Class: Jsoning::Mapper

Inherits:
Object
  • Object
show all
Defined in:
lib/jsoning/foundations/mapper.rb

Overview

responsible of mapping from object to representable values, one field at a time

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(version_instance) ⇒ Mapper 



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# File 'lib/jsoning/foundations/mapper.rb', line 15

def initialize(version_instance)
  self.parallel_variable = nil
  @default_value = nil
  self.nullable = true
  self.version = version_instance
end

Instance Attribute Details

#default_value(version_name = self.version.version_name) ⇒ Object 



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# File 'lib/jsoning/foundations/mapper.rb', line 63

def default_value(version_name = self.version.version_name)
  if @default_value
    if @default_value.is_a?(Proc)
      return deep_parse(@default_value.(), version_name, true)
    else
      return deep_parse(@default_value, version_name, true)
    end
  else
    nil
  end
end

#name ⇒ Object 



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# File 'lib/jsoning/foundations/mapper.rb', line 31

def name
  @name_as_string = @name.to_s if @name_as_string.nil?
  @name_as_string
end

#nullable=(value) ⇒ Object (writeonly)

Sets the attribute nullable



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# File 'lib/jsoning/foundations/mapper.rb', line 10

def nullable=(value)
  @nullable = value
end

#parallel_variable ⇒ Object

what variable in the object will be used to obtain the value



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# File 'lib/jsoning/foundations/mapper.rb', line 12

def parallel_variable
  @parallel_variable
end

#value_processor ⇒ Object

Returns the value of attribute value_processor.



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# File 'lib/jsoning/foundations/mapper.rb', line 13

def value_processor
  @value_processor
end

#version ⇒ Object

access to a version instance



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# File 'lib/jsoning/foundations/mapper.rb', line 4

def version
  @version
end

Instance Method Details

#extract(object, requested_version_name, target_hash) ⇒ Object

map this very specific object’s field to target_hash



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# File 'lib/jsoning/foundations/mapper.rb', line 37

def extract(object, requested_version_name, target_hash)
  target_value = nil

  if object.respond_to?(parallel_variable)
    parallel_val = object.send(parallel_variable)
    target_value = parallel_val
  end

  if target_value.nil?
    target_value = self.default_value(requested_version_name)
    if target_value.nil? && !self.nullable?
      raise Jsoning::Error, "Null value given for '#{name}' when serializing #{object}"
    end
  end

  # apply extractor to extracted value, if processor is defined
  if value_processor
    target_value = deep_parse(target_value, requested_version_name, false)
    target_value = value_processor.(target_value)
  else
    target_value = deep_parse(target_value, requested_version_name, true)
  end

  target_hash[name] = target_value
end

#nullable? ⇒ Boolean 



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# File 'lib/jsoning/foundations/mapper.rb', line 22

def nullable?
  if @nullable.is_a?(TrueClass) || @nullable.is_a?(FalseClass)
    return @nullable
  else
    # by default, allow every mapped things to be nil
    true
  end
end