Markdown Template Engine

markdown-template-engine.rb

PWD = File.expand_path(File.dirname(__FILE__))
VARIABLE_REGEX = %r{\<[A-Z\-]*\>}

class MTEngineError
  class << self
    def not_a_file(filepath)
      raise "#{filepath} is not a file or does not exist"
    end
  end
end

class MTEngine
  attr_accessor :filepath, :filename, :filecontent, :variables, :values

  def initialize(filename)
    self.variables = []
    self.values = {}

    if filename.include? "/"
      self.filepath = filename
    else
      self.filepath = File.join(PWD, filename)
    end

    extn = File.extname filepath
    self.filename = File.basename filepath, extn

    MTEngineError.not_a_file(filepath) unless File.file?(filepath)

    read!
    fetch_variables!
  end

  def read!
    self.filecontent = File.readlines(self.filepath).join
  end

  def fetch_variables!
    self.variables = filecontent.scan(VARIABLE_REGEX).uniq
  end

  def store_values!
    variables.each do |variable|
      puts "#{variable}: "
      self.values[variable] = gets.chomp
    end

    values
  end

  def replace
    dup_content = filecontent.dup
    variables.each do |variable|
      dup_content.gsub! variable, values[variable]
    end

    dup_content
  end

  def replace_and_save!
    newfilepath = filepath.sub(filename, "#{filename}_#{Time.now.to_i}")
    newfile = File.new(newfilepath, "w")
    newfile.puts replace
    newfile.close

    puts "Saved output to #{newfilepath}!"
  end
end

sample_irb_session

# Load file into irb session
irb -r ./markdown-template-engine.rb

# Load the markdown template
> mt = MTEngine.new("/Users/user/markdown.md")

# Store values of all variables in markdown
> mt.store_values!

# Replace all variables with your values
> mt.replace

# Save new file
> mt.replace_and_save!

variable-naming-convention.md

Variables are strings in the markdown file that are meant to replaced with values with the markdown-template-engine.

They can only be capital letters enclosed in lesser/greater than symbols. They can not contain numbers or lowercase letters. They can however contain hypens (-).

An example for a variable could be, <NAME> or <FULL-NAME>

Variables CAN NOT be, <name> or <full0name>.