On Fri, Nov 6, 2009 at 7:50 AM, James F.
<[email protected]
wrote:
Ruby is a dynamic language, as David pointed out, you can always get
around
whatever someone does. I think the point isn’t so much to make it
impossible
for them to do something, but rather to make it clear how it was
anticipated
that it would be used. If they want to go so far as to override the
methods,
or perform instance_eval to get at the variable, then I’d take that as a
very deliberate effort, so due to their determination to get around your
design, I would just assume that they had a legitimate reason to do so,
or
at least if it blows up, they’ll have no cause to be upset with you for
it.
I don’t know how you are trying to use the class, that you feel the need
to
return an array that cannot be altered, but you could define methods
which
give this functionality without ever exposing the array itself,
something
like this:
consider defining methods to give the functionality you might want
without exposing the guts of your class to the world
class Configuration
def initialize() @dependencies = [] end
def add_dependency(d) @dependencies << d end
def each_dependency
@dependencies.each { |dep| yield dep }
end
end
config = Configuration.new
config.add_dependency :dependency1
config.add_dependency :dependency2
config.add_dependency :dependency3
config.each_dependency do |dependency|
puts "I am accessing #{dependency}, "
“without ever seeing the array.”
end
Of course, they can always get around whatever you have done,
in the above, there is no way to get at @dependencies from the
outside world, but in their code they could just add the code below
class Configuration
attr_accessor :dependencies
end
p config.dependencies
END
Ruby is not about strict rigid code, or forcing people to use it
a certain way, it is dynamic. You have made your intentions clear,
at this point, if the user is not satisfied with your intentions,
then you must trust them to know what is best for their needs.
Something like this will not occur by accident, they have quite
deliberately decided that they need to break the encapsulation.