Module: Smash::CloudPowers::WorkflowFactory
- Included in:
- Smash::CloudPowers
- Defined in:
- lib/cloud_powers/workflow_factory.rb
Overview
The WorkflowFactory module provides you with a custom, embeddable workflow for classes. To do this, it takes a description of the workflow, in the form of a Hash
and injects it into the class’ Singleton/Eigan class. It uses the workflow
gem to handle the workflow stuff for now but after MVP, this will be a roll-our-own implementation, to cut down on all dependencies possible.
Instance Method Summary collapse
-
#inject_workflow(description) ⇒ Object
This is the method responsible for injecting the workflow on the instance it is called on.
Instance Method Details
#inject_workflow(description) ⇒ Object
This is the method responsible for injecting the workflow on the instance it is called on. After this method is called on an instance of some class, you can then access any of the described states as methods on that instance.
Parameters
-
description
Hash
- Describe the workflow you want to use. The format follows the actual Workflow Specification(s) from the gem that you would normally write onto the class like normal. -
Example
description
Hash
-
this description would give you a workflow that starts in the
new
state and when the#build!()
method was called on the object that has this workflow, the state would transition into thebuilding
state. The workflow would then listen for therun!()
method call, which would progress the state to thein_progress
state. Next, the workflow would listen for thepost_results!()
method call. When someone or something calls it, the state will progress to the final state,done
, from which no more workflow stuff will happen.description = {
workflow: { states: [ { new: { event: :build, transitions_to: :building } }, { building: { event: :run, transitions_to: :in_progress } }, { in_progress: { event: :post_results, transitions_to: :done } }, { done: nil } ] }
}
-
##Returns
-
nil
##Example
-
build the workflow using the description from above
class Job # code code code... def insert_my_workflow(description) class << build_workflow(description) end end
Which would yield this workflow, from the Workflow gem
class Job # all the commented lines below are what `WorkflowFactory#inject_workflow()` # did for you. These lines don't need to actually be in your class. # include Workflow # # workflow do # state :new do # event :build, :transitions_to => :building # end # state :building do # event :run, :transitions_to => :in_progress # end # state :in_progress do # event :post_results, :transitions_to => :done # end # state :done # end end job = Job.new # => #<Job:0x007fdaba8956b0> job.done? # => NoMethodError job.insert_workflow(description) # => nil job.done? # => false job.current_state # => :building
Notes
-
TODO: There has got to be a better way, so if any of you have suggestions… The fact that the eval gets evaluated and invoked in the workflow gem is of little comfort, despite how nice the gem is. Long story short, be comfortable with what you’re doing.
-
see the workflow gem docs and question me if you want some nice ways to really use this module. workflow homepage
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# File 'lib/cloud_powers/workflow_factory.rb', line 94 def inject_workflow(description) description_string_builder = ['include Workflow', 'workflow do'] description[:workflow][:states].each do |state| state.map do |name, state_description| if state_description.nil? # if this is a final state... description_string_builder << "state :#{name}" else # because it is not a final state, add event information too. description_string_builder.concat([ "state :#{name} do", "event :#{state_description[:event]}, transitions_to: :#{state_description[:transitions_to]}", "end" ]) end end end description_string_builder << "end\n" begin self.class.class_eval(description_string_builder.join("\n")) define_singleton_method(:has_workflow?) { true } rescue Exception => e define_singleton_method(:has_workflow?) { !!(puts e.backtrace) } end end |