60 lines
2.1 KiB
Ruby
60 lines
2.1 KiB
Ruby
# frozen_string_literal: true
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# This module is providing helpers for updating `ProjectStatistics` with `after_save` and `before_destroy` hooks.
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#
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# It deals with `ProjectStatistics.increment_statistic` making sure not to update statistics on a cascade delete from the
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# project, and keeping track of value deltas on each save. It updates the DB only when a change is needed.
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#
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# How to use
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# - Invoke `update_project_statistics stat: :a_project_statistics_column, attribute: :an_attr_to_track` in a model class body.
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#
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# Expectation
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# - `attribute` must be an ActiveRecord attribute
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# - The model must implement `project` and `project_id`. i.e. direct Project relationship or delegation
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module UpdateProjectStatistics
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extend ActiveSupport::Concern
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class_methods do
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attr_reader :statistic_name, :statistic_attribute
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# Configure the model to update +stat+ on ProjectStatistics when +attribute+ changes
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#
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# +stat+:: a column of ProjectStatistics to update
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# +attribute+:: an attribute of the current model, default to +:size+
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def update_project_statistics(stat:, attribute: :size)
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@statistic_name = stat
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@statistic_attribute = attribute
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after_save(:update_project_statistics_after_save, if: :update_project_statistics_attribute_changed?)
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after_destroy(:update_project_statistics_after_destroy, unless: :project_destroyed?)
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end
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private :update_project_statistics
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end
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included do
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private
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def project_destroyed?
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project.pending_delete?
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end
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def update_project_statistics_attribute_changed?
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saved_change_to_attribute?(self.class.statistic_attribute)
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end
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def update_project_statistics_after_save
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attr = self.class.statistic_attribute
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delta = read_attribute(attr).to_i - attribute_before_last_save(attr).to_i
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update_project_statistics(delta)
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end
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def update_project_statistics_after_destroy
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update_project_statistics(-read_attribute(self.class.statistic_attribute).to_i)
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end
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def update_project_statistics(delta)
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ProjectStatistics.increment_statistic(project_id, self.class.statistic_name, delta)
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end
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end
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end
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