Class: FakePipe::Piper

Inherits:
Object
  • Object
show all
Defined in:
lib/fake_pipe/piper.rb

Overview

This class cooridinates between all the text blocks. The class is initialized with some input io, an output io, and an adapter.

## Adapter An adapter is created by creating a module directly under fake_pipe. The module must respond to ‘text_blocks` which will return all the `TextBlock` classes needed to call `on_config` and `on_cell`.

## General IO Flow The ‘run` method is probably the most interesting. It streams in `each_line` of the input `io` and will output either the same line or the parsed line from the `TextObject#parse`. It’s the responsibility of the TextBlock to extract relevant table, column, cell information. This class will make keep track of when to mutate cell.

Most lines from ‘io` should be passed directly to the `outputter`

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io:, outputter:, adapter:) ⇒ Piper

Returns a new instance of Piper.

Parameters:

  • adapter (String) —

    should be a module file directly under the ‘fake_pipe’ path



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# File 'lib/fake_pipe/piper.rb', line 22

def initialize(io:, outputter:, adapter:)
  self.configs = {}
  self.io = io
  self.outputter = outputter
  register_adapter(adapter)
end

Instance Attribute Details

#configs ⇒ Object

Returns the value of attribute configs.



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# File 'lib/fake_pipe/piper.rb', line 19

def configs
  @configs
end

#io ⇒ Object

Returns the value of attribute io.



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# File 'lib/fake_pipe/piper.rb', line 19

def io
  @io
end

#outputter ⇒ Object

Returns the value of attribute outputter.



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# File 'lib/fake_pipe/piper.rb', line 19

def outputter
  @outputter
end

#text_blocks ⇒ Object

Returns the value of attribute text_blocks.



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# File 'lib/fake_pipe/piper.rb', line 19

def text_blocks
  @text_blocks
end

Instance Method Details

#detect_and_start_text_block(line) ⇒ Object

Check if a line is the begining of a new text block. When it is, trigger the callbacks so the text block can initialize itself.



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# File 'lib/fake_pipe/piper.rb', line 59

def detect_and_start_text_block(line)
  text_blocks.detect do |block|
    matcher = block.match_start_text(line)
    if matcher && block.start_text? 
      block.on_start_text(matcher, line)
      true # result for detect
    end
  end
end

#on_cell(table:, column:, cell:) ⇒ String

Returns The mutated cell or the original if there’s no config for the table/column.

Returns:

  • (String) —

    The mutated cell or the original if there’s no config for the table/column.



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# File 'lib/fake_pipe/piper.rb', line 78

def on_cell(table:, column:, cell:)
  if config = configs[table].try(:[], column)
    Mutator.mutate(config, cell)
  else
    cell
  end
end

#on_config(table:, column:, config:) ⇒ Object

Delegate method to be called by the #text_objects to get config information from a table’s column



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# File 'lib/fake_pipe/piper.rb', line 71

def on_config(table:, column:, config:)
  table = (configs[table] ||= {})
  table[column] = config
end

#register_adapter(adapter) ⇒ Object 



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# File 'lib/fake_pipe/piper.rb', line 29

def register_adapter(adapter)
  adapter_module = "fake_pipe/#{adapter}"
  require adapter_module
  adapter_class = adapter_module.camelize.constantize
  self.text_blocks = adapter_class.text_blocks.map do |block_class|
    block_class.new(delegate: self)
  end

  # AnyBlock is a catch all and needs to come last.
  text_blocks << AnyBlock.new(delegate: self)
end

#run ⇒ Object 



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# File 'lib/fake_pipe/piper.rb', line 41

def run
  # used to track which text_block is currently in use
  current_block = text_blocks.last
  io.each_line do |line|
    if current_block.end_text?(line)
      output line
      current_block = detect_and_start_text_block(line)
    elsif configs[current_block.table]    # optimization: only parse of the text block has a table configuration
      output current_block.parse(line)
    else                                  # otherwise output the original line
      output line
    end
  end
end