Contents

class RemoteTable
  class Transform
    attr_accessor :select, :reject, :transform_class, :transform_options, :transform, :raw_table
    attr_accessor :errata
    
    def initialize(bus)
      if transform_params = bus.delete(:transform)
        @transform_class = transform_params.delete(:class)
        @transform_options = transform_params
        @transform = @transform_class.new(@transform_options)
        @transform.add_hints!(bus)
      end
      @select = bus[:select]
      @reject = bus[:reject]
      @errata = bus[:errata]
    end
    
    # the null transformation
    def apply(raw_table)
      self.raw_table = raw_table
      self
    end
    
    # - convert it to a plain hash for whatever ruby version you're on
    # - dump it
    # - digest it
    def self.row_hash(row)
      plain_hsh = if RUBY_VERSION >= '1.9'
        row.keys.sort.inject(::Hash.new) do |memo, key|
          value = row[key]
          key = key.to_s.toutf8
          value = value.to_s.toutf8 if value.respond_to? :to_s
          memo[key] = value
          memo
        end
      else
        ::Hash.new.replace(row)
      end
      ::Digest::MD5.hexdigest ::Marshal.dump(plain_hsh)
    end
    
    def each_row(&block)
      raw_table.each_row do |row|
        row['row_hash'] = self.class.row_hash(row)
        virtual_rows = transform ? transform.apply(row) : row # allow transform.apply(row) to return multiple rows
        Array.wrap(virtual_rows).each do |virtual_row|
          if errata
            next if errata.rejects? virtual_row
            errata.correct! virtual_row
          end
          next if select and !select.call(virtual_row)
          next if reject and reject.call(virtual_row)
          yield virtual_row
        end
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
remote_table-0.2.32	lib/remote_table/transform.rb
remote_table-0.2.31	lib/remote_table/transform.rb