https://github.com/nxt-insurance/nxt_init
Define initializers and attribute readers for your arguments with a single line of code
https://github.com/nxt-insurance/nxt_init
attribute-readers initializer ruby ruby-on-rails sugar
Last synced: 2 months ago
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Define initializers and attribute readers for your arguments with a single line of code
- Host: GitHub
- URL: https://github.com/nxt-insurance/nxt_init
- Owner: nxt-insurance
- License: mit
- Created: 2019-02-01T18:35:03.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2024-04-25T07:23:04.000Z (about 1 year ago)
- Last Synced: 2024-04-25T08:29:29.098Z (about 1 year ago)
- Topics: attribute-readers, initializer, ruby, ruby-on-rails, sugar
- Language: Ruby
- Homepage:
- Size: 88.9 KB
- Stars: 21
- Watchers: 14
- Forks: 0
- Open Issues: 15
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
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README
[](https://circleci.com/gh/nxt-insurance/nxt_init)
# NxtInit
Create an initializer that accepts option arguments and define private readers for your
arguments at the same time.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'nxt_init'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install nxt_init
## Usage
NxtInit removes some boilerplate. Instead of writing your initializer and (private) attribute readers each and every time like so:
```ruby
class GetSafe
def initialize(frontend:, backend:)
@frontend = frontend
@backend = backend
end
private
attr_reader :frontend, :backend
end
```
You can instead do the following:
```ruby
class GetSafe
include NxtInit
attr_init :frontend, :backend
end
GetSafe.new # KeyError (NxtInit attr_init key :frontend was missing at initialization!
GetSafe.new(frontend: 'React', backend: 'Ruby on Rails') #
```
### Optional arguments and defaults
In order to provide default values you can simply use the hash syntax to define your defaults.
If you want to make an attribute optional, just pass nil as the default argument.
If there is no default value and you did not provide one when initializing your class, you will get a KeyError.
```ruby
class GetSafe
include NxtInit
attr_init frontend: 'React',
backend: -> { 'Ruby on Rails' },
middleware: nil
end
GetSafe.new #
```
### BEWARE of Global Defaults
```ruby
class GetSafe
include NxtInit
attr_init frontend: [], # this is global and shared between all classes
backend: -> { [] } # this is local to an instance of the class
end
GetSafe.new.send(:frontend).object_id => 70236117045360
GetSafe.new.send(:frontend).object_id => 70236117045360
GetSafe.new.send(:backend).object_id => 70236143937240
GetSafe.new.send(:backend).object_id => 70236121600680
```
### Preprocessors
If you want to preprocess your attribute somehow, you can define a preprocessor block to which the original attribute will be yielded.
Note that you can also call methods in your block if you have some heavier lifting to do.
```ruby
class GetSafe
include NxtInit
attr_init date: -> (date) { date && (date.is_a?(Date) ? date : Date.parse(date)) }
end
GetSafe.new(date: '2020/12/12').send(:date) # will give you the date
GetSafe.new(date: nil).send(:date) # would give you nil
GetSafe.new # would raise KeyError (NxtInit attr_init key :date was missing at initialization!)
```
Also you can still pass in nil if your block can handle it. If the attribute is not provided on initialization again a KeyError will be raised.
### Inheritance
When you inherit from a class that already includes NxtInit you can add further attributes to your subclass and overwrite existing options
simply by using attr_init for the same attributes. Check out the specs for more examples.
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
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`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/nxt-insurance/nxt_init.
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).