Rails no-brainer?

I've been using Rails for about 4 years and have often wondered why it doesn't implement the following concept; a Rails controller could define a method like:

def mymethod(a, b)
end

and if you invoked the method with mymethod&a=14&b=hi that Rails would automatically set the variable "a'" to "14" and "b" to "hi".

Right now, you have to write methods like:

def mymethods
  a = params[:a]
  b = params[:b]
  ...
end 

Does anyone have any insight into why Rails doesn't support this?

Comments

[Damian]

Perhaps surprisingly ruby has no means to get parameter names.

Merb (presumably to achieve what you describe here) has 'action-args'. The implementation is quite exciting, one for each of jruby, mri and 1.9.

http://merbivore.com/documentation/1.0.6.1/doc/rdoc/merb-action-args-1.0/index.html

[intertwingly.net/blog]

I don't believe that Ruby itself provides the necessary function to do this: if you get access to a method, you can determine its "arity" but not the names of arguments.

The closest you could come is something like this:

action :mymethods, [:a, :b] do
end

For bonus points, the action method could define the necessary route.

[Graham Glass]

According to this, there are a few ways to get method names via reflection:

http://stackoverflow.com/questions/622324/getting-argument-names-in-ruby-reflection

Perhaps this is something new in Ruby 1.9?

[Robert W. Oliver II]

This might show Rails's heritage from a fed-up PHP developer. Having to set the variables from the param[] array might help prevent against security attacks and trying to chase down order-of-insertion bugs.