Question

I’ve just started writing a reasonably straightforward site using sinatra. My problem is that I wanted to refactor the main app.rb file but am getting errors trying to access the url params.

In my get ‘/’ action, Sinatra’s looking at which params are set and then needs to do a few different things depending on what’s in the url. Something like this.

class App < Sinatra::Application
  ...
  get '/' do
    if params['code1']
      @network = 'code1'
      mode code here
    elsif params['called'] && params['mac']
      @network = 'code2'
      mode code here
    elsif params['code3']
      @network = 'code3'
      mode code here
    end  
  end      

The problem is that I need to require a file that also uses the params.

I’ve put the following in the above code:

require File.dirname(__FILE__) + '/lib/networks/code1.rb'

Where code1.rb includes:

class App < Sinatra::Application
  if params['login']  # == 'login'
    pass = 'uampass'
  elsif
  ...

But that gives me the following error:

undefined local variable or method `params' for main:Object

How can I refactor this without causing an error

Answer 1

As far as i know you can’t use two (or more) Sinatra applications in, well one application. Since both files define a Sinatra::Application descendant this isn’t possible.

Also if you want to use values from the params-hash you should define helper methods Helper Documentation, which you call when processing the route, or you just create Class which has class or instance methods which take params-values as parameters. Actually calling params from another file/class doesn’t seem like good practice.

To put this in context: Sinatra applications are organised as handlers. The Sinatra::Application descendant is something like the main handler which uses support methods(helpers and instance methods of the Sinatra::Application descendant) or support Classes, which are usually defined in other files, but do not descend from Sinatra::Application.

To make this a little bit more clearly:

Your main Sinatra file:

require_relative 'another_file.rb'
class App < Sinatra::Application
  # ...
  @a_handler = MyHandler.new
  get '/' do

    if params['something'] == 'wanted_value'
      @a_handler.handle_it(params)
    end

end

Another file (‘another_file.rb’):

class MyHandler
  def initialize
    @an_instance_variable = 'foobar'
  end
  def handle_it(params_hash)
    if params_hash['login']  # == 'login'
      pass = 'uampass'
    elsif
     # ...
    end
    # ...
    # do some stuff
    # ....
    return pass
  end
end

Actual code would of course depend on the real problem you’re trying to solve, so if you would elaborate i could be more precise…