before.cr

before hook for Crystal.

• crystal: 0.23.1

Installation

Add this to your application's shard.yml:

dependencies:
  before:
    github: maiha/before.cr
    version: 0.1.0

Usage

original code

Let's image some notification application.

class Notify
  def send(msg : String)
    # some logic to send message
  end
end

add before hook by before.cr

• 1. insert before signature befere def
• 2. insert __before__ at the beginning of method body

require "before"

class Notify
  before def send(msg : String)
    __before__
    # some logic to send message
  end
end

• 3. This generates following codes

class Notify
  def before_send(&callback : (String) ->)
    (@before_send  ||= [] of ((String) ->)) << callback
  end

  def send(msg : String)
    @before_send.try &.each &.call(msg)
    # some logic to send message
  end
end

• 4. now you can use before_send block where send is method name

notify = Notify.new
notify.before_send do |msg|
  raise "Do Not Disturb" unless (10..18) === Time.now.hour
end
notify.send("Come to my office now!")

CAUTIONS

• variable type must be defined
• doesn't work with blocks

Development

make test

Contributing

1. Fork it ( https://github.com/maiha/before.cr/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

Contributors

• maiha maiha - creator, maintainer