问题
I am facing a problem with usage of state_machine gem with my rails 4 app. A have a model which include a column call state as described in the provided rails tutorial http://gistflow.com/posts/679-state-machine-with-rails-basics
but when I define my state_machine as follows:
class Issue < ActiveRecord::Base
validates :title, :description, presence: true
has_many :notes
state_machine :initial => :new do
state :new, value: 0
state :analysed, value: 1
state :assigned, value: 2
state :inprogress, value: 3
state :inreview, value: 4
state :validation, value: 5
state :resolved, value: 6
state :cancelled, value: 7
state :closed, value: 8
state :rejected, value: 9
state :reopened, value: 10
end
def next
Issue.where("id > ?", self.id).first || Issue.first
end
def prev
Issue.where("id < ?", self.id).last || Issue.last
end
end
Here is my IssueConntroller
class IssuesController < ApplicationController
before_filter :find_issue, except: [:index, :new, :create]
def index
@issues = Issue.all
end
def new
@issue = Issue.new
end
def create
@issue = Issue.new(issue_params)
respond_to do |format|
if @issue.save
format.html {redirect_to @issue, :flash => { :success => "Issue succesfully created." } }
format.json {head :no_content}
else
format.html {render action: 'new'}
format.json { render json: @issue.errors, status: :unprocessable_entity }
end
end
end
def show
@note = Note.new
@note.issue_id = @issue.id
end
def edit
end
def update
respond_to do |format|
if @issue.update(issue_params)
format.html { redirect_to @issue, :flash => { :success => 'Issue was successfully updated.' }}
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: @issue.errors, status: :unprocessable_entity }
end
end
end
def destroy
@issue.destroy
flash[:error]= "Issue '#{@issue.title}' Deleted!"
redirect_to issues_path
end
private
def issue_params
params.require(:issue).permit(:title, :description)
end
def find_issue
@issue = Issue.find(params[:id])
end
end
I am falling into a undefined method `state_machine' for # NoMethodError in IssuesController#index. of course I have added gem 'state_machine line into my gemfile and run bundle install command. It seems like the gem is not loaded by the rails application...
Thank you for helping me out with this problem ;)
here is the trace
activerecord (4.0.0) lib/active_record/dynamic_matchers.rb:22:in `method_missing'
app/models/issue.rb:5:in `<class:Issue>'
app/models/issue.rb:1:in `<top (required)>'
activesupport (4.0.0) lib/active_support/dependencies.rb:423:in `load'
activesupport (4.0.0) lib/active_support/dependencies.rb:423:in `block in load_file'
activesupport (4.0.0) lib/active_support/dependencies.rb:615:in `new_constants_in'
activesupport (4.0.0) lib/active_support/dependencies.rb:422:in `load_file'
activesupport (4.0.0) lib/active_support/dependencies.rb:323:in `require_or_load'
activesupport (4.0.0) lib/active_support/dependencies.rb:462:in `load_missing_constant'
activesupport (4.0.0) lib/active_support/dependencies.rb:183:in `const_missing'
activesupport (4.0.0) lib/active_support/dependencies.rb:494:in `load_missing_constant'
activesupport (4.0.0) lib/active_support/dependencies.rb:183:in `const_missing'
app/controllers/issues_controller.rb:6:in `index'
actionpack (4.0.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.0) lib/active_support/callbacks.rb:413:in `_run__901873103026712443__process_action__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (4.0.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.0) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655:in `call'
rack (1.5.2) lib/rack/etag.rb:23:in `call'
rack (1.5.2) lib/rack/conditionalget.rb:25:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/flash.rb:241:in `call'
rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/cookies.rb:486:in `call'
activerecord (4.0.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__77618213725076532__call__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.0) li/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'b/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/application.rb:97:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/sebmac/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
回答1:
There is no problems in you code, try to reload SERVER after bundle , don't forget to add state:string or ìnteger since you use a value for state, to your model and of course same event
like
event :add_new do
transition new: :analysed
end
as a definition of state machine: is a transition form state to another
in rails c you can call some method for state machine
Issue.first.state_name
Issue.first.state_events
....
if you still have problem try to explain more :)
来源：https://stackoverflow.com/questions/18099290/state-machine-gem-integration-with-rails-4