Improve experiment preview image generation [SCI-3177]

app/controllers/canvas_controller.rb

@@ -186,7 +186,7 @@ class CanvasController < ApplicationController
     end
 
     # Create workflow image
-    @experiment.delay.generate_workflow_img
+    @experiment.generate_workflow_img
 
     flash[:success] = t('experiments.canvas.update.success_flash')
     redirect_to canvas_experiment_path(@experiment)

app/controllers/experiments_controller.rb

@@ -237,10 +237,14 @@ class ExperimentsController < ApplicationController
   end
 
   def updated_img
+    if @experiment.workflowimg.present? && !@experiment.workflowimg.exists?
+      @experiment.workflowimg = nil
+      @experiment.save
+      @experiment.generate_workflow_img
+    end
     respond_to do |format|
       format.json do
-        if @experiment.workflowimg_updated_at.to_i >=
-           params[:timestamp].to_time.to_i
+        if @experiment.workflowimg.present?
           render json: {}, status: 200
         else
           render json: {}, status: 404

app/models/experiment.rb

@@ -49,8 +49,6 @@ class Experiment < ApplicationRecord
     experiment.validates :archived_on, presence: true
   end
 
-  after_touch { update_column(:workflowimg_updated_at, updated_at) }
-
   scope :is_archived, ->(is_archived) { where("archived = ?", is_archived) }
 
   def self.search(
@@ -222,7 +220,11 @@ class Experiment < ApplicationRecord
   end
 
   def generate_workflow_img
-    Experiments::GenerateWorkflowImageService.call(experiment_id: id)
+    if workflowimg.present?
+      self.workflowimg = nil
+      save
+    end
+    Experiments::GenerateWorkflowImageService.delay.call(experiment_id: id)
   end
 
   # Get projects where user is either owner or user in the same team
@@ -423,7 +425,7 @@ class Experiment < ApplicationRecord
   # to other experiment
   def generate_workflow_img_for_moved_modules(to_move)
     Experiment.where(id: to_move.values.uniq).each do |exp|
-      exp.delay.generate_workflow_img
+      exp.generate_workflow_img
     end
   end
 

app/models/my_module.rb

@@ -184,7 +184,7 @@ class MyModule < ApplicationRecord
         raise ActiveRecord::Rollback
       end
     end
-    experiment.delay.generate_workflow_img
+    experiment.generate_workflow_img
     restored
   end
 

app/services/experiments/copy_experiment_as_template_service.rb

@@ -43,7 +43,7 @@ module Experiments
       @errors.merge!(@c_exp.errors.to_hash) unless @c_exp.valid?
 
       @c_exp = nil unless succeed?
-      @c_exp.delay.generate_workflow_img if succeed?
+      @c_exp.generate_workflow_img if succeed?
       track_activity if succeed?
 
       self

app/services/experiments/generate_workflow_image_service.rb

@@ -80,8 +80,6 @@ module Experiments
       file.close
       @exp.save
       @exp.touch(:workflowimg_updated_at)
-    rescue StandardError => ex
-      logger.error ex.message
     end
   end
 end

app/services/team_importer.rb

@@ -565,7 +565,7 @@ class TeamImporter
       my_module_group.save!
       @my_module_group_mappings[orig_module_group_id] = my_module_group.id
     end
-    experiment.delay.generate_workflow_img
+    experiment.generate_workflow_img
     create_my_modules(experiment_json['my_modules'], experiment, user_id)
     experiment
   end

app/utilities/first_time_data_generator.rb

@@ -1398,7 +1398,7 @@ module FirstTimeDataGenerator
     )
 
     # create thumbnail
-    experiment.delay.generate_workflow_img
+    experiment.generate_workflow_img
   end
 
   # Used for delayed jobs