Class: CaTissue::Extractor

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/catissue/extract/extractor.rb

Overview

Extracts caTissue objects.

Constant Summary collapse

DEF_NAME =

The default name of this migrator.

'caTissue Extractor'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Extractor

Creates a new Extractor with the given options.

Parameters:

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

    a customizable set of options

Options Hash (options):

  • :file (String) —

    the extract configuration file name

  • :name (String) —

    name of this Migrator (default is caTissue Migrator)

  • :output (String) —

    optional output CSV file name

  • :target (String) —

    required target domain class or class name

  • :ids (String) —

    the database identifiers of the target objects to extract

  • :log (String) —

    log file (default log/extract.log)

Raises:

  • (ArgumentError) 


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# File 'lib/catissue/extract/extractor.rb', line 24

def initialize(options={})
  conf_file = options.delete(:file)
  if conf_file then
    CaRuby::Properties.new(conf_file, :array => [:shims]).each { |key, value| options[key.to_sym] ||= value }
  end
  # tailor the options
  name = options[:name] || DEF_NAME
  super(name)
  @ids = options[:ids]
  raise ArgumentError.new("Missing required ids option") unless @ids
  # convert the required target to a CaTissue class if necessary
  @target = target_class_from_option(options[:target])
  @target ||= CaTissue::Specimen
  # the CSV output file
  @output = options[:output]
  raise ArgumentError.new("Missing required extract output file option") unless @output
  # the field mapping configuration
  fld_conf = options[:mapping]
  mapper = CaRuby::CsvMapper.new(fld_conf, @target, @output, :mode => "w")
  @csvio = mapper.csvio
  @fld_path_hash = {}
  mapper.paths.each do |path|
    fld = mapper.header(path)
    # the path node is either an attribute symbol or attribute metadata;
    # if metadata, then use the reader method.
    @fld_path_hash[fld] = path.map { |attr_or_md| CaRuby::AttributeMetadata === attr_or_md ? attr_or_md.reader : attr_or_md }
  end
  logger.debug { "Extract field => path map: #{@fld_path_hash.transform { |path| path.join('.') }.pp_s}" }
end

Instance Attribute Details

#output ⇒ Object (readonly)

The extract output file



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# File 'lib/catissue/extract/extractor.rb', line 14

def output
  @output
end

Instance Method Details

#extract ⇒ Object Also known as: each

Executes this extractor CSV file and calls the block given to this method on each target domain object.



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# File 'lib/catissue/extract/extractor.rb', line 64

def extract
  logger.debug { "Found #{@ids.size} extract targets." }
  CaTissue::Database.instance.open do
    @ids.each do |identifier|
      obj = @target.new(:identifier => identifier)
      logger.debug { "Finding extract target #{obj}..." }
      if obj.find then
        logger.debug { "Extractor fetched #{obj}." }
        yield obj
      else
        logger.debug { "Extract target #{obj} not found." }
      end
    end
  end
end

#run ⇒ Object

Exports the selected target records from the database to the output file.



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# File 'lib/catissue/extract/extractor.rb', line 55

def run
  begin
    extract { |obj| write(obj) }
  ensure
    @csvio.close
  end
end