Class: Chronicle::ETL::Extractor

Inherits:

Object

• Object
• Chronicle::ETL::Extractor

Extended by:

Registry::SelfRegistering

Includes:

Configurable

Defined in:

lib/chronicle/etl/extractors/extractor.rb

Overview

Abstract class representing an Extractor for an ETL job

Direct Known Subclasses

CSVExtractor, FileExtractor, JSONExtractor, StdinExtractor

Instance Attribute Summary

Attributes included from Registry::SelfRegistering

#connector_registration

Instance Method Summary

• #extract ⇒ Object

  Entrypoint for this Extractor.

• #initialize(options = {}) ⇒ Extractor constructor

  Construct a new instance of this extractor.

• #prepare ⇒ Object

  Hook called before #extract.

• #results_count ⇒ Object

  An optional method to calculate how many records there are to extract.

Methods included from Registry::SelfRegistering

register_connector

Methods included from Configurable

included

Constructor Details

#initialize(options = {}) ⇒ Extractor

Construct a new instance of this extractor. Options are passed in from a Runner == Parameters: options:: Options for configuring this Extractor

# File 'lib/chronicle/etl/extractors/extractor.rb', line 22

def initialize(options = {})
  apply_options(options)
end

Instance Method Details

#extract ⇒ Object

Entrypoint for this Extractor. Called by a Runner. Expects a series of records to be yielded

Raises:

• (NotImplementedError)

# File 'lib/chronicle/etl/extractors/extractor.rb', line 34

def extract
  raise NotImplementedError
end

#prepare ⇒ Object

Hook called before #extract. Useful for gathering data, initializing proxies, etc

# File 'lib/chronicle/etl/extractors/extractor.rb', line 27

def prepare; end

#results_count ⇒ Object

An optional method to calculate how many records there are to extract. Used primarily for building the progress bar

# File 'lib/chronicle/etl/extractors/extractor.rb', line 31

def results_count; end