From: jney <jeansebastien.ney@...>
Date: 2010-10-24T05:15:15+09:00
Subject: Re: No key set in openstruct ?

On Oct 23, 8:03 pm, Robert Klemme <shortcut...@googlemail.com> wrote:
> On 23.10.2010 19:16, jney wrote:
>
> >    Is there a cleaner way to check if no field have been set than the
> > following code ?
>
> >>>> o = OpenStruct.new
> > =>  #<OpenStruct>
> >>>> o.inspect == "#<OpenStruct>"
> > =>  true
> >>>> o.one_field = true
> > =>  true
> >>>> o.inspect == "#<OpenStruct>"
> > =>  false
> >>>> o.delete_field 'one_field'
> > =>  nil
> >>>> o.inspect == "#<OpenStruct>"
> > =>  true
>
> I'd consider this a tad cleaner - although it is not really rock solid:
>
> irb(main):015:0> x.methods - x.class.instance_methods
> => [:foo, :foo=]
> irb(main):016:0> x = OpenStruct.new
> => #<OpenStruct>
> irb(main):017:0> x.foo = 1
> => 1
> irb(main):018:0> x.methods - x.class.instance_methods
> => [:foo, :foo=]
>
> Kind regards
>
>         robert
>
> --
> remember.guy do |as, often| as.you_can - without endhttp://blog.rubybestpractices.com/

Thank you Robert.
The problem with this method is that the field definition is still
remaining even after delete :

>>> x = OpenStruct.new
=> #<OpenStruct>
>>> x.foo=1
=> 1
>>> x.methods - x.class.instance_methods
=> [:foo, :foo=]
>>> x.delete_field :foo
=> 1
>>> x.methods - x.class.instance_methods
=> [:foo, :foo=]