Module: DataShift::ColumnPacker

Includes:
Delimiters
Included in:
CSV, CsvExporter, ExcelExporter
Defined in:
lib/datashift/column_packer.rb

Instance Method Summary collapse

Methods included from Delimiters

attribute_list_end, attribute_list_end=, attribute_list_start, attribute_list_start=, column_delim, csv_delim, csv_delim=, eol, key_value_sep, key_value_sep=, multi_assoc_delim, multi_facet_delim, multi_value_delim, name_value_delim, set_column_delim, set_csv_delim, set_multi_assoc_delim, set_multi_value_delim, set_name_value_delim, setmulti_facet_delim, #text_delim, #text_delim=

Instance Method Details

#escape_for_csv(value) ⇒ Object

Ensure a value is written to CSV correctly TODO - better ways ?? - see transcoding and String#encode



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# File 'lib/datashift/column_packer.rb', line 25

def escape_for_csv(value)
  text = value.to_s.gsub(text_delim, escape_text_delim()).gsub("\n", "\\n")

  text = "#{text_delim}#{text}#{text_delim}" if(text.include?(Delimiters::csv_delim))
  text
end

#escape_text_delim ⇒ Object

Return opposite of text delim - “hello, ‘barry’” => ‘“hello, ”barry“”’



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# File 'lib/datashift/column_packer.rb', line 16

def escape_text_delim
  return '"' if text_delim == "\'"
  "\'"
end

#record_to_column(record, options = {}) ⇒ Object

Convert an AR instance to a single column

e.g User  :  ":name = > 'tom', :role => 'developer'"

OPTIONS

with_only  Specify (as symbols) columns for association types to export
json:         Export association data in single column in JSON format



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# File 'lib/datashift/column_packer.rb', line 70

def record_to_column(record, options = {})

  return "" if(record.nil? || (record.respond_to?(:each) && record.empty?) )

  with_only = *options[:with_only] ? [*options[:with_only]] : nil

  return record.to_json if(options[:json] && !with_only) # packs associations into single column

  if( record.respond_to?(:each) )

    return "" if(record.empty?)

    data = []

    record.each { |r| data << record_to_column(r, options); }

    if(options[:json])
      return data.to_json
    else
      return "#{data.join(Delimiters::multi_assoc_delim)}"
    end

  else

    data = options[:json] ? {} : []

    record.serializable_hash.each do |name, value|
      next if(with_only && !with_only.include?( name.to_sym ) )

      if(options[:json])
        data[name] = value
      else
        data << "#{name.to_sym} #{Delimiters::key_value_sep} #{value.to_s.gsub(text_delim, escape_text_delim)}"
      end
    end

    if(options[:json])#
      return data.to_json
    else
      "#{Delimiters::attribute_list_start}#{data.join(Delimiters::multi_value_delim)}#{Delimiters::attribute_list_end}"
    end

  end

end

#record_to_csv(record, options = {}) ⇒ Object

Convert an AR instance to a set of CSV columns



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# File 'lib/datashift/column_packer.rb', line 118

def record_to_csv(record, options = {})
  csv_data = record.serializable_hash.values.collect { |value| escape_for_csv(value) }

  [*options[:methods]].each { |x| csv_data << escape_for_csv(record.send(x)) if(record.respond_to?(x)) } if(options[:methods])

  csv_data.join( Delimiters::csv_delim )
end

#to_headers(records, associations = nil, options = {}) ⇒ Object 



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# File 'lib/datashift/column_packer.rb', line 33

def to_headers( records, associations = nil, options = {} )
  return if( !records.first.is_a?(ActiveRecord::Base) || records.empty?)

  only = *options[:only] ? [*options[:only]] : nil

  headers =[]

  if associations
    details_mgr = DataShift::MethodDictionary.method_details_mgrs[records.first.class]

    [*associations].each do |a|

      details_mgr.get_list(a).each do  |md|

        next if(only && !only.include?( md.name.to_sym ) )

        headers << "#{md.operator}"

      end
    end if(details_mgr)

  else

    headers = records.first.class.columns.collect( &:name )
  end

  headers
end