MachineTag
MachineTag is a Ruby library for using machine tags like those used on Flickr and RightScale.
Installation
Add this line to your application's Gemfile:
gem 'machine_tag'
And then execute:
$ bundle
Or install it yourself as:
$ gem install machine_tag
Usage
MachineTag provides two classes for dealing with machine tags and tags in general: MachineTag::Tag
and MachineTag::Set:
MachineTag::Tag
The MachineTag::Tag class represents a tag which can either be a machine tag or a plain tag. It inherits from String so it can be used in the same ways.
plain_tag = MachineTag::Tag.new('geotagged')
plain_tag == 'geotagged' # => true
plain_tag.machine_tag? # => false
machine_tag = MachineTag::Tag.new('geo:lat=34.4348067')
machine_tag == 'geo:lat=34.4348067' # => true
machine_tag.machine_tag? # => true
machine_tag.namespace # => "geo"
machine_tag.predicate # => "lat"
machine_tag.namespace_and_predicate # => "geo:lat"
machine_tag.value.to_f # => 34.4348067
machine_tag = MachineTag::Tag.machine_tag('geo', 'lon', -119.8016962)
machine_tag == 'geo:lon=-119.8016962' # => true
machine_tag.machine_tag? # => trueMachineTag::Set
The MachineTag::Set class represents a set of tags and provides a way of looking them up by
namespace or by namespace and predicate. It inherits from the Set so it can be used in the same
ways. If String objects are passed into it they will automatically be converted to
MachineTag::Tag objects.
tags = MachineTag::Set['geotagged', 'geo:lat=34.4348067', 'geo:lon=-119.8016962']
tags.include?('geotagged') # => true
tags.plain_tags # => #<Set: {"geotagged"}>
tags.machine_tags # => #<Set: {"geo:lat=34.4348067", "geo:lon=-119.8016962"}>
tags['geo'] # => #<Set: {"geo:lat=34.4348067", "geo:lon=-119.8016962"}>
tags['geo:lat'] # => #<Set: {"geo:lat=34.4348067"}>
tags['geo', 'lon'] # => #<Set: {"geo:lon=-119.8016962"}>
tags[/^geo:(lat|lon)$/] # => #<Set: {"geo:lat=34.4348067", "geo:lon=-119.8016962"}>More information can be found in the documentation.
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request