Dynamic Setters

Rails
1

Hello all,

I’m tinkering around with method_missing, and have run into a problem.

I’m trying to create virtual columns so plugins like formtastic work
properly with this model.

I plan on wrapping all attributes related to this project with the
name “option_*”, as such I have changed method missing to the
following:

…
def method_missing(method, *arguments, &block)
logger.info “Looking for #{method}”
if method.to_s =~ /option_(.+)/
process_option_method(method, *arguments)
else
super
end
end
def process_option_method(method, *arguments)
if method.to_s =~ /option_(.+)=/
return set_option($1, *arguments.first)
elsif method.to_s =~ /option_(.+)/
return get_option($1, false)
end
end
…

now get_option and set_option work as expected, and the setter part of
the above code also works. However when a form is submitted with a
field option_foo i get the error “unknown attribute: option_foo”.

The logger input above indicates that method_missing is not called,
and the stack trace confirms this. The stack trace indicates that when
update_attributes is called, it never gets around to method missing.

So, I’m stuck. What would be the proper way to accomplish a dynamic
setter method?

Brian

2

Solved my own problem…

for anyone else with the same issue, update_attributes cheks to see if
the attribute exists by querying responds_to?(attr_name)

It was necessary to overload that method to get it working. On to the
next problem.

Brian