494 lines
22 KiB
Ruby
494 lines
22 KiB
Ruby
require 'active_support'
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require 'active_record'
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module ActiveRecord
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module Acts #:nodoc:
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module Taggable #:nodoc:
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def self.append_features(base)
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super
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base.extend(ClassMethods)
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end
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def self.split_tag_names(tags, separator)
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tag_names = []
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if tags.is_a?(Array)
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tag_names << tags
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elsif tags.is_a?(String)
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tag_names << (separator.is_a?(Proc) ? separator.call(tags) : tags.split(separator))
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end
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tag_names = tag_names.flatten.map { |name| name.strip }.uniq.compact #straight 'em up
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end
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# This mixin provides an easy way for addind tagging capabilities (also
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# known as folksnomy) to your active record objects. It allows you to add
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# tags to your objects as well as search for tagged objects.
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#
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# It assumes you are using a fully-normalized tagging database schema. For
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# that, you need a table (by default, named +tags+) to hold all tags in your
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# application and this table must have a primary key (normally a +id+ int
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# autonumber column) and a +name+ varchar column. You must also define a model class
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# related to this table (by default, named +Tag+).
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#
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# All tag names will be stored in this tags table. Taggable objects should reside
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# in their own tables, like any other object. Tagging objects is perfomed by
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# the +acts_as_taggable+ mixin using a +has_and_belong_to_many+ relationship that is
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# automatically created on the taggable class, and as so, a join table must exist
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# between the tags table and the taggable object table.
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#
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# The name of the join table, by default, always follow the form
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# '[tags_table_name]_[taggable_object_table_name]' even if the taggable object
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# table name precedes the tags table name alphabetically (for example, tags_photos).
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# This is different from the regular +has_and_belongs_to_many+ convention and
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# allows all your join tables to share a common prefix (which is the tags table name).
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#
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# The join table must be composed of the foreign keys from the tags table and the
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# taggable object table, so for instance, if we have a tags table named +tags+ (related
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# to a +Tag+ model) and a taggable +photos+ table (related to a +Photo+ model),
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# there should be a join table +tags_photos+ with int FK columns +photo_id+ and +tag_id+.
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# If you don<6F>t use a explicit full model related to the join table (thru the
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# +:join_class_name+ option), you must not add a primary key to the join table.
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#
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# The +acts_as_taggable+ adds the instance methods +tag+, +tag_names+,
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# +tag_names= +, +tag_names<< +, +tagged_with? + for adding tags to the object
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# and also the class method +find_tagged_with+ method for search tagged objects.
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#
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# Examples:
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#
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# class Photo < ActiveRecord::Base
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# # this creates a 'tags' collection, thru a has_and_belongs_to_many
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# # relationship that utilizes the join table 'tags_photos'.
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# acts_as_taggable
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# end
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#
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# photo = Photo.new
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#
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# # splits and adds to the tags collection
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# photo.tag "wine beer alcohol"
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#
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# # don't need to split since it's an array, but replaces the tags collection
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# # trailing and leading spaces are properly removed
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# photo.tag [ 'wine ', ' vodka'], :clear => true
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#
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# photo.tag_names # => [ 'wine', 'vodka' ]
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#
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# # appends new tags with a different separator
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# # the 'wine' tag won<6F>t be duplicated
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# photo.tag_names << 'wine, beer, alcohol', :separator => ','
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#
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# # The difference between +tag_names+ and +tags+ is that +tag_names+
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# # holds an array of String objects, mapped from +tags+, while +tags+
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# # holds the actual +has_and_belongs_to_many+ collection, and so, is
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# # composed of +Tag+ objects.
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# photo.tag_names.size # => 4
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# photo.tags.size # => 4
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#
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# # Find photos with 'wine' OR 'whisky'
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# Photo.find_tagged_with :any => [ 'wine', 'whisky' ]
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#
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# # Finds photos with 'wine' AND 'whisky' using a different separator.
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# # This is also known as tag combos.
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# Photo.find_tagged_with(:all => 'wine+whisky', :separator => '+'
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#
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# # Gets the top 10 tags for all photos
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# Photo.tags_count :limit => 10 # => { 'beer' => 68, 'wine' => 37, 'vodka' => '22', ... }
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#
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# # Gets the tags count that are greater than 30
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# Photo.tags_count :count => '> 30' # => { 'beer' => 68, 'wine' => 37 }
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#
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# You can also use full join models if you want to take advantage of
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# ActiveRecord<72>s callbacks, timestamping, inheritance and other features
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# on the join records as well. For that, you use the +:join_class_name+ option.
