diff options
Diffstat (limited to 'app/models/concerns/relative_positioning.rb')
| -rw-r--r-- | app/models/concerns/relative_positioning.rb | 52 |
1 files changed, 36 insertions, 16 deletions
diff --git a/app/models/concerns/relative_positioning.rb b/app/models/concerns/relative_positioning.rb index e4fe46d722a..9cd7b8d6258 100644 --- a/app/models/concerns/relative_positioning.rb +++ b/app/models/concerns/relative_positioning.rb @@ -1,5 +1,26 @@ # frozen_string_literal: true +# This module makes it possible to handle items as a list, where the order of items can be easily altered +# Requirements: +# +# - Only works for ActiveRecord models +# - relative_position integer field must present on the model +# - This module uses GROUP BY: the model should have a parent relation, example: project -> issues, project is the parent relation (issues table has a parent_id column) +# +# Setup like this in the body of your class: +# +# include RelativePositioning +# +# # base query used for the position calculation +# def self.relative_positioning_query_base(issue) +# where(deleted: false) +# end +# +# # column that should be used in GROUP BY +# def self.relative_positioning_parent_column +# :project_id +# end +# module RelativePositioning extend ActiveSupport::Concern @@ -93,7 +114,7 @@ module RelativePositioning return move_after(before) unless after return move_before(after) unless before - # If there is no place to insert an issue we need to create one by moving the before issue closer + # If there is no place to insert an item we need to create one by moving the before item closer # to its predecessor. This process will recursively move all the predecessors until we have a place if (after.relative_position - before.relative_position) < 2 before.move_before @@ -108,11 +129,11 @@ module RelativePositioning pos_after = before.next_relative_position if before.shift_after? - issue_to_move = self.class.in_parents(parent_ids).find_by!(relative_position: pos_after) - issue_to_move.move_after - @positionable_neighbours = [issue_to_move] # rubocop:disable Gitlab/ModuleWithInstanceVariables + item_to_move = self.class.relative_positioning_query_base(self).find_by!(relative_position: pos_after) + item_to_move.move_after + @positionable_neighbours = [item_to_move] # rubocop:disable Gitlab/ModuleWithInstanceVariables - pos_after = issue_to_move.relative_position + pos_after = item_to_move.relative_position end self.relative_position = self.class.position_between(pos_before, pos_after) @@ -123,11 +144,11 @@ module RelativePositioning pos_before = after.prev_relative_position if after.shift_before? - issue_to_move = self.class.in_parents(parent_ids).find_by!(relative_position: pos_before) - issue_to_move.move_before - @positionable_neighbours = [issue_to_move] # rubocop:disable Gitlab/ModuleWithInstanceVariables + item_to_move = self.class.relative_positioning_query_base(self).find_by!(relative_position: pos_before) + item_to_move.move_before + @positionable_neighbours = [item_to_move] # rubocop:disable Gitlab/ModuleWithInstanceVariables - pos_before = issue_to_move.relative_position + pos_before = item_to_move.relative_position end self.relative_position = self.class.position_between(pos_before, pos_after) @@ -141,13 +162,13 @@ module RelativePositioning self.relative_position = self.class.position_between(min_relative_position || START_POSITION, MIN_POSITION) end - # Indicates if there is an issue that should be shifted to free the place + # Indicates if there is an item that should be shifted to free the place def shift_after? next_pos = next_relative_position next_pos && (next_pos - relative_position) == 1 end - # Indicates if there is an issue that should be shifted to free the place + # Indicates if there is an item that should be shifted to free the place def shift_before? prev_pos = prev_relative_position prev_pos && (relative_position - prev_pos) == 1 @@ -159,7 +180,7 @@ module RelativePositioning def save_positionable_neighbours return unless @positionable_neighbours - status = @positionable_neighbours.all? { |issue| issue.save(touch: false) } + status = @positionable_neighbours.all? { |item| item.save(touch: false) } @positionable_neighbours = nil status @@ -170,16 +191,15 @@ module RelativePositioning # When calculating across projects, this is much more efficient than # MAX(relative_position) without the GROUP BY, due to index usage: # https://gitlab.com/gitlab-org/gitlab-ce/issues/54276#note_119340977 - relation = self.class - .in_parents(parent_ids) + relation = self.class.relative_positioning_query_base(self) .order(Gitlab::Database.nulls_last_order('position', 'DESC')) + .group(self.class.relative_positioning_parent_column) .limit(1) - .group(self.class.parent_column) relation = yield relation if block_given? relation - .pluck(self.class.parent_column, Arel.sql("#{calculation}(relative_position) AS position")) + .pluck(self.class.relative_positioning_parent_column, Arel.sql("#{calculation}(relative_position) AS position")) .first&. last end |