I'm trying to make a finite state machine chain with AASM gem. I want to check if a string is unique (not existing in the database).
I wrote:
require 'rubygems'
require 'aasm'
class Term
include AASM
aasm do
state :Beginning, :initial => true
state :CheckUniqueness
def initialize(term)
print term
end
event :UniquenessChecking do
print "Check uniqueness"
transitions :from => :Beginning, :to => :CheckUniqueness
end
end
end
term = Term.new("textstring")
term.CheckUniqueness
But when I use Term.new("textstring"), it doesn't allow me to pass a parameter I think, because I get a error:
`initialize': wrong number of arguments (1 for 0) (ArgumentError)
from try.rb:24:in `new'
from try.rb:24:in `<main>'
Is it possible to pass a parameter with init in AASM? I would like to know how I can do that?
You defined initialize inside of the aasm block, just move it out of that block:
require 'rubygems'
require 'aasm'
class Term
include AASM
def initialize(term)
print term
end
aasm do
# ...
end
end
Related
This question probably has a simple answer but I can't find any examples for using Roda with RSpec3, so it is difficult to troubleshoot.
I am using Marston and Dees "Effective Testing w/ RSpec3" book which uses Sinatra instead of Roda. I am having difficulty passing an object to API.new, and, from the book, this is what works with Sinatra but fails with a "wrong number of arguments" error when I substitute Roda.
Depending on whether I pass arguments with super or no arguments with super(), the error switches to indicate that the failure occurs either at the initialize method or in the call to Rack::Test::Methods post in the spec.
I see that in Rack::Test, in the Github repo README, I may have to use Rack::Builder.parse_file("config.ru") but that didn't help.
Here are the two errors that rspec shows when using super without brackets:
Failures:
1) MbrTrak::API POST /users when the user is successfully recorded returns the user id
Failure/Error: post '/users', JSON.generate(user)
ArgumentError:
wrong number of arguments (given 1, expected 0)
# ./spec/unit/app/api_spec.rb:21:in `block (4 levels) in <module:MbrTrak>'
And when using super():
1) MbrTrak::API POST /users when the user is successfully recorded returns the user id
Failure/Error: super()
ArgumentError:
wrong number of arguments (given 0, expected 1)
# ./app/api.rb:8:in `initialize'
# ./spec/unit/app/api_spec.rb:10:in `new'
# ./spec/unit/app/api_spec.rb:10:in `app'
# ./spec/unit/app/api_spec.rb:21:in `block (4 levels) in <module:MbrTrak>'
This is my api_spec.rb:
require_relative '../../../app/api'
require 'rack/test'
module MbrTrak
RecordResult = Struct.new(:success?, :expense_id, :error_message)
RSpec.describe API do
include Rack::Test::Methods
def app
API.new(directory: directory)
end
let(:directory) { instance_double('MbrTrak::Directory')}
describe 'POST /users' do
context 'when the user is successfully recorded' do
it 'returns the user id' do
user = { 'some' => 'user' }
allow(directory).to receive(:record)
.with(user)
.and_return(RecordResult.new(true, 417, nil))
post '/users', JSON.generate(user)
parsed = JSON.parse(last_response.body)
expect(parsed).to include('user_id' => 417)
end
end
end
end
end
And here is my api.rb file:
require 'roda'
require 'json'
module MbrTrak
class API < Roda
def initialize(directory: Directory.new)
#directory = directory
super()
end
plugin :render, escape: true
plugin :json
route do |r|
r.on "users" do
r.is Integer do |id|
r.get do
JSON.generate([])
end
end
r.post do
user = JSON.parse(request.body.read)
result = #directory.record(user)
JSON.generate('user_id' => result.user_id)
end
end
end
end
end
My config.ru is:
require "./app/api"
run MbrTrak::API
Well roda has defined initialize method that receives env as an argument which is being called by the app method of the class. Looks atm like this
def self.app
...
lambda{|env| new(env)._roda_handle_main_route}
...
end
And the constructor of the app looks like this
def initialize(env)
When you run your config.ru with run MbrTrack::API you are actually invoking the call method of the roda class which looks like this
def self.call(env)
app.call(env)
end
Because you have redefined the constructor to accept hash positional argument this no longer works and it throws the error you are receiving
ArgumentError:
wrong number of arguments (given 0, expected 1)
Now what problem are you trying to solve, if you want to make your API class configurable one way to go is to try out dry-configurable which is part of the great dry-ruby gem collection.
