Class: ServiceOperation::Context

Inherits:
OpenStruct
  • Object
show all
Defined in:
lib/service_operation/context.rb

Overview

Context for an Operation

Constant Summary collapse

CALLER_NAME_REGEXP = 
/`(rescue in |)([^']*)'$/

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build(context = {}) ⇒ Object

Class Methods



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# File 'lib/service_operation/context.rb', line 14

def self.build(context = {})
  self === context ? context : new(context) # rubocop:disable Style/CaseEquality
end

Instance Method Details

#as_json(*args) ⇒ Object

Fixes stack loop issue with OpenStruct



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# File 'lib/service_operation/context.rb', line 24

def as_json(*args)
  to_h.as_json(*args)
end

#coerce_if(*klasses) ⇒ Object

Use in the Operation class to create eager loading objects:

Operation.call(record: 'something').record == <Model name='something'>

Examples:

def Operation#record
  context.coerce_if(Integer, String) { |name| Model.find_by_param(name) }
end


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# File 'lib/service_operation/context.rb', line 43

def coerce_if(*klasses)
  field = klasses.shift if klasses.first.is_a?(Symbol)
  field ||= caller(1..1).first[CALLER_NAME_REGEXP, 2] # method name fetch was called from
  self[field] = yield(self[field]) if klasses.any? { |k| self[field].is_a?(k) }
  self[field]
end

#fail!(context = {}) ⇒ Object

Raises:



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# File 'lib/service_operation/context.rb', line 28

def fail!(context = {})
  context.each { |k, v| send("#{k}=", v) }
  @failure = true

  raise Failure, self
end

#failure? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/service_operation/context.rb', line 106

def failure?
  @failure || false
end

#fetch(*args) ⇒ Object

Examples:

fetch(:field, 'value')
fetch(:field) { 'value' }

will infer field name from enclosing method name

def enclosing_method
  context.fetch { 'value' }
end
def enclosing_method
  context.fetch 'value'
end


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# File 'lib/service_operation/context.rb', line 62

def fetch(*args)
  if !block_given? && args.length == 1 # context.fetch 'value'
    new_value = args.first
  else
    field, new_value = args
  end

  field ||= caller(1..1).first[CALLER_NAME_REGEXP, 2] # method name fetch was called from

  # field is already set
  value = send(field)
  return value if value

  # context.fetch { block }
  if block_given?
    begin
      value ||= yield
    rescue StandardError => e
      # apply if this context to the field, if this is first instance of this error being raised
      self[field] = e.context if e.respond_to?(:context) &&
                                 e.context.is_a?(self.class) &&
                                 e.context != self &&
                                 e.context.not_yet_raised

      raise e
    end
  end

  value ||= new_value

  self[field] = value

  value
end

#not_yet_raised ⇒ true, false

Returns first call returns false, after that true.

Returns:

  • (true, false) —

    first call returns false, after that true.



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# File 'lib/service_operation/context.rb', line 98

def not_yet_raised
  if @already_raised
    false
  else
    @already_raised = true
  end
end

#success? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/service_operation/context.rb', line 110

def success?
  !failure?
end

#to_h(*args) ⇒ Object 



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# File 'lib/service_operation/context.rb', line 114

def to_h(*args)
  if args.any?
    super().slice(*args)
  else
    super()
  end
end