From: Juston Davies <justondavies@...>
Date: 2009-07-08T03:36:36+09:00
Subject: Re: A define_method question

I can't seem to get Ruby2Ruby to work, and despite my efforts I can't
seem to find the documentation I need or any sort of tutorial. Is
there any other way to take a method from another object and store it
into a proc or lambda object?

On Jul 6, 2:47 pm, Juston <justondav...@gmail.com> wrote:
> That looks pretty sharp actually, after reading more about proc
> objects I think that may be the way to go. A lot cleaner than one
> giant define on a conglomerate string and a bit more flexible.
> Also, it looks like Ruby2Ruby and ParseTree (or ruby_parser) is going
> to help me get what I need from the "Modifier" objects too. I still
> need to do some more reading before I fully understand how to use it.
> If anyone has a good guide let me know, otherwise I'll hit the search
> engines.
>
> Thanks for the help and excellent input, this saves me a lot of time
> and headache!
>
> On Jul 6, 1:47 pm, Joel VanderWerf <vj...@path.berkeley.edu> wrote:
>
> > Juston wrote:
> > > I did think of that, and it's probably the route I wind up taking
> > > unwillingly. The problem is that if all the "Modifier" objects have
> > > their own unpredictable method names the host object doesn't know how
> > > to invoke them in its native (template) code.
>
> > > This will probably make more sense if I explain the context with a bit
> > > more dept (feel free to skip to the next paragraph.) I'm writing some
> > > automated testing software that will use Watir to interact with a
> > > browser dynamically, this stuff will be run nightly with no user
> > > present to direct it. The program builds a set of objects that define
> > > basic behavior from an input file filled with a problem-specific
> > > domain language. The fundamental objects are "TestSuite," "Test," ...
> > > "Step" and "Action." Any of these objects is subject to be changed by
> > > a "Modifier" that would alter the way the host object would say handle
> > > an error or record runtime or reset all children objects after its run
> > > etc. This means that most of the objects created during runtime are
> > > singletons in the sense that no two are ever really exactly the same,
> > > though they all come from the same templates. The further complicate
> > > the problem there are four basic types of modifiers that can be added
> > > at anytime: Ones that run before the template code executes, ones that
> > > run after the template code executes, ones that handle exceptions, and
> > > ones that run every time the host object becomes the focus of the
> > > stack. Modifiers are sporadically defined in the domain language (and
> > > subsequent ruby code module) added and removed without any regard to
> > > the underlying code, their presence is largely masked from the logic
> > > of the main system.
>
> > I'd still avoid eval-ing code and try to use data structures of procs,
> > something like this:
>
> > class Action
> >    def some_template
> >      before.each {|pr| pr.call(self)}
> >      puts "in template code"
> >      after.each {|pr| pr.call(self)}
> >    end
>
> >    def before
> >      @before ||= []
> >    end
>
> >    def after
> >      @after ||= []
> >    end
> > end
>
> > a = Action.new
> > a.before << proc {puts "before 1"}
> > a.before << proc {puts "before 2"}
> > a.after << proc {puts "after"}
>
> > a.some_template
>
> > --
> >        vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407
>
>