Class: FileProcessor::CSV

Inherits:
SimpleDelegator
  • Object
show all
Includes:
Enumerable
Defined in:
lib/file_processor/csv.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename, options = {}) ⇒ CSV

Returns a new instance of CSV.



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# File 'lib/file_processor/csv.rb', line 22

def initialize(filename, options={})
  @gzipped      = options.delete(:gzipped)

  load(filename, options.delete(:open_options))

  @options      = default_options.merge(options)

  @options[:encoding] ||= detect_encoding
  @detected_encoding  ||= Encoding.find(@options[:encoding])

  tempfile.reopen(detected_mode) if tempfile.closed?

  @options[:col_sep]  ||= detect_column_separator

  super(::CSV.new(tempfile, @options))
end

Instance Attribute Details

#detected_encoding ⇒ Object

Returns the value of attribute detected_encoding.



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# File 'lib/file_processor/csv.rb', line 20

def detected_encoding
  @detected_encoding
end

Class Method Details

.open(*args) ⇒ Object

Opens a file and yields it, ensuring that it is properly closed.



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# File 'lib/file_processor/csv.rb', line 6

def self.open(*args)
  instance = new(*args)

  if block_given?
    begin
      yield instance
    ensure
      instance.close if instance
    end
  else
    instance
  end
end

Instance Method Details

#each ⇒ Object

Yields each row of the data source in turn, skipping blanks and rows with no data.

Support for Enumerable.

The data source must be open for reading.



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# File 'lib/file_processor/csv.rb', line 56

def each
  if block_given?
    while row = shift
      yield row unless skip_blanks? && row_with_no_data?(row)
    end
  else
    to_enum
  end
end

#gzipped? ⇒ Boolean

Returns true when the file is gzipped, false otherwise

Returns:

  • (Boolean) 


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# File 'lib/file_processor/csv.rb', line 97

def gzipped?
  @gzipped
end

#process_range(options = {}) ⇒ Enumerable

Process a range of lines in the CSV file.

Examples:

Process 1000 lines starting from the line 2000

csv.process_range(offset: 2000, limit: 1000) do |row, index|
  # process range here
end

Parameters:

  • options (Hash) (defaults to: {}) —

    A hash with offset and/or limit

Options Hash (options):

  • :offset (Integer) —

    The offset from which the process should start

  • :limit (Integer) —

    The number of rows to process

Returns:

  • (Enumerable) —

    CSV’s enumerable



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# File 'lib/file_processor/csv.rb', line 79

def process_range(options={})
  options ||= {}

  offset = options[:offset] || 0
  limit  = options[:limit]  || -1

  rewind
  each_with_index do |row, index|
    next if index < offset
    break if limit >= 0 && index >= offset + limit

    yield row, index
  end
ensure
  rewind
end

#total_count(&block) ⇒ Integer

Counts the number of rows in the file, even if it has already been read

Returns:

  • (Integer) —

    the number of rows in the file



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# File 'lib/file_processor/csv.rb', line 42

def total_count(&block)
  rewind
  count(&block)
ensure
  rewind
end