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# In this case, the join table must have a primary key.
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#
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# class Person
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# # This defines a class +TagPerson+ automagically.
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# acts_as_taggable :join_class_name => 'TagPerson'
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# end
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#
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# # We can open the +TagPerson+ class and add features to it.
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# class TagPerson
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# acts_as_list :scope => :person
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# belongs_to :created_by, :class_name => 'User', :foreign_key => 'created_by_id'
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# before_save :do_some_validation
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# after_save :do_some_stats
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# end
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#
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# # We can do some interesting things with it now
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# person = Person.new
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# person.tag "wine beer alcohol", :attributes => { :created_by_id => 1 }
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# Person.find_tagged_with(:any => 'wine', :condition => "tags_people.created_by_id = 1 AND tags_people.position = 1")
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module ClassMethods
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# This method defines a +has_and_belongs_to_many+ relationship between
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# the target class and the tag model class. It also adds several instance methods
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# for tagging objects of the target class, as well as a class method for searching
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# objects that contains specific tags.
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#
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# The options are:
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#
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# The +:collection+ parameter receives a symbol defining
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# the name of the tag collection method and it defaults to +:tags+.
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#
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# The +:tag_class_name+ parameter receives the tag model class name and
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# it defaults to +'Tag'+.
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#
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# THe +:join_class_name+ parameter receives the model class name that joins
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# the tag model and the taggable model. This automagically defines the join model
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# class that can be opened and extended.
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#
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# The remaining options are passed on to the +has_and_belongs_to_many+ declaration.
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# The +:join_table+ parameter is defined by default using the form
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# of '[tags_table_name]_[target_class_table_name]', example: +tags_photos+,
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# which differs from the standard +has_and_belongs_to_many+ behavior.
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def acts_as_taggable(options = {})
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options = { :collection => :tags, :tag_class_name => 'Tag' }.merge(options)
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collection_name = options[:collection]
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tag_model = options[:tag_class_name].constantize
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default_join_table = "#{tag_model.table_name}_#{self.table_name}"
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options[:join_table] ||= default_join_table
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options[:foreign_key] ||= self.name.to_s.foreign_key
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options[:association_foreign_key] ||= tag_model.to_s.foreign_key
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# not using a simple has_and_belongs_to_many but a full model
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# for joining the tags table and the taggable object table
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if join_class_name = options[:join_class_name]
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Object.class_eval "class #{join_class_name} < ActiveRecord::Base; set_table_name '#{options[:join_table]}' end" unless Object.const_defined?(join_class_name)
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join_model = join_class_name.constantize
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tagged = self
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join_model.class_eval do
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belongs_to :tag, :class_name => tag_model.to_s, :foreign_key => Inflector.foreign_key(tag_model.name)
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belongs_to :tagged, :class_name => tagged.name.to_s, :foreign_key => Inflector.foreign_key(tagged.name)
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define_method(:name) { self['name'] ||= tag.name }
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end
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options[:class_name] ||= join_model.to_s
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tag_pk, tag_fk = tag_model.primary_key, options[:association_foreign_key]
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t, jt = tag_model.table_name, join_model.table_name
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options[:finder_sql] ||= "SELECT #{jt}.*, #{t}.name AS name FROM #{jt}, #{t} WHERE #{jt}.#{tag_fk} = #{t}.#{tag_pk} AND #{jt}.#{options[:foreign_key]} = \#{quoted_id}"
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else
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join_model = nil
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end
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# set some class-wide attributes needed in class and instance methods
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write_inheritable_attribute(:tag_foreign_key, options[:association_foreign_key])
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write_inheritable_attribute(:taggable_foreign_key, options[:foreign_key])
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write_inheritable_attribute(:tag_collection_name, collection_name)
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write_inheritable_attribute(:tag_model, tag_model)
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write_inheritable_attribute(:tags_join_model, join_model)
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write_inheritable_attribute(:tags_join_table, options[:join_table])
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write_inheritable_attribute(:tag_options, options)
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[ :collection, :tag_class_name, :join_class_name ].each { |key| options.delete(key) } # remove these, we don't need it anymore
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[ :join_table, :association_foreign_key ].each { |key| options.delete(key) } if join_model # don<6F>t need this for has_many
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# now, finally add the proper relationships
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class_eval do
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include ActiveRecord::Acts::Taggable::InstanceMethods
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extend ActiveRecord::Acts::Taggable::SingletonMethods
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class_inheritable_reader :tag_collection_name, :tag_model, :tags_join_model,
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:tags_options, :tags_join_table,
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:tag_foreign_key, :taggable_foreign_key
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if join_model
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has_many collection_name, options
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else
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has_and_belongs_to_many collection_name, options
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end
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end
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end
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end
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module SingletonMethods
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# This method searches for objects of the taggable class and subclasses that
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# contains specific tags associated to them. The tags to be searched for can
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# be passed to the +:any+ or +:all+ options, either as a String or an Array.
