Class: File

Inherits:
Object
  • Object
show all
Defined in:
lib/utils/extend/file.rb

Overview

Reopen the core ruby File class and add the below methods to it.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.sister_filepath(caller, extension, method_symbol) ⇒ Object

Get the full filepath of a sister file that potentially lives in the same directory that the leaf class is executing from and has the same name as the leaf class but a different extension.

Usage

If class OpenFoo:Bar extends class OpenFoo:Baz and we are looking for an INI file in the folder that OpenFoo:Bar lives in we can call this method within OpenFoo:Baz like this.

ini_filepath = sister_filepath( "ini", :execute )
# => /var/lib/gems/2.5.0/gems/fooey-0.2.99/lib/barry/bazzy/bar.ini

Common Implementation

Object orientation scuppers the commonly used technique which derives the path from __FILE__

class_directory = File.dirname( __FILE__ )
leaf_class_name = self.class.name.split(":").last.downcase
sister_filepath = File.join ( class_directory, "#{leaf_class_name}.#{extension}" )

With object orientation - running the above code within the abstracted (parent) class would produce a resultant filepath based on the folder the parent class is in rather than the extended “concrete” class.

Value Proposition

You can call this method from the parent (abstract) class and it will still correctly return the path to the potential sister file living in the directory that the leaf class sits in.

Put differently - this extension method allows code executing in the parent class to correctly pinpoint a file in the directory of the leaf class be it in the same or a different folder.

Parameters:

  • caller —

    the calling class object usually passed in using self

  • extension —

    the extension of a sister file that carries the same simple (downcased) name of the leaf class of this method’s caller.

    Omit the (segregating) period character when providing this extension parameter.

  • method_symbol —

    the method name in symbolic form of any method defined in the leaf class even if the method overrides one of the same name in the parent class.

Returns:

  • the filepath of a potential sister file living in the same directory as the class, bearing the same (downcased) name as the class with the specified extension.



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# File 'lib/utils/extend/file.rb', line 61

def self.sister_filepath caller, extension, method_symbol

  leaf_classname = caller.class.name.split(":").last.downcase
  execute_method = caller.method( method_symbol )
  leaf_classpath = execute_method.source_location.first
  leaf_directory = File.dirname( leaf_classpath )
  lower_filename = "#{leaf_classname}.#{extension}"
  return File.join( leaf_directory, lower_filename )

end

Instance Method Details

#log_contents(file_context) ⇒ Object

This method adds (logging its own contents) behaviour to the standard library File class. If this File points to a directory - that folder’s single level content files are listed inside the logs.

The DEBUG log level is used for logging. To change this create a new parameterized method.

Parameters:

  • file_context (String) —

    context denotes the whys and wherefores of this file.



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# File 'lib/utils/extend/file.rb', line 82

def log_contents file_context

  ## This will fail - add physical raise statement.
  Throw.if_not_exists self

  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }
  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }
  log.debug(x) { "# -- The File Path to Log => #{self}" }

  hr_file_size = PrettyPrint.byte_size( File.size(self) )
  dotless_extension = File.extname( self )[1..-1]
  parent_dir_name = File.basename( File.dirname( self ) )
  file_name = File.basename self
  is_zip = dotless_extension.eql? "zip"

  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }
  log.debug(x) { "# -- File Name => #{file_name}" }
  log.debug(x) { "# -- File Size => #{hr_file_size}" }
  log.debug(x) { "# -- File Type => #{file_context}" }
  log.debug(x) { "# -- In Folder => #{parent_dir_name}" }
  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }

  log.debug(x) { "File #{file_name} is a zip (binary) file." } if is_zip
  return if is_zip

  File.open( self, "r") do | file_obj |
    line_no = 1
    file_obj.each_line do | file_line |
      line_num = sprintf '%03d', line_no
      clean_line = file_line.chomp.strip
      log.debug(x) { "# -- [#{line_num}] - #{clean_line}" }
      line_no += 1
    end
  end

  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }
  log.debug(x) { "# -- [#{file_context}] End of File [ #{File.basename(self)} ]" }
  log.debug(x) { "# -- ------------------------------------------------------------------------ #" }

end