Module: CollectiveIdea::Acts::NestedSet::Base::ClassMethods

Defined in:
lib/nested_set/base.rb

Instance Method Summary collapse

Instance Method Details

#after_move(*args, &block) ⇒ Object 



271
272
273
 
# File 'lib/nested_set/base.rb', line 271

def after_move(*args, &block)
  set_callback :move, :after, *args, &block
end

#all_roots_valid? ⇒ Boolean

Wrapper for each_root_valid? that can deal with scope.

Returns:

  • (Boolean) 


190
191
192
193
194
195
196
197
198
 
# File 'lib/nested_set/base.rb', line 190

def all_roots_valid?
  if acts_as_nested_set_options[:scope]
    roots.group_by{|record| scope_column_names.collect{|col| record.send(col.to_sym)}}.all? do |scope, grouped_roots|
      each_root_valid?(grouped_roots)
    end
  else
    each_root_valid?(roots)
  end
end

#arrange ⇒ Object

Returns arranged nodes hash. I.e. you have this tree:

1
  2
  3
    4
      5
    6
7

Hash will looks like:

{1 => {2 => {}, 3 => {4 => {5 => {}}, 6 => {}}}, 7 => {}}

Usage:

Categories.arrange
Categories.find(42).children.arrange
Categories.find(42).descendants.arrange
Categories.find(42).self_and_descendants.arrange

This arranged hash can be rendered with recursive render_tree helper



143
144
145
146
147
148
149
150
151
152
153
154
155
 
# File 'lib/nested_set/base.rb', line 143

def arrange
  arranged = ActiveSupport::OrderedHash.new
  insertion_points = [arranged]
  depth = 0
  order("#{quoted_table_name}.#{quoted_left_column_name}").each_with_level do |node, level|
    next if level > depth && insertion_points.last.keys.last && node.parent_id != insertion_points.last.keys.last.id
    insertion_points.push insertion_points.last.values.last if level > depth
    (depth - level).times { insertion_points.pop } if level < depth
    insertion_points.last.merge! node => ActiveSupport::OrderedHash.new
    depth = level
  end
  arranged
end

#before_move(*args, &block) ⇒ Object 



267
268
269
 
# File 'lib/nested_set/base.rb', line 267

def before_move(*args, &block)
  set_callback :move, :before, *args, &block
end

#each_root_valid?(roots_to_validate) ⇒ Boolean

Returns:

  • (Boolean) 


200
201
202
203
204
205
206
207
208
 
# File 'lib/nested_set/base.rb', line 200

def each_root_valid?(roots_to_validate)
  left = right = 0
  roots_to_validate.all? do |root|
    (root.left > left && root.right > right).tap do
      left = root.left
      right = root.right
    end
  end
end

#each_with_level(objects = nil) ⇒ Object

Iterates over tree elements and determines the current level in the tree. Only accepts default ordering, odering by an other column than lft does not work. This method is much more efficent than calling level because it doesn’t require any additional database queries.

Example:

Category.each_with_level(Category.root.self_and_descendants) do |o, level|



246
247
248
249
250
251
252
253
254
255
256
257
 
# File 'lib/nested_set/base.rb', line 246

def each_with_level(objects = nil)
  levels = []
  (objects || scoped).each do |i|
    if level = levels.index(i.parent_id)
      levels.slice!((level + 1)..-1)
    else
      levels << i.parent_id
      level = levels.size - 1
    end
    yield(i, level)
  end
end

#left_and_rights_valid? ⇒ Boolean

Returns:

  • (Boolean) 


161
162
163
164
165
166
167
168
169
170
171
172
173
 
# File 'lib/nested_set/base.rb', line 161

def left_and_rights_valid?
  joins("LEFT OUTER JOIN #{quoted_table_name} AS parent ON " +
      "#{quoted_table_name}.#{quoted_parent_column_name} = parent.#{primary_key}").
  where(
      "#{quoted_table_name}.#{quoted_left_column_name} IS NULL OR " +
      "#{quoted_table_name}.#{quoted_right_column_name} IS NULL OR " +
      "#{quoted_table_name}.#{quoted_left_column_name} >= " +
        "#{quoted_table_name}.#{quoted_right_column_name} OR " +
      "(#{quoted_table_name}.#{quoted_parent_column_name} IS NOT NULL AND " +
        "(#{quoted_table_name}.#{quoted_left_column_name} <= parent.#{quoted_left_column_name} OR " +
        "#{quoted_table_name}.#{quoted_right_column_name} >= parent.#{quoted_right_column_name}))"
  ).exists? == false
end

#map_with_level(objects = nil) ⇒ Object 



259
260
261
262
263
264
265
 
# File 'lib/nested_set/base.rb', line 259

def map_with_level(objects = nil)
  result = []
  each_with_level objects do |object, level|
    result << yield(object, level)
  end
  result
end

#no_duplicates_for_columns? ⇒ Boolean

Returns:

  • (Boolean) 


175
176
177
178
179
180
181
182
183
184
185
186
187
 
# File 'lib/nested_set/base.rb', line 175

def no_duplicates_for_columns?
  scope_string = Array(acts_as_nested_set_options[:scope]).map do |c|
    connection.quote_column_name(c)
  end.push(nil).join(", ")
  [quoted_left_column_name, quoted_right_column_name].all? do |column|
    # No duplicates
    unscoped.first(
      :select => "#{scope_string}#{column}, COUNT(#{column})",
      :group => "#{scope_string}#{column}",
      :having => "COUNT(#{column}) > 1"
    ).nil?
  end
end

#rebuild! ⇒ Object

Rebuilds the left & rights if unset or invalid. Also very useful for converting from acts_as_tree.



211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
 
# File 'lib/nested_set/base.rb', line 211

def rebuild!
  # Don't rebuild a valid tree.
  return true if valid?

  indices = {}

  set_left_and_rights = lambda do |node|
    node_scope = scope_for_rebuild(node)
    # set left
    node[left_column_name] = indices[node_scope] += 1
    # find
    nodes_for_rebuild(node, node_scope).each{ |n| set_left_and_rights.call(n) }
    # set right
    node[right_column_name] = indices[node_scope] += 1
    node.save(:validate => false)
  end

  # Find root node(s)
  root_nodes_for_rebuild.each do |root_node|
    node_scope = scope_for_rebuild(root_node)
    # setup index for this scope
    indices[node_scope] ||= 0
    set_left_and_rights.call(root_node)
  end
end

#root ⇒ Object

Returns the first root



116
117
118
 
# File 'lib/nested_set/base.rb', line 116

def root
  roots.first
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


157
158
159
 
# File 'lib/nested_set/base.rb', line 157

def valid?
  left_and_rights_valid? && no_duplicates_for_columns? && all_roots_valid?
end