Class: DBF::Column

Inherits:
Object
  • Object
show all
Defined in:
lib/dbf/column.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, type, length, decimal) ⇒ Column

Returns a new instance of Column.

Raises:



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# File 'lib/dbf/column.rb', line 8

def initialize(name, type, length, decimal)
  raise ColumnLengthError, "field length must be greater than 0" unless length > 0
  @name, @type, @length, @decimal = strip_non_ascii_chars(name), type, length, decimal
end

Instance Attribute Details

#decimal ⇒ Object (readonly)

Returns the value of attribute decimal.



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# File 'lib/dbf/column.rb', line 6

def decimal
  @decimal
end

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/dbf/column.rb', line 6

def length
  @length
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/dbf/column.rb', line 6

def name
  @name
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/dbf/column.rb', line 6

def type
  @type
end

Instance Method Details

#decode_datetime(value) ⇒ Object 



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# File 'lib/dbf/column.rb', line 32

def decode_datetime(value)
  days, milliseconds = value.unpack('l2')
  hours = (milliseconds / MS_PER_HOUR).to_i
  minutes = ((milliseconds - (hours * MS_PER_HOUR)) / MS_PER_MINUTE).to_i
  seconds = ((milliseconds - (hours * MS_PER_HOUR) - (minutes * MS_PER_MINUTE)) / MS_PER_SECOND).to_i
  DateTime.jd(days, hours, minutes, seconds)
end

#schema_definition ⇒ Object 



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# File 'lib/dbf/column.rb', line 44

def schema_definition
  data_type = case type
  when "N" # number
    if decimal > 0
      ":float"
    else
      ":integer"
    end
  when "I" # integer
    ":integer"
  when "D" # date
    ":date"
  when "T" # datetime
    ":datetime"
  when "L" # boolean
    ":boolean"
  when "M" # memo
    ":text"
  else
    ":string, :limit => #{length}"
  end
  
  "\"#{name.underscore}\", #{data_type}\n"
end

#type_cast(value) ⇒ Object 



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# File 'lib/dbf/column.rb', line 13

def type_cast(value)
  value = value.is_a?(Array) ? value.first : value
  
  case type
  when 'N' # number
    decimal.zero? ? unpack_integer(value) : value.to_f
  when 'D' # date
    value.to_date unless value.blank?
  when 'L' # logical
    value.strip =~ /^(y|t)$/i ? true : false
  when 'I' # integer
    unpack_integer(value)
  when 'T' # datetime
    decode_datetime(value)
  else
    value.to_s.strip
  end
end

#unpack_integer(value) ⇒ Object 



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# File 'lib/dbf/column.rb', line 40

def unpack_integer(value)
  value.unpack('v').first.to_i
end