ChainFlow

Helps to refactor data processing with functions composition.

Installation

Add this line to your application's Gemfile:

gem chain_flow

Or install it yourself as:

$ gem install chain_flow

Usage

Interface

Including ChainFlow adds two methods: flow and chain. flow accepts initial data as an argument and all the processing functions go in a block.

chain receives initial data in a block and returns and object that can be further chained with processing functions. Call fetch to obtain the final result.

Processing functions should accept at least one parameter - the data. When calling these functions inside flow or chaining them with chain this first parameter should be ommitted.

Example

require 'chain_flow'

class Worker
  include ChainFlow

  def flow_process
    flow(Array.new) do
      add_answer
      multiple_by(3)
    end
  end

  def chain_process
    chain { Array.new }.add_answer.multiple_by(3).fetch
  end

  private

  # first processing function
  def add_answer(data)
    data << 42
  end

  # second processing function
  def multiple_by(data, count)
    data * count
  end
end

Worker.new.flow_process  #=> [42, 42, 42]
Worker.new.chain_process #=> [42, 42, 42]

How does it work?

Notice that both flow and chain capture the caller context with closure. Calls to processing fuctions with ommitted first data parameter are intercepted with method_missing and called in captured caller context instead with initial data pipelined through them one-by-one.