From: ahoward <ahoward@...>
Date: 2003-04-26T08:05:20+09:00
Subject: Re: Persistant data

On Sat, 26 Apr 2003, Matt Lawrence wrote:

> On Fri, 25 Apr 2003, Ryan Pavlik wrote:
>
> > If you can hang on for a day or so, I'll release Mephle on Monday.
> > I just added the ability to write non-networked apps a few nights ago,
> > along with a SQLite storage driver.
>
> Well, it sounds a bit complex, but I can certainly wait.  The big thing I
> want is to be able to say something like 'arr.push "foo"' and it will be
> persistant.

none too fast - but this will do it:

~/eg/ruby > cat pobject.rb
require 'pstore'

class PObject
  DEFAULT_STORE = File.basename($0) << '.pstore'

  attr :object

  def initialize key, pstore = PStore.new (DEFAULT_STORE)
    @key = key
    @pstore = pstore
    @object = nil

    @pstore.transaction do
      @object = @pstore[@key] rescue nil
    end

    @object ||= yield
  end

  def method_missing (method, *args, &block)
    @object.send (method, *args, &block)
    persist
  end

  def persist
    @pstore.transaction do
      @pstore[@key] = @object
    end
  end
end


~/eg/ruby > cat pobjectdemo.rb
#!/usr/bin/env ruby

require 'pobject'

a = PObject.new(:a) { Array.new  }
a << Time.now

a.each do |time|
  puts time
end


~/eg/ruby > pobjectdemo.rb
Fri Apr 25 22:48:37 GMT 2003

~/eg/ruby > pobjectdemo.rb
Fri Apr 25 22:48:37 GMT 2003
Fri Apr 25 22:48:39 GMT 2003

~/eg/ruby > pobjectdemo.rb
Fri Apr 25 22:48:37 GMT 2003
Fri Apr 25 22:48:39 GMT 2003
Fri Apr 25 22:48:40 GMT 2003


-a

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