README.md in ar-uuid-0.2.1 vs README.md in ar-uuid-0.2.2
- old
+ new
@@ -1,39 +1,32 @@
-# ActiveRecord::UUID
+# ar-uuid
-[](https://travis-ci.org/fnando/ar-uuid)
+[](https://github.com/fnando/ar-uuid)
[](https://codeclimate.com/github/fnando/ar-uuid)
-[](https://codeclimate.com/github/fnando/ar-uuid/coverage)
[](https://rubygems.org/gems/ar-uuid)
[](https://rubygems.org/gems/ar-uuid)
-Override migration methods to support UUID columns without having to be explicit about it.
+Override migration methods to support UUID columns without having to be explicit
+about it.
-What this gem will do for you:
-
-- When creating new tables, will set the `id` column as `uuid`.
-- When creating associations with `t.belongs_to`, `t.references` or `add_reference`, will set the column type as `uuid`.
-
## Installation
-Add this line to your application's Gemfile:
+```bash
+gem install ar-uuid
+```
+Or add the following line to your project's Gemfile:
+
```ruby
gem "ar-uuid"
```
-And then execute:
-
- $ bundle
-
-Or install it yourself as:
-
- $ gem install ar-uuid
-
## Usage
-There's no setup. Just adding the gem to your Gemfile is enough. When you create a new table, the `id` column will be defined as `uuid`. This is also true for references.
+There's no setup. Just adding the gem to your Gemfile is enough. When you create
+a new table, the `id` column will be defined as `uuid`. This is also true for
+references.
```ruby
create_table :users
add_reference :posts, :users
@@ -42,25 +35,58 @@
# or
t.references :user
end
```
-If you need a serial column, AR's PostgreSQL supports the `bigserial` column type.
+If you need a serial column, AR's PostgreSQL supports the `bigserial` column
+type.
```ruby
create_table :users do |t|
t.column :position, :bigserial, null: false
end
```
-### Disadvantages
+### Sorting
-There is one big disadvantage on using uuid identifiers: you can't use methods like `ActiveRecord::FinderMethods::InstanceMethods#first` and `ActiveRecord::FinderMethods::InstanceMethods#last`, since they are scoped to the sequential id.
+#### Rails 6.0 or newer
-The easiest alternative is ordering results and calling `first`/`last`. You can either create a sequence, or use the `created_at`/`updated_at` columns:
+If you're using Rails 6.0 or newer, you can set a default sorting with
+[ActiveRecord::ModelSchema.implicit_order_column](https://api.rubyonrails.org/classes/ActiveRecord/ModelSchema.html#method-c-implicit_order_column),
+so methods like `ActiveRecord::FinderMethods::InstanceMethods#first` and
+`ActiveRecord::FinderMethods::InstanceMethods#last` will work transparently, as
+long as you define another column for sorting, such as `created_at` (you may
+need to add an index).
+The following example sets a default behavior to always sort using `created_at`
+(when available). On your abstract model, add the following lines:
+
```ruby
+class ApplicationRecord < ActiveRecord::Base
+ self.abstract_class = true
+
+ def self.inherited(child_class)
+ super
+
+ return unless child_class.columns.any? {|col| col.name == "created_at" }
+
+ child_class.implicit_order_column ||= "created_at"
+ end
+end
+```
+
+#### Older Rails versions
+
+For older Rails versions, you can't use methods like
+`ActiveRecord::FinderMethods::InstanceMethods#first` and
+`ActiveRecord::FinderMethods::InstanceMethods#last`, since they are scoped to
+the sequential id.
+
+The easiest alternative is ordering results and calling `first`/`last`. You can
+either create a sequence, or use the `created_at`/`updated_at` columns:
+
+```ruby
# Get first record
User.order(created_at: :asc).first
# Get last record
User.order(created_at: :desc).first
@@ -73,22 +99,35 @@
User.older.first
User.newer.first
```
-You can also replace `.first` with [ActiveRecord::FinderMethods::InstanceMethods#take](https://github.com/rails/rails/blob/f52354ad1d15120dcc5284714bee7ee3f052986c/activerecord/lib/active_record/relation/finder_methods.rb#L104), which will use the order implemented by the database.
+You can also replace `.first` with
+[ActiveRecord::FinderMethods::InstanceMethods#take](https://github.com/rails/rails/blob/f52354ad1d15120dcc5284714bee7ee3f052986c/activerecord/lib/active_record/relation/finder_methods.rb#L104),
+which will use the order implemented by the database.
There's no alternative to `.last`.
-## Development
+## Maintainer
-After checking out the repo, run `bin/setup` to install dependencies. Then, run `bin/console` for an interactive prompt that will allow you to experiment.
-4
-To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release` to create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
+- [Nando Vieira](https://github.com/fnando)
+## Contributors
+
+- https://github.com/fnando/ar-uuid/contributors
+
## Contributing
-1. Fork it ( https://github.com/fnando/ar-uuid/fork )
-2. Create your feature branch (`git checkout -b my-new-feature`)
-3. Commit your changes (`git commit -am 'Add some feature'`)
-4. Push to the branch (`git push origin my-new-feature`)
-5. Create a new Pull Request
+For more details about how to contribute, please read
+https://github.com/fnando/ar-uuid/blob/main/CONTRIBUTING.md.
+
+## License
+
+The gem is available as open source under the terms of the
+[MIT License](https://opensource.org/licenses/MIT). A copy of the license can be
+found at https://github.com/fnando/ar-uuid/blob/main/LICENSE.md.
+
+## Code of Conduct
+
+Everyone interacting in the ar-uuid project's codebases, issue trackers, chat
+rooms and mailing lists is expected to follow the
+[code of conduct](https://github.com/fnando/ar-uuid/blob/main/CODE_OF_CONDUCT.md).