If you want to do something else feel free to ask.
It has been a long time since you posted your question so hope you will still find this helpful.
I'm attempting to use the Geocoder gem with a DataMapper model in a Sinatra application.
environment.rb:
require 'rubygems'
require 'bundler/setup'
require 'dm-core'
require 'dm-timestamps'
require 'dm-validations'
require 'dm-aggregates'
require 'dm-migrations'
require 'dm-types'
require 'geocoder'
require 'sinatra' unless defined?(Sinatra)
# load models
$LOAD_PATH.unshift("#{File.dirname(__FILE__)}/lib")
Dir.glob("#{File.dirname(__FILE__)}/lib/*.rb") { |lib| require File.basename(lib, '.*') }
DataMapper.setup(:default, (ENV["DATABASE_URL"] || "sqlite3:///#{File.expand_path(File.dirname(__FILE__))}/#{Sinatra::Base.environment}.db"))
DataMapper.finalize
DataMapper.auto_upgrade!
lib/location.rb:
class Location
include DataMapper::Resource
include Geocoder::Model::Base
property :id, Serial
property :address, String, :required => true
# geocoder gem
geocoded_by :address, :latitude => :lat, :longitude => :lng
# geocoder
after_validation :geocode, :if => :address_changed?
end
When I attempt to start an IRB session, an exception is generated:
irb> require './environment'
NameError: uninitialized constant Geocoder::Model
...
What am I not understanding?
First up, it looks like the Geocode gem won't have direct support for Datamapper, as per this issue.
Second, when you include a module inside a class, the methods are available to the instance of the class, and not at the class level. For example:
module Name
def name
puts "Module"
end
end
class SomeClass
include Name
end
SomeClass.new.name # => "Module"
This works because when you include a module, that module gets added to the ancestor chain of that class. Any methods that get sent to the instance which are not available on the instance are forwarded to the ancestors. However, there's another method called extend which adds the methods at a class-level rather than at instance level:
# module definition same as before
class SomeClass
extend Name
name # works!
end
Inorder to get class-level inclusion, there is another way (which is what the Geocoder gem uses for supported models:
# module code same as before
module Name
def name
puts "Module"
end
def self.included(klass)
klass.extend(self)
end
end
The included hook is provided for models which can be overridden to do something when the include Name step executes. Since there's no Datamapper specific module that is not executing this step, you see that error.
So, I'm trying to build a quick console program for my development needs, akin to rails console (I'm using Sinatra + DataMapper + pry).
I run it and launch cat = Category.new(name: 'TestCat', type: :referential). It gives me the following error:
Error: Cannot open "/home/art-solopov/Projects/by-language/Ruby/billy-bones/=" for reading.
What could be the cause of the problem?
console:
#!/usr/bin/env ruby
$LOAD_PATH << 'lib'
require 'pry'
require 'config'
binding.pry
lib/config.rb:
# Configuration files and app-wide requires go here
require 'sinatra'
require 'data_mapper'
require 'model/bill'
require 'model/category'
configure :production do
DataMapper::Logger.new('db-log', :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones')
DataMapper.finalize
end
configure :development do
DataMapper::Logger.new($stderr, :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones-dev')
DataMapper.finalize
DataMapper.auto_upgrade!
end
configure :test do
require 'dm_migrations'
DataMapper::Logger.new($stderr, :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones-test')
DataMapper.finalize
DataMapper.auto_migrate!
end
lib/model/category.rb:
require 'data_mapper'
class Category
include DataMapper::Resource
property :id, Serial
property :name, String
property :type, Enum[:referential, :predefined, :computable]
has n, :bills
# has n, :tariffs TODO uncomment when tariff ready
def create_bill(params)
# A bill factory for current category type
case type
when :referential
ReferentialBill.new params
when :predefined
PredefinedBill.new params
when :computable
ComputableBill.new params
end
end
end
If I substitute pry with irb in the console script, it goes fine.