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#
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# The options are:
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#
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# +:any+: searches objects that are related to ANY of the given tags
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#
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# +:all+: searcher objects that are related to ALL of the the given tags
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#
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# +:separator+: a string, regex or Proc object that will be used to split the
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# tags string passed to +:any+ or +:all+ using a regular +String#split+ method.
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# If a Proc is passed, the proc should split the string in any way it wants
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# and return an array of strings.
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#
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# +:conditions+: any additional conditions that should be appended to the
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# WHERE clause of the finder SQL. Just like regular +ActiveRecord::Base#find+ methods.
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#
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# +:order+: the same as used in regular +ActiveRecord::Base#find+ methods.
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#
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# +:limit+: the same as used in regular +ActiveRecord::Base#find+ methods.
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def find_tagged_with(options = {})
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options = { :separator => ' ' }.merge(options)
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tag_names = ActiveRecord::Acts::Taggable.split_tag_names(options[:any] || options[:all], options[:separator])
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raise "No tags were passed to :any or :all options" if tag_names.empty?
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o, o_pk, o_fk, t, t_pk, t_fk, jt = set_locals_for_sql
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sql = "SELECT DISTINCT #{o}.* FROM #{o}
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WHERE (SELECT COUNT(#{jt}.#{o_fk}) FROM #{jt}, #{t}
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WHERE #{jt}.#{t_fk} = #{t}.#{t_pk}
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AND #{jt}.#{o_fk} = #{o}.#{o_pk}
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AND (#{t}.name = #{tag_names.collect { |name| quote_value(name) }.join(" OR #{t}.name = ")}))"
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sql << (options[:all] ? " = #{tag_names.length}" : " > 0")
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sql << " AND #{sanitize_sql(options[:conditions])}" if options[:conditions]
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sql << " ORDER BY #{options[:order]} " if options[:order]
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add_limit!(sql, options)
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find_by_sql(sql)
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end
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# This method counts the number of times the tags have been applied to your objects
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# and, by default, returns a hash in the form of { 'tag_name' => count, ... }
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#
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# The options are:
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#
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# +:raw+: If you just want to get the raw output of the SQL statement (Array of Hashes), instead of the regular tags count Hash, set this to +true+.
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#
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# +:conditions+: any additional conditions that should be appended to the
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# WHERE clause of the SQL. Just like in regular +ActiveRecord::Base#find+ methods.
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#
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# +:order+: The same as used in +ActiveRecord::Base#find+ methods. By default, this is 'count DESC'.
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#
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# +:count+: Adds a HAVING clause to the SQL statement, where you can set conditions for the 'count' column. For example: '> 50'
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#
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# +:limit+: the same as used in regular +ActiveRecord::Base#find+ methods.
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def tags_count(options = {})
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options = {:order => 'count DESC'}.merge(options)
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o, o_pk, o_fk, t, t_pk, t_fk, jt = set_locals_for_sql
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sql = "SELECT #{t}.#{t_pk} AS id, #{t}.name AS name, COUNT(*) AS count FROM #{jt}, #{o}, #{t} WHERE #{jt}.#{t_fk} = #{t}.#{t_pk}
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AND #{jt}.#{o_fk} = #{o}.#{o_pk}"
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sql << " AND #{sanitize_sql(options[:conditions])}" if options[:conditions]
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sql << " GROUP BY #{t}.name, #{t}.#{t_pk}"
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sql << " HAVING COUNT(*) #{options[:count]} " if options[:count]
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sql << " ORDER BY #{options[:order]} " if options[:order]
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add_limit!(sql, options)
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result = connection.select_all(sql)
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count = result.inject({}) { |hsh, row| hsh[row['name']] = row['count'].to_i; hsh } unless options[:raw]
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count || result
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end
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# Alias for +tags_count+
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alias_method :tag_count, :tags_count
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def count_tagged_with(options = {})
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options = { :separator => ' ' }.merge(options)
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tag_names = ActiveRecord::Acts::Taggable.split_tag_names(options[:any] || options[:all], options[:separator])
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raise "No tags were passed to :any or :all options" if tag_names.empty?
