Merge pull request #7832 from betagouv/perf_dossier_save

perf(dossier_controller): améliore la performance d'affichage d'un dossier

app/controllers/users/dossiers_controller.rb

@@ -392,7 +392,7 @@ module Users
     end
 
     def dossier_with_champs
-      dossier_scope.with_champs.find(params[:id])
+      DossierPreloader.load_one(dossier)
     end
 
     def should_change_groupe_instructeur?

app/models/dossier_preloader.rb

@@ -11,12 +11,16 @@ class DossierPreloader
     dossiers
   end
 
-  def all
+  def all(pj_template: false)
     dossiers = @dossiers.to_a
-    load_dossiers(dossiers)
+    load_dossiers(dossiers, pj_template:)
     dossiers
   end
 
+  def self.load_one(dossier)
+    DossierPreloader.new([dossier]).all(pj_template: true).first
+  end
+
   private
 
   # returns: { revision_id : { type_de_champ_id : position } }
@@ -30,9 +34,17 @@ class DossierPreloader
       end
   end
 
-  def load_dossiers(dossiers)
+  def load_dossiers(dossiers, pj_template: false)
+    to_include = [piece_justificative_file_attachment: :blob]
+
+    if pj_template
+      to_include << { type_de_champ: { piece_justificative_template_attachment: :blob } }
+    else
+      to_include << :type_de_champ
+    end
+
     all_champs = Champ
-      .includes(:type_de_champ, piece_justificative_file_attachment: :blob)
+      .includes(to_include)
       .where(dossier_id: dossiers)
       .to_a
 
@@ -80,6 +92,10 @@ class DossierPreloader
   def load_champs(parent, name, champs, dossier, children_by_parent)
     champs.each do |champ|
       champ.association(:dossier).target = dossier
+
+      if parent.is_a?(Champ)
+        champ.association(:parent).target = parent
+      end
     end
 
     parent.association(name).target = champs.sort_by do |champ|
@@ -92,7 +108,6 @@ class DossierPreloader
       parent_champ.association(:dossier).target = dossier
 
       load_champs(parent_champ, :champs, champs, dossier, children_by_parent)
-      parent_champ.association(:champs).set_inverse_instance(parent_champ)
     end
   end
 end

spec/models/dossier_preloader_spec.rb

@@ -0,0 +1,37 @@
+describe DossierPreloader do
+  let(:types_de_champ) do
+    [
+      { type: :text },
+      { type: :repetition, children: [{ type: :text }] }
+    ]
+  end
+  let(:procedure) { create(:procedure, types_de_champ_public: types_de_champ) }
+  let(:dossier) { create(:dossier, procedure: procedure) }
+  let(:repetition) { subject.champs.second }
+  let(:first_child) { subject.champs.second.champs.first }
+
+  describe 'all' do
+    subject { DossierPreloader.load_one(dossier) }
+
+    before { subject }
+
+    it do
+      count = 0
+
+      callback = lambda { |*_args| count += 1 }
+      ActiveSupport::Notifications.subscribed(callback, "sql.active_record") do
+        expect(subject.id).to eq(dossier.id)
+        expect(subject.champs.size).to eq(types_de_champ.size)
+        expect(subject.changed?).to be false
+
+        expect(first_child.type).to eq('Champs::TextChamp')
+        expect(repetition.id).not_to eq(first_child.id)
+        expect(subject.champs.first.dossier).to eq(subject)
+        expect(subject.champs.first.type_de_champ.piece_justificative_template.attached?).to eq(false)
+        expect(first_child.parent).to eq(repetition)
+      end
+
+      expect(count).to eq(0)
+    end
+  end
+end