Class: Fit4Ruby::FitMessageRecord

Inherits:
Object
  • Object
show all
Includes:
BDFieldNameTranslator
Defined in:
lib/fit4ruby/FitMessageRecord.rb

Overview

The FitMessageRecord models a part of the FIT file that contains the FIT message records. Each message record has a number, a local type and a set of data fields. The content of a FitMessageRecord is defined by the FitDefinition. This class is only used for reading data from a FIT file. For writing FIT message records, the class FitDataRecord and its decendents are used.

Constant Summary

Constants included from BDFieldNameTranslator

BDFieldNameTranslator::BD_DICT

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from BDFieldNameTranslator

#to_bd_field_name

Constructor Details

#initialize(definition) ⇒ FitMessageRecord

Returns a new instance of FitMessageRecord.



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# File 'lib/fit4ruby/FitMessageRecord.rb', line 35

def initialize(definition)
  @definition = definition
  @global_message_number = definition.global_message_number.snapshot

  if (@gfm = GlobalFitMessages[@global_message_number])
    @name = @gfm.name
  else
    @name = "message#{@global_message_number}"
    Log.debug { "Unknown global message number #{@global_message_number}" }
  end
  @message_record = produce(definition)
end

Instance Attribute Details

#global_message_number ⇒ Object (readonly)

Returns the value of attribute global_message_number.



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# File 'lib/fit4ruby/FitMessageRecord.rb', line 33

def global_message_number
  @global_message_number
end

#message_record ⇒ Object (readonly)

Returns the value of attribute message_record.



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# File 'lib/fit4ruby/FitMessageRecord.rb', line 33

def message_record
  @message_record
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/fit4ruby/FitMessageRecord.rb', line 33

def name
  @name
end

Instance Method Details

#read(io, entity, filter = nil, fields_dump = nil, fit_entity) ⇒ Object 



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# File 'lib/fit4ruby/FitMessageRecord.rb', line 48

def read(io, entity, filter = nil, fields_dump = nil, fit_entity)
  @message_record.read(io)

  if @name == 'file_id'
    # Caveat: 'type' is used as '_type' in BinData fields!
    unless (entity_type = @message_record['_type'].snapshot)
      Log.fatal "Corrupted FIT file: file_id record has no type definition"
    end
    entity.set_type(entity_type)
  end
  obj = entity.new_fit_data_record(@name)

  # It's important to ensure that alternative fields are processed after
  # the regular fields so that the decision field has already been set.
  sorted_fields = @definition.data_fields.sort do |f1, f2|
    f1alt = is_alt_field?(f1)
    f2alt = is_alt_field?(f2)
    f1alt == f2alt ?
      f1.field_definition_number.snapshot <=>
      f2.field_definition_number.snapshot :
      f1alt ? 1 : -1
  end

  sorted_fields.each do |field|
    value = @message_record[to_bd_field_name(field.name)].snapshot
    # Strings are null byte terminated. There may be more bytes in the
    # file, but we have to discard all bytes from the first null byte
    # onwards.
    if value.is_a?(String)
      if (null_byte = value.index("\0"))
        value = null_byte == 0 ? '' : value[0..(null_byte - 1)]
      end
      if value.empty?
        value = nil
      end
    end

    field_name, field_def = get_field_name_and_global_def(field, obj)
    obj.set(field_name, v = (field_def || field).to_machine(value)) if obj

    if filter && fields_dump &&
       (filter.field_names.nil? ||
        filter.field_names.include?(field_name)) &&
       !(((value.is_a?(String) &&
           (value.count(field.undefined_value.chr) == value.length)) ||
          value == field.undefined_value) && filter.ignore_undef)
      fields_dump << DumpedField.new(
        @global_message_number,
        field.field_definition_number.snapshot,
        field_name,
        field.type(true),
        (field_def ? field_def : field).to_s(value))
    end
  end

  @definition.developer_fields.each do |field|
    # Find the corresponding field description for the given developer and
    # field number.
    field_number = field.field_number.snapshot

    unless (field_description = field.find_field_definition)
      Log.error "There is no field definition for developer " +
        "#{field.developer_data_index} field #{field_number}"
      next
    end

    field_name = field_description.full_field_name(fit_entity)
    units = field_description.units
    type = field.type
    native_message_number = field_description.native_mesg_num
    native_field_number = field_description.native_field_num

    value = @message_record[field.name].snapshot
    value = nil if value == field.undefined_value

    obj.set(field_name, value) if obj

    if filter && fields_dump &&
       (filter.field_names.nil? ||
        filter.field_names.include?(field_name)) &&
       !(((value.respond_to?('count') &&
           (value.count(field.undefined_value) == value.length)) ||
          value == field.undefined_value) && filter.ignore_undef)
      fields_dump << DumpedField.new(
        native_message_number,
        256 * (1 + field.developer_data_index) + field_number,
        field_name, type, field.to_s(value))
    end
  end

  if @name == 'field_description'
    obj.create_global_definition(fit_entity)
  end
end