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o, o_pk, o_fk, t, t_pk, t_fk, jt = set_locals_for_sql
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sql = "SELECT COUNT(*) count_all FROM #{jt}, #{o}, #{t} WHERE #{jt}.#{t_fk} = #{t}.#{t_pk}"
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sql << " AND ("
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sql << tag_names.collect {|tag| sanitize_sql( ["#{t}.name = ?",tag])}.join(" OR ")
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sql << ")"
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sql << " AND #{o}.#{o_pk} = #{jt}.#{o_fk}"
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sql << " AND #{sanitize_sql(options[:conditions])}" if options[:conditions]
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result = connection.select_all(sql)
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result[0]["count_all"].to_i
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end
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# Finds other records that share the most tags with the record passed
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# as the +related+ parameter. Useful for constructing 'Related' or
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# 'See Also' boxes and lists.
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#
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# The options are:
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#
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# +:limit+: defaults to 5, which means the method will return the top 5 records
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# that share the greatest number of tags with the passed one.
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def find_related_tagged(related, options = {})
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related_id = related.is_a?(self) ? related.id : related
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options = { :limit => 5 }.merge(options)
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o, o_pk, o_fk, t, t_pk, t_fk, jt = set_locals_for_sql
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sql = "SELECT o.*,
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(SELECT COUNT(jt2.#{o_fk}) FROM #{jt} jt, #{t} t, #{jt} jt2
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WHERE jt.#{o_fk} = #{related_id} AND t.#{t_pk} = jt.#{t_fk}
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AND jt2.#{o_fk} != jt.#{o_fk}
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AND jt2.#{t_fk} = jt.#{t_fk} AND o.#{o_pk} = jt2.#{o_fk}) AS count
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FROM #{o} o
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ORDER BY count DESC, o.#{o_pk} ASC"
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add_limit!(sql, options)
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find_by_sql(sql)
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end
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# Finds other tags that are related to the tags passed thru the +tags+
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# parameter, by finding common records that share similar sets of tags.
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# Useful for constructing 'Related tags' lists.
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#
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# The options are:
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#
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# +:separator+ => defines the separator (String or Regex) used to split
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# the tags parameter and defaults to ' ' (space and line breaks).
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#
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# +:raw+: If you just want to get the raw output of the SQL statement (Array of Hashes), instead of the regular tags count Hash, set this to +true+.
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#
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# +:limit+: the same as used in regular +ActiveRecord::Base#find+ methods.
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def find_related_tags(tags, options = {})
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tag_names = ActiveRecord::Acts::Taggable.split_tag_names(tags, options[:separator])
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o, o_pk, o_fk, t, t_pk, t_fk, jt = set_locals_for_sql
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sql = "SELECT jt.#{o_fk} AS o_id FROM #{jt} jt, #{t} t
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WHERE jt.#{t_fk} = t.#{t_pk}"
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sql << " AND (t.name IN ( "
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sql << quote_bound_value(tag_names)
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sql << ")) "
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sql << "GROUP BY jt.#{o_fk}
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HAVING COUNT(jt.#{o_fk}) = #{tag_names.length}"
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o_ids = connection.select_all(sql).map { |row| row['o_id'] }
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return options[:raw] ? [] : {} if o_ids.length < 1
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sql = "SELECT t.#{t_pk} AS id, t.name AS name, COUNT(jt.#{o_fk}) AS count FROM #{jt} jt, #{t} t
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WHERE jt.#{o_fk} IN (#{o_ids.join(",")})
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AND t.#{t_pk} = jt.#{t_fk}
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GROUP BY t.#{t_pk}, t.name, jt.#{t_fk}
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ORDER BY count DESC"
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add_limit!(sql, options)
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result = connection.select_all(sql).delete_if { |row| tag_names.include?(row['name']) }
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count = result.inject({}) { |hsh, row| hsh[row['name']] = row['count'].to_i; hsh } unless options[:raw]
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count || result
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end
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private
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def set_locals_for_sql
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[ table_name, primary_key, taggable_foreign_key,
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tag_model.table_name, tag_model.primary_key, tag_foreign_key,
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tags_join_model ? tags_join_model.table_name : tags_join_table ]
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end
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end
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module InstanceMethods
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# This method applies tags to the target object, by parsing the tags parameter
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# into Tag object instances and adding them to the tag collection of the object.
