Mechanize and MultiSelect fields

Mechanize is a little handy tool that allows you to perform all sorts of HTTP requests in Ruby. It automatically emulates all sorts of browsers, handles cookies, headers and stuff, which is really useful when you need to harvest some data from sites that don't have any computer friendly feeds.

I'm using it on my current project and run into a small problem. It doesn't work nicely with array data, like for example multiselect fields emulation, so when you do something like that

agent = Mechanize.new

agent.post('http://boo.boo/boo', {
  'param[]' => ['one', 'two', 'three']
});

In the reality it sends the 'one' value only. I've sent a little patch to the devs, but it seems like it will take time before they do something about it. So here is how you fix it in your rails app.

In any initializers in your `config/initializers/` directory add the following lines.

class Mechanize::Form::Field
  def query_value
    if @value.is_a?(Array)
      @value.collect{ |v| [@name, v || '']}
    else
      [[@name, @value || '']]
    end
  end
end

After that it will be just fine.