forked from fixin.me/fixin.me
118 lines
4.2 KiB
Ruby
118 lines
4.2 KiB
Ruby
class Quantity < ApplicationRecord
|
|
ATTRIBUTES = [:name, :description, :parent_id]
|
|
|
|
belongs_to :user, optional: true
|
|
belongs_to :parent, optional: true, class_name: "Quantity"
|
|
has_many :subquantities, class_name: "Quantity", inverse_of: :parent,
|
|
dependent: :restrict_with_error
|
|
|
|
validate if: ->{ parent.present? } do
|
|
errors.add(:parent, :user_mismatch) unless user == parent.user
|
|
errors.add(:parent, :self_reference) if self == parent
|
|
end
|
|
validate if: ->{ parent.present? }, on: :update do
|
|
errors.add(:parent, :descendant_reference) if ancestor_of?(parent)
|
|
end
|
|
validates :name, presence: true, uniqueness: {scope: [:user_id, :parent_id]},
|
|
length: {maximum: type_for_attribute(:name).limit}
|
|
validates :description, length: {maximum: type_for_attribute(:description).limit}
|
|
|
|
# Not persisted attribute
|
|
attribute :depth, :integer
|
|
|
|
scope :defaults, ->{ where(user: nil) }
|
|
scope :ordered, ->{
|
|
numbered = Arel::Table.new('numbered')
|
|
Quantity.with(numbered: numbered(:parent_id, :name)).with_recursive(quantities: [
|
|
Arel::SelectManager.new.project(
|
|
numbered[Arel.star],
|
|
numbered.cast(numbered[:child_number], 'BINARY').as('path'),
|
|
Arel::Nodes.build_quoted(0).as('depth')
|
|
).from(numbered).where(numbered[:parent_id].eq(nil)),
|
|
Arel::SelectManager.new.project(
|
|
numbered[Arel.star],
|
|
arel_table[:path].concat(numbered[:child_number]),
|
|
arel_table[:depth] + 1
|
|
).from(numbered).join(arel_table).on(numbered[:parent_id].eq(arel_table[:id]))
|
|
]).select(arel_table[Arel.star]).from(arel_table).order(arel_table[:path])
|
|
}
|
|
|
|
# TODO: extract named functions to custom Arel extension
|
|
# https://gist.github.com/ProGM/c6df08da14708dcc28b5ca325df37ceb#extending-arel
|
|
scope :numbered, ->(parent_column, order_column){
|
|
select(
|
|
arel_table[Arel.star],
|
|
Arel::Nodes::NamedFunction.new(
|
|
'LPAD',
|
|
[
|
|
Arel::Nodes::NamedFunction.new('ROW_NUMBER', [])
|
|
.over(Arel::Nodes::Window.new.partition(parent_column).order(order_column)),
|
|
Arel::SelectManager.new.project(
|
|
Arel::Nodes::NamedFunction.new('LENGTH', [Arel.star.count])
|
|
),
|
|
Arel::Nodes.build_quoted('0')
|
|
],
|
|
).as('child_number')
|
|
)
|
|
}
|
|
|
|
def to_s
|
|
name
|
|
end
|
|
|
|
def movable?
|
|
subquantities.empty?
|
|
end
|
|
|
|
def default?
|
|
parent_id.nil?
|
|
end
|
|
|
|
# Return: self, ancestors and successive record in order of appearance,
|
|
# including :depth attribute. Used for partial view reload.
|
|
def successive
|
|
quantities = Quantity.arel_table
|
|
|
|
Quantity.with(
|
|
quantities: user.quantities.ordered.select(
|
|
Arel::Nodes::NamedFunction.new('LAG', [quantities[:id]]).over.as('lag_id')
|
|
)
|
|
).where(quantities[:lag_id].eq(id)).first
|
|
end
|
|
|
|
# Return: ancestors of (possibly destroyed) self; include depths, also on
|
|
# self (unless destroyed)
|
|
def ancestors
|
|
quantities = Quantity.arel_table
|
|
ancestors = Arel::Table.new('ancestors')
|
|
|
|
# Ancestors are listed bottom up, so it's impossible to know depth at the
|
|
# start. Start with depth = 0 and count downwards, then adjust by the
|
|
# amount needed to set biggest negative depth to 0.
|
|
Quantity.with_recursive(ancestors: [
|
|
user.quantities.select(quantities[Arel.star], Arel::Nodes.build_quoted(0).as('depth'))
|
|
.where(id: parent_id),
|
|
user.quantities.select(quantities[Arel.star], ancestors[:depth] - 1)
|
|
.joins(quantities.create_join(
|
|
ancestors, quantities.create_on(quantities[:id].eq(ancestors[:parent_id]))
|
|
))
|
|
]).select(ancestors[Arel.star]).from(ancestors).to_a.then do |records|
|
|
records.map(&:depth).min&.abs.then do |maxdepth|
|
|
self.depth = (maxdepth || -1) + 1 unless frozen?
|
|
records.each { |r| r.depth += maxdepth }
|
|
end
|
|
end
|
|
end
|
|
|
|
def ancestor_of?(descendant)
|
|
quantities = Quantity.arel_table
|
|
ancestors = Arel::Table.new('ancestors')
|
|
Quantity.with_recursive(ancestors: [
|
|
user.quantities.where(id: descendant.id),
|
|
user.quantities.joins(quantities.create_join(
|
|
ancestors, quantities.create_on(quantities[:id].eq(ancestors[:parent_id]))
|
|
))
|
|
]).from(ancestors).exists?(ancestors: {id: id})
|
|
end
|
|
end
|