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# If the tag name already exists in the tags table, it just adds a relationship
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# to the existing tag record. If it doesn't exist, it then creates a new
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# Tag record for it.
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#
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# The +tags+ parameter can be a +String+, +Array+ or a +Proc+ object.
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# If it's a +String+, it's splitted using the +:separator+ specified in
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# the +options+ hash. If it's an +Array+ it is flattened and compacted.
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# Duplicate entries will be removed as well. Tag names are also stripped
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# of trailing and leading whitespaces. If a Proc is passed,
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# the proc should split the string in any way it wants and return an array of strings.
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#
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# The +options+ hash has the following parameters:
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#
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# +:separator+ => defines the separator (String or Regex) used to split
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# the tags parameter and defaults to ' ' (space and line breaks).
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#
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# +:clear+ => defines whether the existing tag collection will be cleared before
|
||
# applying the new +tags+ passed. Defaults to +false+.
|
||
def tag(tags, options = {})
|
||
|
||
options = { :separator => ' ', :clear => false }.merge(options)
|
||
attributes = options[:attributes] || {}
|
||
|
||
# parse the tags parameter
|
||
tag_names = ActiveRecord::Acts::Taggable.split_tag_names(tags, options[:separator])
|
||
|
||
# clear the collection if appropriate
|
||
tag_collection.clear if options[:clear]
|
||
|
||
# append the tag names to the collection
|
||
tag_names.each do |name|
|
||
# ensure that tag names don't get duplicated
|
||
tag_record = tag_model.find_by_name(name) || tag_model.new(:name => name)
|
||
if tags_join_model
|
||
tag_join_record = tags_join_model.new(attributes)
|
||
tag_join_record.tag = tag_record
|
||
tag_join_record.tagged = self
|
||
tag_collection << tag_join_record unless tagged_with?(name)
|
||
else
|
||
unless tagged_with?(name)
|
||
tag_record.attributes = attributes
|
||
tag_collection << tag_record
|
||
end
|
||
# tag_collection.push_with_attributes(tag_record, attributes) unless tagged_with?(name)
|
||
end
|
||
end
|
||
|
||
end
|
||
|
||
# Clears the current tags collection and sets the tag names for this object.
|
||
# Equivalent of calling #tag(..., :clear => true)
|
||
#
|
||
# Another way of appending tags to a existing tags collection is by using
|
||
# the +<<+ or +concat+ method on +tag_names+, which is equivalent of calling
|
||
# #tag(..., :clear => false).
|
||
def tag_names=(tags, options = {})
|
||
tag(tags, options.merge(:clear => true))
|
||
end
|
||
|
||
# Returns an array of strings containing the tags applied to this object.
|
||
# If +reload+ is +true+, the tags collection is reloaded.
|
||
def tag_names(reload = false)
|
||
ary = tag_collection(reload).map { |tag| tag.name }
|
||
ary.extend(TagNamesMixin)
|
||
ary.set_tag_container(self)
|
||
ary
|
||
end
|
||
|
||
# Checks to see if this object has been tagged with +tag_name+.
|
||
# If +reload+ is true, reloads the tag collection before doing the check.
|
||
def tagged_with?(tag_name, reload = false)
|
||
tag_names(reload).include?(tag_name)
|
||
end
|
||
|
||
# Calls +find_related_tagged+ passing +self+ as the +related+ parameter.
|
||
def tagged_related(options = {})
|
||
self.class.find_related_tagged(self.id, options)
|
||
end
|
||
|
||
private
|
||
def tag_model
|
||
self.class.tag_model
|
||
end
|
||
|
||
def tag_collection(reload = false)
|
||
send(self.class.tag_collection_name, reload)
|
||
end
|
||
|
||
def tags_join_model
|
||
self.class.tags_join_model
|
||
end
|
||
|
||
end
|
||
|
||
module TagNamesMixin #:nodoc:
|
||
|
||
def set_tag_container(tag_container)
|
||
@tag_container = tag_container
|
||
end
|
||
|
||
def <<(tags, options = {})
|
||
@tag_container.tag(tags, options.merge(:clear => false))
|
||
end
|
||
|
||
alias_method :concat, :<<
|
||
end
|
||
|
||
end
|
||
end
|
||
end
|
||
|
||
ActiveRecord::Base.class_eval do
|
||
include ActiveRecord::Acts::Taggable
|
||
end
|