RPG Maker VX Ace - Save File Doctor

%Q(
╔════╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═════╗
║ ╔══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╩═══╗ ║
╠─╣                             Save File Doctor.                            ╠─╣
╠─╣                           by RPG Maker Source.                           ╠─╣
╠─╣                          www.rpgmakersource.com                          ╠─╣
║ ╚══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╦═══╝ ║
╠════╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═╤═╩═════╣
║ ┌────┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴─────┐ ║
╠─┤ Version 1.1.0                   28/05/15                        DD/MM/YY ├─╣
║ └────┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬─────┘ ║
╠══════╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══╧═══════╣
║                                                                              ║
║               This work is protected by the following license:               ║
║     ╔══════════════════════════════════════════════════════════════════╗     ║
║     │                                                                  │     ║
║     │ Copyright © 2014 Maker Systems.                                  │     ║
║     │                                                                  │     ║
║     │ This software is provided 'as-is', without any kind of           │     ║
║     │ warranty. Under no circumstances will the author be held         │     ║
║     │ liable for any damages arising from the use of this software.    │     ║
║     │                                                                  │     ║
║     │ Permission is granted to anyone to use this software on their    │     ║
║     │ free or commercial games made with a legal copy of RPG Maker     │     ║
║     │ VX Ace, as long as Maker Systems - RPG Maker Source is           │     ║
║     │ credited within the game.                                        │     ║
║     │                                                                  │     ║
║     │ Selling this code or any portions of it 'as-is' or as part of    │     ║
║     │ another code, is not allowed.                                    │     ║
║     │                                                                  │     ║
║     │ The original header, which includes this copyright notice,       │     ║
║     │ must not be edited or removed from any verbatim copy of the      │     ║
║     │ sotware nor from any edited version.                             │     ║
║     │                                                                  │     ║
║     ╚══════════════════════════════════════════════════════════════════╝     ║
║                                                                              ║
║                                                                              ║
╠══════════════════════════════════════════════════════════════════════════════╣
║ 1. VERSION HISTORY.                                                        ▼ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║ • Version 1.0.0, 27/12/14 - (DD/MM/YY).                                      ║
║                                                                              ║
║ • Version 1.1.0, 28/05/15 - (DD/MM/YY).                                      ║
║                                                                              ║
╠══════════════════════════════════════════════════════════════════════════════╣
╠══════════════════════════════════════════════════════════════════════════════╣
║ 2. USER MANUAL.                                                            ▼ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║ ┌──────────────────────────────────────────────────────────────────────────┐ ║
║ │ ■ Introduction.                                                          │ ║
║ └┬┬┬┬──────────────────────────────────────────────────────────────────┬┬┬┬┘ ║
║                                                                              ║
║  Hello there! This script is "plug and play", you can simply insert it       ║
║  into your project and it will perform flawlessly.                           ║
║                                                                              ║
║  Save File Doctor aims to fix the most common problem encountered when       ║
║  loading a save file after adding a new script to your project.              ║
║                                                                              ║
║  The problem is usually caused by the lack of initialization for variables   ║
║  used in the recently created script. When loading an old save file, some    ║
║  things were already initialized and the new script will assume that's also  ║
║  the case for its own variables.                                             ║
║                                                                              ║
║  It is also useful for DLC or patching systems, since it would take care     ║
║  of said problem in case you add scripts that way.                           ║
║                                                                              ║
║  We hope you enjoy it.                                                       ║
║                                                                              ║
║  Thanks for choosing our products.                                           ║
║                                                                              ║
╠══════════════════════════════════════════════════════════════════════════════╣
╠══════════════════════════════════════════════════════════════════════════════╣
║ 3. NOTES.                                                                  ▼ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║  Have fun and enjoy!                                                         ║
║                                                                              ║
╠══════════════════════════════════════════════════════════════════════════════╣
╠══════════════════════════════════════════════════════════════════════════════╣
║ 4. CONTACT.                                                                ▼ ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║  Need support? Post in our forums!                                           ║
║                                                                              ║
║  forums.rpgmakersource.com                                                   ║
║                                                                              ║
║  Keep in touch with us and be the first to know about new releases:          ║
║                                                                              ║
║  www.rpgmakersource.com                                                      ║
║  www.facebook.com/RPGMakerSource                                             ║
║  www.twitter.com/RPGMakerSource                                              ║
║  www.youtube.com/user/RPGMakerSource                                         ║
║                                                                              ║
║  Get involved! Have an idea for a system? Let us know.                       ║
║                                                                              ║
║  Spread the word and help us reach more people so we can continue creating   ║
║  awesome resources for you!                                                  ║
║                                                                              ║
╚══════════════════════════════════════════════════════════════════════════════╝)

