# Aws::Record

[![Build Status](https://travis-ci.org/aws/aws-sdk-ruby-record.svg?branch=main)](https://travis-ci.org/aws/aws-sdk-ruby-record) [![Code Climate](https://codeclimate.com/github/aws/aws-sdk-ruby-record.svg)](https://codeclimate.com/github/aws/aws-sdk-ruby-record) [![Coverage Status](https://coveralls.io/repos/github/aws/aws-sdk-ruby-record/badge.svg?branch=main)](https://coveralls.io/github/aws/aws-sdk-ruby-record?branch=main)

A data mapping abstraction over the AWS SDK for Ruby's client for Amazon
DynamoDB.

This library is currently under development. More features will be added as we
approach general availability, and while our initial release has as small of an
API surface area as possible, the interface may change before the GA release.

We would like to invite you to be a part of the ongoing development of this gem.
We welcome your contributions, and would also be happy to hear from you about
how you would like to use this gem. Feature requests are welcome.

## Table of Contents

* [Installation](https://github.com/aws/aws-sdk-ruby-record#installation)
* [Usage](https://github.com/aws/aws-sdk-ruby-record#usage)
  * [Item Operations](https://github.com/aws/aws-sdk-ruby-record#item-operations) 
  * [BatchGetItem / BatchWriteItem](https://github.com/aws/aws-sdk-ruby-record#batchgetitem-and-batchwriteitem)
  * [Transactions](https://github.com/aws/aws-sdk-ruby-record#transactions)
  * [Inheritance Support](https://github.com/aws/aws-sdk-ruby-record#inheritance-support)

## Links of Interest

* [Documentation](http://docs.aws.amazon.com/awssdkrubyrecord/api/)
* [Change Log](https://github.com/aws/aws-sdk-ruby-record/blob/main/CHANGELOG.md)
* [Issues](https://github.com/aws/aws-sdk-ruby-record/issues)
* [License](http://aws.amazon.com/apache2.0/)

---
## Installation

`Aws::Record` is available as the `aws-record` gem from RubyGems.

```shell
gem install 'aws-record'
```

```ruby
gem 'aws-record', '~> 2.0'
```

This automatically includes a dependency on the `aws-sdk-dynamodb` gem (part of the modular version-3 of 
the [AWS SDK for Ruby](https://aws.amazon.com/sdk-for-ruby/). If you need to pin to a specific version, 
you can add [aws-sdk-dynamodb](https://rubygems.org/gems/aws-sdk-dynamodb) 
or [aws-sdk-core](https://rubygems.org/gems/aws-sdk-core) gem in your
Gemfile.

---
## Usage

To create a model that uses `aws-record` features, simply include the provided
module:

```ruby
class MyModel
  include Aws::Record
end
```

You can then specify attributes using the `aws-record` DSL:

```ruby
class MyModel
  include Aws::Record
  integer_attr :id, hash_key: true
  string_attr  :name, range_key: true
  boolean_attr :active, database_attribute_name: 'is_active_flag'
end
```

If a matching table does not exist in DynamoDB, you can use the TableConfig DSL to create your table:

```ruby
cfg = Aws::Record::TableConfig.define do |t|
  t.model_class(MyModel)
  t.read_capacity_units(5)
  t.write_capacity_units(2)
end
cfg.migrate!
```

With a table in place, you can then use your model class to manipulate items in
your table:

```ruby
item = MyModel.find(id: 1, name: 'Hello Record')
item.active = true
item.save
item.delete!

MyModel.find(id: 1, name: 'Hello Record') # => nil

item = MyModel.new
item.id = 2
item.name = 'Item'
item.active = false
item.save
```
---
### Item Operations
You can use item operations on your model class to read and manipulate item(s).

More info under following documentation:
* [Item Operations](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/ItemOperations.html)
* [Item Operations Class Methods](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/ItemOperations/ItemOperationsClassMethods.html)

**Example usage**
```ruby
class MyModel
  include Aws::Record
  integer_attr :uuid,   hash_key: true
  string_attr  :name, range_key: true
  integer_attr :age
end

item = MyModel.find(id: 1, name: 'Foo')
item.update(id: 1, name: 'Foo', age: 1)
```

---

### `BatchGetItem` and `BatchWriteItem`
Aws Record provides [BatchGetItem](https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#batch_get_item-instance_method)
and [BatchWriteItem](https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#batch_write_item-instance_method)
support for aws-record models.

More info under the following documentation:

* [Batch](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/Batch.html)
* [BatchWrite](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/BatchWrite.html)
* [BatchRead](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/BatchRead.html)

See examples below to see the feature in action.

