Variable methods and accessors in Ruby
Yeah I am a lame PHP guy who hasn’t gotten too deeply into Ruby yet. ;)
In PHP I often use variable methods, for example:
$foo = new Foo(); $funcname = 'dynamic_method'; $foo->$funcname(); // Same as calling $foo->dynamic_method(); $varname = 'dynamic_accessor'; $foo->$varname = 'some value'; // Same as calling $foo->dynamic_accessor = 'some value';
Now, because Ruby does not prefix $ in front of variables, it is impossible to use variable methods the way we do in PHP.
I am sure for Ruby gurus it’s pretty obvious but for me, I just spent more than 30 minutes searching for an alternative other than evil eval, and I finally found one.
We use the PHP call_user_func and call_user_func_array equivalent in Ruby: send or __send__.
Luckily accessors in Ruby are methods, so we are able to use the send method for both methods and accessors.
For example we can set a variable accessor like this:
foo = Foo.new
funcname = 'dynamic_method'
foo.send "#{funcname}"
# same as calling foo.dynamic_method
varname = 'dynamic_accessor'
foo.send "#{varname}=", 'some value'
# same as calling foo.dynamic_accessor = 'some value'
I wish in future versions of Ruby, we can somehow assign accessor values the way we do in PHP. :)