#==============================================================================
# ** MakerSystems
#------------------------------------------------------------------------------
#  Module for our systems.
#==============================================================================

module MakerSystems

  #============================================================================
  # ** SaveFileDoctor
  #----------------------------------------------------------------------------
  #  Ph.D in game development and family care.
  #============================================================================

  module SaveFileDoctor

    #----------------------------------------------------------------------
    # * Custom Case for Game_Actors.                                  [NEW]
    #----------------------------------------------------------------------
    def self.custom_case_for_game_actors(patient, current)
      # Get data array that contains each Actor.
      patient_data = patient.instance_variable_get('@data')
      # Go through each Actor.
      patient_data.each do |actor|
        # Next if actor is nil. Needed because how Game_Actors handles [].
        next unless actor
        # Get current actor from current Game_Actors using patient's id.
        current_actor = current[actor.instance_variable_get('@actor_id')]
        # Fixes each of patient's Game_Actor objects.
        fix_object(actor, current_actor)
        # Healing process for each instance variable of this actor.
        child_health(object_data(actor), object_data(current_actor))
      end
    end
    #----------------------------------------------------------------------
    # * Heal.                                                         [NEW]
    #----------------------------------------------------------------------
    def self.heal(contents)
      # Will keep track of repaired objects to avoid a stack overflow.
      @ms_save_file_doctor_ids = []
      # Goes through each object in contents hash.
      contents.each_value do |patient|
        # Updated version of this Object.
        current = patient.class.new
        # Fixes this (loaded) Object  with the help of its updated version.
        fix_object(patient, current)
        # Starts the healing process for each instance variable.
        child_health(object_data(patient), object_data(current))
      end
      # No need to keep the objects ids in memory.
      @ms_save_file_doctor_ids = nil
    end
    #----------------------------------------------------------------------
    # * Enumerable Child Processing.                                  [NEW]
    #----------------------------------------------------------------------
    def self.enum_child(patient, current)
      # Iterates loaded version and updated version as a sequence.
      patient.zip(current).each do |p_value, c_value|
        # If Enumerable, there might be instanceable Objects inside it.
        enum_child(p_value.to_a, c_value.to_a) if Enumerable === p_value
        # Ignore if it can't be instanced.
        next unless p_value.class.respond_to?(:new)
        # Stop if this Object was already healed to avoid a stack overflow.
        return if @ms_save_file_doctor_ids.include?(p_value.__id__)
        # Saves current Object id.
        @ms_save_file_doctor_ids << p_value.__id__
        # Fixes this Object with the help of its updated version.
        fix_object(p_value, c_value)
        # Healing process for each instance variable of this Object.
        child_health(object_data(p_value), object_data(c_value))
      end
    end
    #----------------------------------------------------------------------
    # * Object Data.                                                  [NEW]
    #----------------------------------------------------------------------
    def self.object_data(object)
      # Returns a hash with each instance variable name and value.
      Hash[
        object.instance_variables.map do |name|
          [name, object.instance_variable_get(name)]
        end
      ]
    end
    #----------------------------------------------------------------------
    # * Fix Object.                                                   [NEW]
    #----------------------------------------------------------------------
    def self.fix_object(patient, current)
      # Name of the method that should especially handle this object.
      special = "custom_case_for_#{patient.class.name.downcase}"
      # Attempts special handling.
      send(special, patient, current) if respond_to?(special)
      # Adds new data to loaded Object's data target.
      data = object_data(current).merge!(object_data(patient))
      # Uses the correct data target to set each instance variable.
      data.each { |name, value| patient.instance_variable_set(name, value) }
    end
    #----------------------------------------------------------------------
    # * Child Health.                                                 [NEW]
    #----------------------------------------------------------------------
    def self.child_health(patient, current)
      # Goes through each instance variable.
      patient.each do |name, value|
        # If Enumerable, there might be instanceable Objects inside it.
        enum_child(value.to_a, current[name].to_a) if Enumerable === value
        # Ignore if it can't be instanced.
        next unless value.class.respond_to?(:new)
        # Stop if this Object was already healed to avoid a stack overflow.
        return if @ms_save_file_doctor_ids.include?(value.__id__)
        # Saves current Object id.
        @ms_save_file_doctor_ids << value.__id__
        # Fixes this Object with the help of its updated version.
        fix_object(value, current[name])
        # Healing process for each instance variable of this Object.
        child_health(object_data(value), object_data(current[name]))
      end
    end

  end

end

#==============================================================================
# ** DataManager
#------------------------------------------------------------------------------
#  This module manages the database and game objects. Almost all of the
# global variables used by the game are initialized by this module.
#==============================================================================

module DataManager

  class << self

    #------------------------------------------------------------------------
    # * Alias Extract Save Contents.                                    [NEW]
    #------------------------------------------------------------------------
    alias_method(:ms_save_file_doctor_original_extract_save_contents,
                 :extract_save_contents)
    #------------------------------------------------------------------------
    # * Extract Save Contents.                                          [MOD]
    #------------------------------------------------------------------------
    def extract_save_contents(contents)
      # Healthcare. Object repairing is handled at a local level.
      MakerSystems::SaveFileDoctor.heal(contents)
      # Proceeds with the original method, using repaired contents.
      ms_save_file_doctor_original_extract_save_contents(contents)
    end

  end

end