**`BatchGetItem` Example**
```ruby
class Lunch
  include Aws::Record
  integer_attr :id,   hash_key: true
  string_attr  :name, range_key: true
end

class Dessert
  include Aws::Record
  integer_attr :id,   hash_key: true
  string_attr  :name, range_key: true
end

# batch operations
operation = Aws::Record::Batch.read do |db|
  db.find(Lunch, id: 1, name: 'Papaya Salad')
  db.find(Lunch, id: 2, name: 'BLT Sandwich')
  db.find(Dessert, id: 1, name: 'Apple Pie')
end

# BatchRead is enumerable and handles pagination
operation.each { |item| item.id }

# Alternatively, BatchRead provides a lower level interface 
# through: execute!, complete? and items.
# Unprocessed items can be processed by calling:
operation.execute! until operation.complete?
```

**`BatchWriteItem` Example**
```ruby
class Breakfast
  include Aws::Record
  integer_attr :id,   hash_key: true
  string_attr  :name, range_key: true
  string_attr  :body
end

# setup
eggs = Breakfast.new(id: 1, name: 'eggs').save!
waffles = Breakfast.new(id: 2, name: 'waffles')
pancakes = Breakfast.new(id: 3, name: 'pancakes')

# batch operations
operation = Aws::Record::Batch.write(client: Breakfast.dynamodb_client) do |db|
  db.put(waffles)
  db.delete(eggs)
  db.put(pancakes)
end

# unprocessed items can be retried by calling Aws::Record::BatchWrite#execute!
operation.execute! until operation.complete?
```
---
### Transactions
Aws Record provides [TransactGetItems](https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#transact_get_items-instance_method)
and [TransactWriteItems](https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#transact_write_items-instance_method)
support for aws-record models.

More info under the [Transactions](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/Transactions.html) 
documentation.

See examples below to see the feature in action.

**`TransactGetItems` Example**
```ruby
class TableOne
  include Aws::Record
  string_attr :uuid, hash_key: true
end

class TableTwo
  include Aws::Record
  string_attr :hk, hash_key: true
  string_attr :rk, range_key: true
end

results = Aws::Record::Transactions.transact_find(
  transact_items: [
    TableOne.tfind_opts(key: { uuid: 'uuid1234' }),
    TableTwo.tfind_opts(key: { hk: 'hk1', rk: 'rk1'}),
    TableTwo.tfind_opts(key: { hk: 'hk2', rk: 'rk2'})
  ]
) # => results.responses contains nil or marshalled items
results.responses.map { |r| r.class } # [TableOne, TableTwo, TableTwo]
```

**`TransactWriteItems` Example**
```ruby
# same models as `TransactGetItems` Example
check_exp = TableOne.transact_check_expression(
  key: { uuid: 'foo' },
  condition_expression: 'size(#T) <= :v',
  expression_attribute_names: {
    '#T' => 'body'
  },
  expression_attribute_values: {
    ':v' => 1024
  }
)
new_item = TableTwo.new(hk: 'hk1', rk: 'rk1', body: 'Hello!')
update_item_1 = TableOne.find(uuid: 'bar')
update_item_1.body = 'Updated the body!'
put_item = TableOne.new(uuid: 'foobar', body: 'Content!')
update_item_2 = TableTwo.find(hk: 'hk2', rk: 'rk2')
update_item_2.body = 'Update!'
delete_item = TableOne.find(uuid: 'to_be_deleted')

Aws::Record::Transactions.transact_write(
  transact_items: [
    { check: check_exp },
    { save: new_item },
    { save: update_item_1 },
    {
      put: put_item,
      condition_expression: 'attribute_not_exists(#H)',
      expression_attribute_names: { '#H' => 'uuid' },
      return_values_on_condition_check_failure: 'ALL_OLD'
    },
      { update: update_item_2 },
      { delete: delete_item }
  ]
)
```
---
### Inheritance Support
Aws Record models can be extended using standard ruby inheritance. The child model must 
include `Aws::Record` in their model and the following will be inherited:

* [set_table_name](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/RecordClassMethods.html#set_table_name-instance_method)
* [Attributes and Keys](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/Attributes.html#initialize-instance_method)
* Mutation Tracking:
  * [enable_mutation_tracking](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/RecordClassMethods.html#enable_mutation_tracking-instance_method)
  * [disable_mutation_tracking](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/RecordClassMethods.html#disable_mutation_tracking-instance_method)
* [local_secondary_indexes](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/SecondaryIndexes/SecondaryIndexesClassMethods.html#local_secondary_indexes-instance_method)
* [global_secondary_indexes](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/SecondaryIndexes/SecondaryIndexesClassMethods.html#global_secondary_indexes-instance_method)
* [configure_client](https://docs.aws.amazon.com/sdk-for-ruby/aws-record/api/Aws/Record/ClientConfiguration.html#configure_client-instance_method)

See example below to see the feature in action.

```ruby
class Animal
  include Aws::Record
  string_attr :name, hash_key: true
  integer_attr :age
end

class Dog < Animal
  include Aws::Record
  boolean_attr :family_friendly
end

dog = Dog.find(name: 'Sunflower')
dog.age = 3
dog.family_friendly = true
```