Query the availability of required and optional libraries and gems with a nice interface.
- A nice API
gem install available
A simple example
source = Available.new do
requires :nokogiri, :haml
optional :textile
end
source.satisfied? # => true/false - whether all required dependencies could be loaded
source.has.nokogiri? # => true/false
source.has?(:nokogiri) # => same as above
source.need.nokogiri! # either returns true, or raises a LoadError
source.missing # => [#<Available::Dependency…>, …] - an array of missing dependencies
source.error(:nokogiri) # => nil/LoadError - the exception that occurred while loading nokogiri
source.errors # => [#<LoadError…>, …] an array of all errors that occurred while trying to require dependencies
A more complex example
source = Available.new do
requires rack_ssl: 'rack/ssl' # require differs from name
requires sqlite: gem('sqlite3-ruby', 'sqlite') # explicitely a gem, giving its name and the proper require
requires markdown: any_of(:maruku, :rdiscount, :bluecloth)
end
source.which(:markdown) # => an Available::Depencency
source.which(:markdown).name # => either :maruku, :rdiscount or :bluecloth
Of course you can combine those requires
source = Available.new do
requires :nokogiri,
:haml,
rack_ssl: 'rack/ssl',
sqlite: gem('sqlite3-ruby', 'sqlite'),
markdown: any_of(:maruku, :rdiscount, :bluecloth)
optional :textile
end
You can run the tests using ruby test/runner.rb (I prefer ruby -rturn test/runner.rb,
but that's your call). Using test/runner is not a requirement. but it makes things easier.
You can use this code under the {file:LICENSE.txt BSD-2-Clause License}, free of charge. If you need a different license, please ask the author.