Module: BusinessFlow::DSL::ClassMethods

Defined in:
lib/business_flow/dsl.rb

Overview

Contains the DSL for BusinessFlow

Defined Under Namespace

Classes: Inputs

Instance Method Summary collapse

Instance Method Details

#build(parameter_object) ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 118

def build(parameter_object)
  finalize_initializer
  allocate.tap do |flow|
    catch(:halt_step) do
      flow.send(:_business_flow_dsl_initialize, parameter_object)
    end
  end
end

#call(parameter_object = {}) ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 105

def call(parameter_object = {})
  flow = build(parameter_object)
  return result_from(flow) if flow.errors?
  execute(flow)
end

#call!(*args) ⇒ Object

Raises:



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# File 'lib/business_flow/dsl.rb', line 127

def call!(*args)
  flow = call(*args)
  raise FlowFailedException, flow if flow.errors?
  flow
end

#execute(flow) ⇒ Object

:reek:UtilityFunction This is a function on us so that other modules can change execution behavior.



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# File 'lib/business_flow/dsl.rb', line 113

def execute(flow)
  catch(:halt_step) { flow.call } unless flow.errors?
  result_from(flow)
end

#finalize_initializer ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 175

def finalize_initializer
  return if @finalized_initializer
  class_eval %{
    private def _business_flow_dsl_initialize(parameter_object)
      @parameter_object = parameter_object
      #{needs_code}
      initialize
    end
  }, __FILE__, __LINE__ - 6
  @finalized_initializer = true
end

#finalize_result_provider ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 159

def finalize_result_provider
  return if @finalized_result_provider || !@result_copy
  const_get(:Result).class_eval "#{@result_copy}\nend", __FILE__, __LINE__
  @finalized_result_provider = true
end

#inputs ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 74

def inputs
  @inputs ||= Inputs.new(self)
end

#instrument(_name, _flow) {|nil| ... } ⇒ Object

Yields:

  • (nil) 


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# File 'lib/business_flow/dsl.rb', line 145

def instrument(_name, _flow)
  yield nil
end

#lookup(field, by:, with:) ⇒ Object

Provides an alternate way to look up the value for a field. This can be thought of as using a ‘wants’ combined with an expectation of presence, without having to check for whether or not the wants can be executed.

:reek:NilCheck This is one of the places where we eliminate nil.



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# File 'lib/business_flow/dsl.rb', line 59

def lookup(field, by:, with:)
  by = Array.wrap(by)
  optional(*by)
  wants field, with, unless: -> { by.any? { |input| send(input).nil? } },
                     default_output: field
end

#needs(*fields) ⇒ Object

Requires that a field be retrievable from the initialization parameters

This will only require that the field is not nil. The field may still be #empty?



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# File 'lib/business_flow/dsl.rb', line 44

def needs(*fields)
  inputs.add_needs(fields)
end

#needs_code ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 165

def needs_code
  needs.map do |need|
    %(if #{need}.nil?
        errors.add(:#{need}, :invalid, message: 'must not be nil')
        throw :halt_step
      end
    )
  end.join("\n")
end

#optional(*fields) ⇒ Object

Allows a field to be retieved form the initialization paramters, but does not require it to be non-nil



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# File 'lib/business_flow/dsl.rb', line 50

def optional(*fields)
  inputs.add_optional(fields)
end

#provides(*fields) ⇒ Object

Declares that you will expose a field to the outside world.



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# File 'lib/business_flow/dsl.rb', line 79

def provides(*fields)
  @provides ||= FieldList.new([], PublicField, [self, const_get(:Result)])
  @result_copy ||= FROM_FLOW_PREAMBLE
  @result_copy += fields.map { |field| "\n@#{field} = flow.#{field}" }
                        .join
  @provides.add_fields(fields)
end

#result_from(flow) ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 149

def result_from(flow)
  finalize_result_provider unless @finalized_result_provider
  # We use instance_variable_get here instead of making it part of
  # from_flow to ensure that we do not create the errors object unless
  # we need it.
  result = const_get(:Result).new(flow.instance_variable_get(:@errors))
  result.from_flow(flow) if @result_copy
  result
end

#step(klass, opts = {}, &blk) ⇒ Object

:reek:ControlParameter It’s just nicer to have this fall back to a block than have a different DSL method when using/not using blocks



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# File 'lib/business_flow/dsl.rb', line 98

def step(klass, opts = {}, &blk)
  step = Step.new(Callable.new(blk || klass), opts)
  step_queue.push(step)
  step.output_fields
      .each { |field| Field.new(field).add_to(self) }
end

#step_executor(executor_class = nil) ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 137

def step_executor(executor_class = nil)
  if executor_class
    @executor_class = executor_class
  else
    @executor_class ||= ::BusinessFlow::DefaultStepExecutor
  end
end

#step_queue ⇒ Object 



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# File 'lib/business_flow/dsl.rb', line 133

def step_queue
  @step_queue ||= []
end

#uses(field, klass = nil, opts = {}, &blk) ⇒ Object

:reek:ControlParameter It’s just nicer to have this fall back to a block than have a different DSL method when using/not using blocks



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# File 'lib/business_flow/dsl.rb', line 89

def uses(field, klass = nil, opts = {}, &blk)
  step = Step.new(Callable.new(klass || blk),
                  { default_output: field }.merge(opts))
  retriever = proc { step.call(self).merge_into(self) }
  UsesField.new(field, retriever).add_to(self)
end

#wants(field, default = nil, opts = {}, &blk) ⇒ Object

Allows a field to be retrieved from the initialiaztion parameters



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# File 'lib/business_flow/dsl.rb', line 67

def wants(field, default = nil, opts = {}, &blk)
  internal_name = "wants_#{field}".to_sym
  default = proc { nil } unless default || block_given?
  uses(internal_name, default, opts, &blk)
  inputs.add_wants(ParameterField.new(field, internal_name))
end