Skip to content
Filter Chain is a Ruby gem for processing data through a chain of filters in an object oriented style.
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
bin
lib
test
.gitignore
.travis.yml
Gemfile
LICENSE.txt
README.md
Rakefile
filter_chain.gemspec

README.md

Filter Chain Build Status Coverage Status

Filter Chain is a Ruby gem for processing data through a chain of filters in an object oriented style.

Installation

Add this line to your application's Gemfile:

gem "filter_chain"

And then execute:

$ bundle

Or install it yourself as:

$ gem install filter_chain

Chains

A Chain is a container for a set of filters.

The below example serializes each input object to a JSON string, compresses the strings, prints the byte size of each string, and collects the results for future retrieval:

chain = FilterChain::Chain.new { |c|
  c.add(FilterChain::SerializeFilter.new(:format => :json))

  c.add(FilterChain::DeflateFilter.new)

  c.add(FilterChain::ProcFilter.new { |data|
    puts "Byte size: #{data.bytesize}"
    data
  })

  c.add(FilterChain::Collector.new)
}

chain << "Hello world"
chain << "How are you?"

puts chain.output.inspect

Filters

A Filter is an object that takes an input and passes it's output to the next link in a chain of filters. A number of filters are pre-defined:

  • DeflateFilter
  • InflateFilter
  • SerializeFilter
  • DeserializeFilter
  • MultiplexFilter
  • DemultiplexFilter
  • ProcFilter
  • Collector
  • Terminator

You can easily create your own filters by inheriting from the Filter class and overriding the following handlers:

  • on_initialize
  • on_input(data)

You pass data to the next filter by calling the pass method in your on_input method.

Collectors

A Collector is a specialized filter designed to be the last link in a chain. An array based collector is included, but you can easily define custom collectors using other data structures.

Terminators

A Terminator takes the place of a collector when you want your last link to run a block of code.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/chadrem/filter_chain.

License

The gem is available as open source under the terms of the MIT License.

You can’t perform that action at this time.