Module: Tagtical::Taggable::Core::ClassMethods

Defined in:
lib/tagtical/taggable/core.rb

Instance Method Summary collapse

Instance Method Details

#acts_as_taggable(*args) ⇒ Object 



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# File 'lib/tagtical/taggable/core.rb', line 80

def acts_as_taggable(*args)
  super(*args)
  initialize_tagtical_core
end

#define_has_tag_scope(tag_type) ⇒ Object

Defines has and has_no scopes at the class level.



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# File 'lib/tagtical/taggable/core.rb', line 91

def define_has_tag_scope(tag_type)
  tag_table, tagging_table = Tagtical::Tag.table_name, Tagtical::Tagging.table_name

  scope "has_no_#{tag_type.has_many_name}", lambda { |*args|
    args << args.extract_options!.update(:sql => :append)
    select("#{table_name}.*").
      joins("LEFT OUTER JOIN #{tagging_table} ON ( #{tagging_table}.taggable_id = #{table_name}.id )").
      joins(%{LEFT OUTER JOIN #{tag_table} ON ( #{tag_table}.id = #{tagging_table}.tag_id #{tag_type.finder_type_condition(*args)} )}).
      where("#{tag_table}.id IS NULL").
      group("#{table_name}.id")
    }
end

#define_tag_scope(tag_type) ⇒ Object

If the tag_type is base? (type==“tag”), then we add additional functionality to the AR has_many :tags.

taggable_model.tags(:scope => :children)
taggable_model.tags <-- still works like normal has_many
taggable_model.tags(true, :scope => :current) <-- reloads the tags association and appends scope for only current type.



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# File 'lib/tagtical/taggable/core.rb', line 110

def define_tag_scope(tag_type)
  if tag_type.has_many_name==:tags
    define_method("tags_with_finder_type_options") do |*args|
      bool = args.shift if [true, false].include?(args.first)
      tags = tags_without_finder_type_options(bool)
      args.empty? ? tags : tags_with_type_scoping(tag_type, *args)
    end
    alias_method_chain :tags, :finder_type_options
  else # handle the Tagtical::Tag subclasses
    define_method(tag_type.scope_name) do |*args|
      if tags.loaded?
        cache = instance_variable_get(tag_type.scope_ivar) || instance_variable_set(tag_type.scope_ivar, {})
        tag_type_classes = expand_tag_types(tag_type, *args).map(&:klass)
        cache[tag_type_classes] ||= tags_with_type_scoping(tag_type, *args).tap do |scope|
          scope.instance_variable_set(:@loaded, true)
          scope.instance_variable_set(:@records, tags.select { |t| tag_type_classes.include?(t.class) })
        end
      else
        tags_with_type_scoping(tag_type, *args)
      end
    end
  end
end

#eager_load_tag_classes ⇒ Object

Ensure that the tag classes are loaded.



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# File 'lib/tagtical/taggable/core.rb', line 86

def eager_load_tag_classes
  tag_types.each(&:klass)
end

#find_tag_type!(input, options = {}) ⇒ Object 



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# File 'lib/tagtical/taggable/core.rb', line 139

def find_tag_type!(input, options={})
  (@tag_type ||= {})[input] ||= tag_types.find { |t| t.match?(input) } || raise("Cannot find tag type:'#{input}' in #{tag_types.inspect}")
end

#grouped_column_names_for(object) ⇒ Object

all column names are necessary for PostgreSQL group clause



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# File 'lib/tagtical/taggable/core.rb', line 135

def grouped_column_names_for(object)
  object.column_names.map { |column| "#{object.table_name}.#{column}" }.join(", ")
end

#initialize_tagtical_core ⇒ Object 



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# File 'lib/tagtical/taggable/core.rb', line 39

def initialize_tagtical_core
  has_many :taggings, :as => :taggable, :dependent => :destroy, :include => :tag, :class_name => "Tagtical::Tagging"
  has_many :tags, :through => :taggings, :source => :tag, :class_name => "Tagtical::Tag",
           :select => "#{Tagtical::Tag.table_name}.*, #{Tagtical::Tagging.table_name}.relevance as relevance, #{Tagtical::Tagging.table_name}.tagger_id as tagger_id" # include the relevance on the tags

  tag_types.each do |tag_type| # has_many :tags gets created here

    # Aryk: Instead of defined multiple associations for the different types of tags, I decided
    # to define the main associations (tags and taggings) and use AR scope's to build off of them.
    # This keeps your reflections cleaner.

    # In the case of the base tag type, it will just use the :tags association defined above.
    Tagtical::Tag.define_scope_for_type(tag_type)

    define_tag_scope(tag_type)
    
    define_has_tag_scope(tag_type)

    class_eval <<-RUBY, __FILE__, __LINE__ + 1
      def self.with_#{tag_type.pluralize}(*tags)
        options = tags.extract_options!
        tagged_with(tags.flatten, options.merge(:on => :#{tag_type}))
      end

      def #{tag_type}_list(*args)
        tag_list_on('#{tag_type}', *args)
      end

      def #{tag_type}_list=(new_tags, *args)
        set_tag_list_on('#{tag_type}', new_tags, *args)
      end
      alias set_#{tag_type}_list #{tag_type}_list=

      def all_#{tag_type.pluralize}_list(*args)
        all_tags_list_on('#{tag_type}', *args)
      end
    RUBY

  end
end

#is_taggable? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tagtical/taggable/core.rb', line 237

def is_taggable?
  true
end

#tagged_with(tags, options = {}) ⇒ Object

Return a scope of objects that are tagged with the specified tags.

