Class: CSVImporter

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

Constant Summary collapse

CURRENT_DIRECTORY = 
"./".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#headers_and_type ⇒ Object (readonly)

Returns the value of attribute headers_and_type.



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# File 'lib/csv_importer.rb', line 6

def headers_and_type
  @headers_and_type
end

#original_headers ⇒ Object (readonly)

Returns the value of attribute original_headers.



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# File 'lib/csv_importer.rb', line 6

def original_headers
  @original_headers
end

Instance Method Details

#convert_header_to_methodable_name(header, track_original: false) ⇒ Object 



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# File 'lib/csv_importer.rb', line 90

def convert_header_to_methodable_name(header, track_original: false)
  if track_original
    @original_headers ||= []
    @original_headers << header
  end

  header.downcase.gsub(/[^a-z]/, "_").to_sym
end

#create_pstore(csv, opts = {}, filename = SecureRandom.uuid) ⇒ Object 



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# File 'lib/csv_importer.rb', line 24

def create_pstore(csv, opts = {}, filename = SecureRandom.uuid)
  conversion_required = opts.fetch(:convert, [])
  if opts.fetch(:convert, nil) == :best_guess
    conversion_required = guess_conversion_types(csv)
  end

  csv_converters = conversion_required.map { |header, desired_format| CSVConverter.new(header => desired_format) }
  file_save_location = opts[:save_to_location] || CURRENT_DIRECTORY

  store = QueryablePStore.new("#{file_save_location}#{filename}.pstore")
  store.transaction do
    csv.each do |row|
      store[SecureRandom.uuid] = csv_converters.inject(row.to_h) { |hash, converter| converter.convert(hash) }
    end
  end

  if opts.fetch(:convert, nil) == :best_guess
    original_headers = @original_headers.clone

    original_headers.each do |original_header|
      @headers_and_type ||= {}
      @headers_and_type[original_header] = symbol_to_class(
        conversion_required[
          convert_header_to_methodable_name(original_header)
        ]
      )
    end
  else
    set_headers_and_type(@original_headers, store)
  end

  store
end

#guess_conversion_types(csv) ⇒ Object 



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# File 'lib/csv_importer.rb', line 71

def guess_conversion_types(csv)
  headers = csv.headers
  headers_and_type = {}

  csv.each do |row|
    headers.each do |header|
      if row[header].match(/\A(\d)+\z/) && (headers_and_type[header].nil? || headers_and_type[header] == :integer)
        headers_and_type[header] = :integer
      elsif row[header].match(/^\d*\.\d+$/) && (headers_and_type[header].nil? || headers_and_type[header] == :float)
        headers_and_type[header] = :float
      else
        headers_and_type[header] = :string
      end
    end
  end

  headers_and_type
end

#import_csv(filename, opts = {}) ⇒ Object 



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# File 'lib/csv_importer.rb', line 8

def import_csv(filename, opts = {})
  csv = CSV.read(File.open(filename), headers: true, header_converters: -> (header) { convert_header_to_methodable_name(header, track_original: true) })
  store = create_pstore(csv, opts, filename)
  store.csv_importer = self

  store
end

#import_csv_from_string(string, opts = {}) ⇒ Object 



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# File 'lib/csv_importer.rb', line 16

def import_csv_from_string(string, opts = {})
  csv = CSV.parse(string, headers: true, header_converters: -> (header) { convert_header_to_methodable_name(header, track_original: true) })
  store = create_pstore(csv, opts)
  store.csv_importer = self

  store
end

#symbol_to_class(symbol) ⇒ Object 



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# File 'lib/csv_importer.rb', line 58

def symbol_to_class(symbol)
  case symbol
  when :integer
    Integer
  when :float
    Float
  when :string
    String
  else
    raise "Unknown symbol: #{symbol}"
  end
end