setify => true)
  else
    add_updates(args.inject({}) do |u, name|
                  u.update(name.to_s => {
                             :action => "DELETE"
                           })
                end)
  end
end

#set(attributes) ⇒ Object Also known as: put, merge!

Replaces the values of one or more attributes. See AWS::DynamoDB::AttributeCollection#set for more information.


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# File 'lib/aws/dynamo_db/attribute_collection.rb', line 244

def set attributes
  to_delete = []
  attributes = attributes.inject({}) do |attributes, (name, value)|
    if value == nil
      to_delete << name
    else
      attributes[name] = value
    end
    attributes
  end
  attribute_updates("PUT", attributes)
  delete(*to_delete)
end