Class: Decidim::Log::DiffChangesetCalculator

Inherits:
Object
  • Object
show all
Defined in:
app/services/decidim/log/diff_changeset_calculator.rb

Overview

This class takes a changeset from a ‘PaperTrail::Version` and a field mapping and cleans the changeset so it can be easily rendered in the log section. It is intended to be used by the `Decidim::Log::BasePresenter` class, which handles most of the work to render a log.

Example:

version = resource.versions.last
fields_mapping = { updated_at: :date, title: :string }
i18n_labels_scope = "activemodel.attributes.my_resource"

DiffChangesetCalculator
  .new(version.changeset, fields_mapping, i18n_labels_scope)
  .changeset

Instance Method Summary collapse

Constructor Details

#initialize(original_changeset, fields_mapping, i18n_labels_scope) ⇒ DiffChangesetCalculator

original_changeset - a ‘changeset` from a PaperTrail::Version instance fields_mapping - a Hash mapping attribute names and a type to render them i18n_labels_scope - a String representing the I18n scope where the attribute

labels can be found



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# File 'app/services/decidim/log/diff_changeset_calculator.rb', line 25

def initialize(original_changeset, fields_mapping, i18n_labels_scope)
  @original_changeset = original_changeset
  @fields_mapping = fields_mapping
  @i18n_labels_scope = i18n_labels_scope
end

Instance Method Details

#changeset ⇒ Object

Calculates the changeset that should be rendered, from the ‘original_changeset` and the `fields_mapping` values.

Returns an Array of Hashes.



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# File 'app/services/decidim/log/diff_changeset_calculator.rb', line 35

def changeset
  original_changeset.inject([]) do |diff, (attribute, values)|
    attribute = attribute.to_sym

    type = :default
    type = fields_mapping[attribute] unless fields_mapping.nil?

    if type.blank? || values[0] == values[1]
      diff
    else
      diff.concat(calculate_changeset(attribute, values, type))
    end
  end.compact
end