Module: HierarchicalDb

Extended by:
ActiveSupport::Concern
Defined in:
lib/hierarchical_db.rb,
lib/hierarchical_db/version.rb,
lib/generators/hierarchical_db_generator.rb

Defined Under Namespace

Modules: ClassMethods, Generators

Constant Summary collapse

VERSION = 
"0.1.0"

Instance Method Summary collapse

Instance Method Details

#all_nodes ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 48

def all_nodes
  self.class.where(lft: (self.lft..self.rgt)).order(:lft)
end

#brothers ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 64

def brothers
  unless self.parent.nil?
    self.class.where("lft > ? and rgt < ? and lvl = ?",self.parent.lft, self.parent.rgt, self.lvl)
  else
    list_by_level 1
  end
end

#childs ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 60

def childs
  descendants.where(:lvl => self.lvl + 1)
end

#descendants ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 52

def descendants
  self.class.where(lft: (self.lft + 1..self.rgt - 1)).order(:lft)
end

#descendants_count ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 56

def descendants_count
  (self.rgt - self.lft - 1)/2
end

#destroy_node ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 117

def destroy_node
  unless self.class.is_sorted?
    return
  end
  childs = self.class.where("lft > ?", self.rgt)
  childs.each do |t|
    t.lft = t.lft - 2
    t.save
  end
  childs = self.class.where("rgt > ?", self.rgt)
  childs.each do |t|
    t.rgt = t.rgt - 2
    t.save
  end
end

#display_subtree ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 133

def display_subtree
  right = []
  self.all_nodes.each do |d|
    if right.length > 0
      while right.last < d.rgt do
        right.pop
      end 
    end
    puts ("  "*right.length) +"#{d.id}-" +d.name
    right << d.rgt
  end
  return ''
end

#insert_node ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 76

def insert_node
  unless self.class.is_sorted?
    return
  end
  father = self.parent
  previous_right = ""
  lvl = ""
  #case it has descendants
  unless father.nil?
    last_brother = father.descendants.where(:rgt => father.descendants.maximum(:rgt))
    #case has brothers
    unless last_brother.empty?
      last_brother = last_brother[0]
      previous_right = last_brother.rgt
      lvl = last_brother.lvl
    #case hasn't brothers
    else
      previous_right = father.rgt - 1
      lvl = father.lvl + 1 
    end
    childs = self.class.where("lft > ?", previous_right)
    childs.each do |t|
      t.lft = t.lft + 2
      t.save
    end
    childs = self.class.where("rgt > ?", previous_right)
    childs.each do |t|
      t.rgt = t.rgt + 2
      t.save
    end
  #case it is root
  else
    last_brother = self.class.where(:rgt => self.class.maximum(:rgt))
    last_brother = last_brother[0]
    previous_right = last_brother.rgt
  end
  self.lft = previous_right + 1
  self.rgt = previous_right + 2
  self.lvl = lvl
end

#list_by_level(lvl) ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 72

def list_by_level lvl
  self.class.where(:lvl => lvl)
end

#path(joined = nil, included = false) ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 147

def path(joined = nil, included = false)
  inc = included ? "=" : ""
  nodes = self.class.where("lft <#{inc} ?", self.lft).where("rgt >#{inc} ?", self.rgt).order(:lft)
  return nodes.map(&:name).join(joined) unless joined.nil?
  return nodes
end

#sort_subtree(left, lvl) ⇒ Object 



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# File 'lib/hierarchical_db.rb', line 38

def sort_subtree left, lvl
  right = left + 1
  self.children.each{|child| right = child.sort_subtree(right, lvl + 1) }
  self.lft = left
  self.rgt = right
  self.lvl = lvl
  self.save
  return right + 1
end