Module: Pretender::Methods

Defined in:
lib/pretender.rb

Instance Method Summary collapse

Instance Method Details

#impersonates(scope = :user, opts = {}) ⇒ Object 



11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
 
# File 'lib/pretender.rb', line 11

def impersonates(scope = :user, opts = {})
  impersonated_method = opts[:method] || :"current_#{scope}"
  impersonate_with = opts[:with] || proc { |id|
    klass = scope.to_s.classify.constantize
    primary_key = klass.respond_to?(:primary_key) ? klass.primary_key : :id
    klass.find_by(primary_key => id)
  }
  true_method = :"true_#{scope}"
  session_key = :"impersonated_#{scope}_id"
  impersonated_var = :"@impersonated_#{scope}"
  stop_impersonating_method = :"stop_impersonating_#{scope}"

  # define methods
  if method_defined?(impersonated_method) || private_method_defined?(impersonated_method)
    alias_method true_method, impersonated_method
  else
    sc = superclass
    define_method true_method do
      # TODO handle private methods
      raise Pretender::Error, "#{impersonated_method} must be defined before the impersonates method" unless sc.method_defined?(impersonated_method)
      sc.instance_method(impersonated_method).bind(self).call
    end
  end
  helper_method(true_method) if respond_to?(:helper_method)

  define_method impersonated_method do
    impersonated_resource = instance_variable_get(impersonated_var) if instance_variable_defined?(impersonated_var)

    if !impersonated_resource && request.session[session_key]
      # only fetch impersonation if user is logged in
      # this is a safety check (once per request) so
      # if a user logs out without session being destroyed
      # or stop_impersonating_user being called,
      # we can stop the impersonation
      if send(true_method)
        impersonated_resource = impersonate_with.call(request.session[session_key])
        instance_variable_set(impersonated_var, impersonated_resource) if impersonated_resource
      else
        # TODO better message
        warn "[pretender] Stopping impersonation due to safety check"
        send(stop_impersonating_method)
      end
    end

    impersonated_resource || send(true_method)
  end

  define_method :"impersonate_#{scope}" do |resource|
    raise ArgumentError, "No resource to impersonate" unless resource
    raise Pretender::Error, "Must be logged in to impersonate" unless send(true_method)

    instance_variable_set(impersonated_var, resource)
    # use to_s for Mongoid for BSON::ObjectId
    request.session[session_key] = resource.id.is_a?(Numeric) ? resource.id : resource.id.to_s
  end

  define_method stop_impersonating_method do
    remove_instance_variable(impersonated_var) if instance_variable_defined?(impersonated_var)
    request.session.delete(session_key)
  end
end