Thank you very much!
P. S.
Okay, yesterday I tried this script again, and it worked perfectly. I didn't change anything. I'm not sure whether I should remove the question now or not.
P. P. S.
Or actually not... Today I've encountered it again. Still completely oblivious to what could cause it.
** SOLVED **
DAMN YOU PRY!
Okay, so here's the difference.
When I tested it the second time, I actually entered a = Category.new(name: 'TestCat', type: :referential) and it worked. Looks like pry just thinks cat is a Unix command, not a valid variable name.
Not answer to the pry question I just generally hate case statements in ruby.
Why not change:
def create_bill(params)
# A bill factory for current category type
case type
when :referential
ReferentialBill.new params
when :predefined
PredefinedBill.new params
when :computable
ComputableBill.new params
end
end
to:
def create_bill(params)
# A bill factory for current category type
self.send("new_#{type}_bill",params)
end
def new_referential_bill(params)
ReferentialBill.new params
end
def new_predefined_bill(params)
PredefinedBill.new params
end
def new_computable_bill(params)
ComputableBill.new params
end
You could make this more dynamic but I think that would take away from readability in this case but if you'd like in rails this should do the trick
def create_bill(params)
if [:referential, :predefined, :computable].include?(type)
"#{type}_bill".classify.constantize.new(params)
else
#Some Kind of Handling for non Defined Bill Types
end
end
Or this will work inside or outside rails
def create_bill(params)
if [:referential, :predefined, :computable].include?(type)
Object.const_get("#{type.to_s.capitalize}Bill").new(params)
else
#Some Kind of Handling for non Defined Bill Types
end
end
I have the HTTParty gem on my system and I can use it from within rails.
Now I want to use it standalone.
I am trying:
class Stuff
include HTTParty
def self.y
HTTParty.get('http://www.google.com')
end
end
Stuff.y
but I get
$ ruby test_httparty.rb
test_httparty.rb:2:in `<class:Stuff>': uninitialized constant Stuff::HTTParty (NameError)
from test_httparty.rb:1:in `<main>'
07:46:52 durrantm Castle2012 /home/durrantm/Dropnot/_/rails_apps/linker 73845718_get_method
$
You have to require 'httparty':
require 'httparty'
class Stuff
include HTTParty
# ...
end
Its all because of the include which exists with in the class
If you include a class with a module, that means you're "bringing in" the module's methods as instance methods.
If you need more clarity on include and require
I request you to refer to this wonderful SO Posting
What is the difference between include and require in Ruby?
Here is an example which I have taken from the same posting
module A
def say
puts "this is module A"
end
end
class B
include A
end
class C
extend A
end
B.say => undefined method 'say' for B:Class
B.new.say => this is module A
C.say => this is module A
C.new.say => undefined method 'say' for C:Class
I've got a class in a program which is handling game states. I'm actually handling it with AASM so to create an event I have to use something like aasm_event :name ... inside the class.
I need to be able to load other files who dynamically have to add events and states to the class.
How is it possible ?
Thank you in advance.
The following should work, unless aasm_state and aasm_event are protected or private:
# game.rb
class Game
include AASM
aasm_initial_state :start
end
# add the require after the class definition, else it will complain of a missing constant
require "other_file"
# other_file.rb
Game.aasm_state :another_state
Game.aasm_event do
transitions :to => :another_state, :from => [:start]
end