State_Machine(s) Usage

Yay. Thanks Jason Seifer. That's got everything working just as it should.

Oppsss... My bad, in Gemfile you should keep: gem 'state_machines', and just follow from step no. 2.

I replaced gem 'state_machine' from the video with gem 'state_machines-activerecord'.

bundle install showed three new gems loaded:

Installing state_machines 0.4.0
Installing state_machines-activemodel 0.3.0
Installing state_machines-activerecord 0.3.0

Restart your rails server, of course.

Everything worked after that.

Here's what I've done so far for this lesson.

1. Add: gem 'state_machines' to Gemfile, and then run bundle.
2. Add new column (state) in account_entries table.
3. Modify account_entry.rb as follows:

class AccountEntry < ActiveRecord::Base
  belongs_to :account

  validates :account_id, presence: true
  validates_associated :account

  after_save :update_account_balance!

   state_machine :state, :initial => :submitted do
    event :approve do
      transition :submitted => :approved
    end

    event :reject do
      transition :submitted => :rejected
    end
  end

  def update_account_balance!
    account.update_balance!
  end

end

Following along with the lesson, I then fire up the server, visit http://localhost:3000/employees/2 and create a new time entry. A time entry is added, but it doesn't enter anything in the account_entries table for 'state'.

If I remove the state_machine code from account_entry.rb then the entries in the 'state' column will display. Otherwise they do not.

Is that all the code you require?

Hi Jason Seifer,

First up, how do I 'tag' you?

I'm now using state_machines-activerecord in my Gemfile, instead of 'state_machines', which I removed.

And now, when I access http://localhost:3000/employees/2 I get:

NoMethodError in Employees#show

Showing C:/Users/Matt/Websites/RubyOnRails/TestApp/biller2/app/views/employees/show.html.erb where line #4 raised:

undefined method `state_machine' for #<Class:0x876fd68>

Rails.root: C:/Users/Matt/Websites/RubyOnRails/TestApp/biller2 Application Trace | Framework Trace | Full Trace

app/models/account_entry.rb:9:in <class:AccountEntry>' app/models/account_entry.rb:1:in<top (required)>' app/models/time_entry.rb:1:in <top (required)>' app/views/employees/show.html.erb:4:inapp_views_employees_show_html_erb__507868244_71086140'

Here's my code for the relevant files:

account_entry.rb

class AccountEntry < ActiveRecord::Base
  belongs_to :account

  validates :account_id, presence: true
  validates_associated :account

  after_save :update_account_balance!

   state_machine :state, :initial => :submitted do
    event :approve do
      transition :submitted => :approved
    end

    event :reject do
      transition :submitted => :rejected
    end
  end

  def update_account_balance!
    account.update_balance!
  end

end

time_entry.rb

class TimeEntry < AccountEntry
  belongs_to :employee

  validates :time, numericality: {greter_than: 0, less_than: 24}

  before_create :calculate_amount!

  def self.per_hour
    100
  end

  def calculate_amount!
    self.amount = TimeEntry.per_hour * self.time
  end

end

show.html.erb

<h1><%= @employee.name %></h1>

<h3>Submit time form</h3>
<%= form_for [@employee, TimeEntry.new] do |f| %>
  <%= f.label :customer %>
  <%= f.collection_select(:account_id, Customer.premier.all, :id, :name) %>
  <%= f.label :time %>
  <%= f.text_field :time, :value => 1.0 %>
  <%= f.submit %>
<% end %>

<h3>Time Entries</h3>

<% @employee.time_entries.each do |entry| %>
  <div class="entry">
    <strong><%= entry.state %></strong>
    <%= entry.time %>
    <%= entry.account.name %>
    <%= entry.created_at %>
  </div>
<% end %>

Thanks Jason. Here's my project zipped up: https://dl.dropboxusercontent.com/u/30757113/biller2.zip

Hi @jasonseifer,

My project can be downloaded here: https://dl.dropboxusercontent.com/u/30757113/biller2.zip