Contents

module ActiveRecordCSVImporter
  # Reads, sanitize and parse a CSV file
  class CSVReader
    include Virtus.model

    attribute :content, String
    attribute :file # IO
    attribute :path, String
    attribute :quote_char, String, default: '"'
    attribute :encoding, String, default: 'UTF-8'

    def csv_rows
      @csv_rows ||= begin
        sane_content = sanitize_content(read_content)
        separator = detect_separator(sane_content)
        cells = CSV.parse(
          sane_content,
          col_sep: separator,
          quote_char: quote_char,
          skip_blanks: true,
          encoding: encoding
        )
        sanitize_cells(cells)
      end
    end

    # Returns the header as an Array of Strings
    def header
      @header ||= csv_rows.first
    end

    # Returns the rows as an Array of Arrays of Strings
    def rows
      @rows ||= csv_rows[1..-1]
    end

    private

    def read_content
      if content
        content
      elsif file
        file.read
      elsif path
        File.open(path).read
      else
        raise Error, 'Please provide content, file, or path'
      end
    end

    def sanitize_content(csv_content)
      internal_encoding = encoding.split(':').last
      # Remove invalid byte sequences
      csv_content
        .encode(Encoding.find(internal_encoding), invalid: :replace, undef: :replace, replace: '')
        .gsub(/\r\r?\n?/, "\n") # Replaces windows line separators with "\n"
    end

    SEPARATORS = [',', ';', "\t"].freeze

    def detect_separator(csv_content)
      SEPARATORS.sort_by { |separator| csv_content.count(separator) }.last
    end

    # Remove trailing white spaces and ensure we always return a string
    def sanitize_cells(rows)
      rows.map do |cells|
        cells.map do |cell|
          cell ? cell.strip : ''
        end
      end
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
activerecord_csv_importer-0.4.0	lib/activerecord_csv_importer/csv_reader.rb
activerecord_csv_importer-0.3.0	lib/activerecord_csv_importer/csv_reader.rb
activerecord_csv_importer-0.2.3	lib/activerecord_csv_importer/csv_reader.rb