Example:

User.tagged_with("awesome", "cool")                     # Users that are tagged with awesome and cool
User.tagged_with("awesome", "cool", :exclude => true)   # Users that are not tagged with awesome or cool
User.tagged_with("awesome", "cool", :any => true)       # Users that are tagged with awesome or cool
User.tagged_with("awesome", "cool", :match_all => true) # Users that are tagged with just awesome and cool
User.tagged_with("awesome", "cool", :on => :skills)     # Users that are tagged with just awesome and cool on skills

Parameters:

  • tags —

    The tags that we want to query for

  • options (Hash) (defaults to: {}) —

    A hash of options to alter you query:

    • :exclude - if set to true, return objects that are NOT tagged with the specified tags

    • :any - if set to true, return objects that are tagged with ANY of the specified tags

    • :match_all - if set to true, return objects that are ONLY tagged with the specified tags



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# File 'lib/tagtical/taggable/core.rb', line 158

def tagged_with(tags, options = {})
  tag_list = Tagtical::TagList.from(tags)
  return scoped(:conditions => "1 = 0") if tag_list.empty? && !options[:exclude]

  joins = []
  conditions = []

  tag_type = find_tag_type!(options.delete(:on) || Tagtical::Tag::Type::BASE)
  finder_type_condition_options = options.extract!(:scope)

  tag_table, tagging_table = Tagtical::Tag.table_name, Tagtical::Tagging.table_name

  if options.delete(:exclude)
    conditions << "#{table_name}.#{primary_key} NOT IN (" +
      "SELECT #{tagging_table}.taggable_id " +
      "FROM #{tagging_table} " +
      "JOIN #{tag_table} ON #{tagging_table}.tag_id = #{tag_table}.id AND #{tag_list.to_sql_conditions(:operator => "LIKE")} " +
      "WHERE #{tagging_table}.taggable_type = #{quote_value(base_class.name)})"

  elsif options.delete(:any)
    conditions << tag_list.to_sql_conditions(:operator => "LIKE")

    tagging_join  = " JOIN #{tagging_table}" +
      "   ON #{tagging_table}.taggable_id = #{table_name}.#{primary_key}" +
      "  AND #{tagging_table}.taggable_type = #{quote_value(base_class.name)}" +
      " JOIN #{tag_table}" +
      "   ON #{tagging_table}.tag_id = #{tag_table}.id"


    if (finder_condition = tag_type.finder_type_condition(finder_type_condition_options.merge(:sql => true))).present?
      conditions << finder_condition
    end

    select_clause = "DISTINCT #{table_name}.*" if tag_type.klass.descends_from_active_record? || !tag_types.one?

    joins << tagging_join

  else
    tags_by_value = tag_type.scoping(finder_type_condition_options).where_any_like(tag_list).group_by(&:value)
    return scoped(:conditions => "1 = 0") unless tags_by_value.length == tag_list.length # allow for chaining

    # Create only one join per tag value.
    tags_by_value.each do |value, tags|
      tags.each do |tag|
        safe_tag = value.gsub(/[^a-zA-Z0-9]/, '')
        prefix   = "#{safe_tag}_#{rand(1024)}"

        taggings_alias = "#{undecorated_table_name}_taggings_#{prefix}"

        tagging_join  = "JOIN #{tagging_table} #{taggings_alias}" +
          "  ON #{taggings_alias}.taggable_id = #{table_name}.#{primary_key}" +
          " AND #{taggings_alias}.taggable_type = #{quote_value(base_class.name)}" +
          " AND #{sanitize_sql("#{taggings_alias}.tag_id" => tags.map(&:id))}"

        joins << tagging_join
      end
    end
  end

  taggings_alias, tags_alias = "#{undecorated_table_name}_taggings_group", "#{undecorated_table_name}_tags_group"

  if options.delete(:match_all)
    joins << "LEFT OUTER JOIN #{tagging_table} #{taggings_alias}" +
      "  ON #{taggings_alias}.taggable_id = #{table_name}.#{primary_key}" +
      " AND #{taggings_alias}.taggable_type = #{quote_value(base_class.name)}"


    group_columns = Tagtical::Tag.using_postgresql? ? grouped_column_names_for(self) : "#{table_name}.#{primary_key}"
    group = "#{group_columns} HAVING COUNT(#{taggings_alias}.taggable_id) = #{tag_list.size}"
  end

  scoped(:select     => select_clause,
         :joins      => joins.join(" "),
         :group      => group,
         :conditions => conditions.join(" AND "),
         :order      => options[:order],
         :readonly   => false)
end