Class: IOStreams::Tabular::Parser::Fixed

Inherits:
Base
  • Object
show all
Defined in:
lib/io_streams/tabular/parser/fixed.rb

Overview

Parsing and rendering fixed length data

Defined Under Namespace

Classes: FixedLayout

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#requires_header?

Constructor Details

#initialize(layout:) ⇒ Fixed

Returns [IOStreams::Tabular::Parser]

Parameters:

layout: [Array<Hash>]
  [
    {key: 'name',    size: 23 },
    {key: 'address', size: 40 },
    {key: 'zip',     size: 5 }
  ]



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# File 'lib/io_streams/tabular/parser/fixed.rb', line 17

def initialize(layout:)
  @fixed_layout = parse_layout(layout)
end

Instance Attribute Details

#fixed_layout ⇒ Object (readonly)

Returns the value of attribute fixed_layout.



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# File 'lib/io_streams/tabular/parser/fixed.rb', line 6

def fixed_layout
  @fixed_layout
end

Instance Method Details

#parse(line) ⇒ Object

Returns [Hash<Symbol, String>] fixed layout values extracted from the supplied line. String will be encoded to ‘encoding`



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# File 'lib/io_streams/tabular/parser/fixed.rb', line 37

def parse(line)
  unless line.is_a?(String)
    raise(IOStreams::Errors::TypeMismatch, "Format is :fixed. Invalid parse input: #{line.class.name}")
  end

  hash  = {}
  index = 0
  fixed_layout.each do |map|
    value         = line[index..(index + map.size - 1)]
    index         += map.size
    hash[map.key] = value.to_s.strip
  end
  hash
end

#render(row, header) ⇒ Object

Returns [String] fixed layout values extracted from the supplied hash. String will be encoded to ‘encoding`



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# File 'lib/io_streams/tabular/parser/fixed.rb', line 23

def render(row, header)
  hash = header.to_hash(row)

  result = ''
  fixed_layout.each do |map|
    # A nil value is considered an empty string
    value = hash[map.key].to_s
    result << format("%-#{map.size}.#{map.size}s", value)
  end
  result
end