Add Background processing and UI Forms for CSV exports (#198)

This change adds the scaffolding to let an administrator:
1. Select 1-3 objects for a CSV export
2. Submit an Export job
3. Run the job in the background
4. View the results
5. Download the exported file

We expect to provide a different UX for selecting items for export,
so the submission form is very bare-bones but functional.

The status (show) page for exports need additional design but provides
enough functionality to download the exported CSV for testing.

app/controllers/exports_controller.rb

@@ -8,12 +8,28 @@ def index
   end
 
   def new
-    super
-    redirect_to new_export_path
+    @job = Export.new
   end
 
   def show
     super
     add_breadcrumb "##{@job.id} - #{I18n.t('tenejo.admin.sidebar.exports')}", @job
   end
+
+  def create
+    @job = Export.new(job_params.merge({ user: current_user, status: :submitted }))
+    respond_to do |format|
+      if @job.save
+        BatchExportJob.perform_later(@job)
+        format.html { redirect_to @job }
+        format.json { render :show, status: :created, location: @job }
+      end
+    end
+  end
+
+  private
+
+  def job_params
+    params.require(:export).permit(identifiers: [])
+  end
 end

app/jobs/batch_export_job.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+class BatchExportJob < ApplicationJob
+  queue_as :default
+
+  def perform(export_job)
+    # probably not optimal, but enough until we get
+    # import hammered out
+    Tenejo::CsvExporter.new(export_job).run
+  end
+end

app/lib/tenejo/csv_exporter.rb

@@ -4,22 +4,34 @@
 
 module Tenejo
   class CsvExporter
-    EXPORT_HEADERS = ([:primary_identifier, :error, :class, :title] + Tenejo::CsvImporter.collection_attributes_to_copy.keys + Tenejo::CsvImporter.work_attributes_to_copy.keys).uniq
+    EXCLUDE_FROM_EXPORT = [:date_modified, :identifier, :label, :arkivo_checksum, :state].freeze
+    HEADER_ROW = (([:primary_identifier, :error, :class, :title] \
+                  + Tenejo::CsvImporter.collection_attributes_to_copy.keys \
+                  + Tenejo::CsvImporter.work_attributes_to_copy.keys).uniq \
+                  - EXCLUDE_FROM_EXPORT).freeze
 
     def initialize(export_job)
       @export = export_job
     end
 
     def run
+      @export.status = :in_progress
+      @export.save
       output = CSV.generate(encoding: 'UTF-8', write_headers: true) do |csv|
-        csv << EXPORT_HEADERS # Header row
+        csv << HEADER_ROW
         csv << CSV::Row.new([:primary_identifier, :error], ["missing", "No identifiers provided"]) if @export.identifiers.empty?
         @export.identifiers.each do |id|
           csv << serialize(id)
         end
       end
 
+      # TODO: remove this after refactoring Tenejo metadata to rename primary_identifier and identifer
+      output.gsub!('primary_identifier,error,class,', 'identifier,error,object type,')
+
       @export.manifest.attach(io: StringIO.new(output), filename: export_name, content_type: 'text/csv')
+      @export.status = :complete
+      @export.completed_at = Time.current
+      @export.save
     end
 
     private
@@ -37,8 +49,8 @@ def export_name
     def serialize(id)
       obj = ActiveFedora::Base.where(primary_identifier_ssi: id).last
       return CSV::Row.new([:primary_identifier, :error], [id, "No match for identifier"]) unless obj
-      values = EXPORT_HEADERS.map { |attr| pack_field(obj.try(attr)) }
-      CSV::Row.new(EXPORT_HEADERS, values)
+      values = HEADER_ROW.map { |attr| pack_field(obj.try(attr)) }
+      CSV::Row.new(HEADER_ROW, values)
     end
 
     # Handle multi-value fields and normalize empty fields regardless of underlying class

app/views/exports/new.html.erb

@@ -0,0 +1,32 @@
+<h1>New <%= @job.class %></h1>
+
+<%= form_with(model: @job, local: true) do |form| %>
+  <% if @job.errors.any? %>
+    <div id="error_explanation">
+      <h2><%= pluralize(@job.errors.count, "error") %> prohibited this job from being saved:</h2>
+
+      <ul>
+        <% @job.errors.full_messages.each do |message| %>
+          <li><%= message %></li>
+        <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div class="field">
+    <%= form.label :identifiers %>
+    <%= form.text_field :identifiers, id: 'export_identifiers_0', value: @job.identifiers[0], multiple: true %>
+  </div>
+  <div class="field">
+    <%= form.label :identifiers %>
+    <%= form.text_field :identifiers, id: 'export_identifiers_1', value: @job.identifiers[1], multiple: true %>
+  </div>
+  <div class="field">
+    <%= form.label :identifiers %>
+    <%= form.text_field :identifiers, id: 'export_identifiers_2', value: @job.identifiers[2], multiple: true %>
+  </div>
+  <br/>
+  <div class="actions">
+    <%= form.submit 'Submit', type: 'submit' %>
+  </div>
+<% end %>

spec/lib/tenejo/csv_exporter_spec.rb

@@ -35,7 +35,7 @@
       export.save
       described_class.new(export).run
       rows = CSV.parse(export.manifest.download, headers: true)
-      expect(rows.first['primary_identifier']).to eq 'invalid_id'
+      expect(rows.first['identifier']).to eq 'invalid_id'
       expect(rows.first['error']).to eq 'No match for identifier'
     end
 
@@ -48,16 +48,16 @@
       rows = CSV.parse(export.manifest.download, headers: true)
 
       # Collection COL001
-      expect(rows[0]['primary_identifier']).to eq 'COL001'
+      expect(rows[0]['identifier']).to eq 'COL001'
       expect(rows[0]['error']).to be_nil
       expect(rows[0]['title']).to include 'Test collection'
-      expect(rows[0]['class']).to eq "Collection"
+      expect(rows[0]['object type']).to eq "Collection"
 
       # Work WRK001
-      expect(rows[1]['primary_identifier']).to eq 'WRK001'
+      expect(rows[1]['identifier']).to eq 'WRK001'
       expect(rows[1]['error']).to be_nil
       expect(rows[1]['title']).to include 'Test work'
-      expect(rows[1]['class']).to eq "Work"
+      expect(rows[1]['object type']).to eq "Work"
     end
   end
 

spec/requests/export_request_spec.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+RSpec.describe "/exports", type: :request do
+  let(:admin) { FactoryBot.create(:user, :admin) }
+  let(:export) { Export.new(user: admin) }
+
+  before do
+    sign_in admin
+  end
+
+  describe "GET /index" do
+    it "redirects to /jobs/index" do
+      get exports_path
+      expect(response).to redirect_to jobs_path
+    end
+  end
+
+  describe "GET /new" do
+    it "renders a successful response" do
+      get new_export_path
+      expect(response).to render_template('exports/new')
+    end
+  end
+
+  describe "GET /show" do
+    it "displays info for an export job" do
+      export.save!
+      get export_path export
+      expect(response).to render_template('exports/show')
+    end
+  end
+
+  describe "POST /create" do
+    it "creates a new export job" do
+      expect {
+        post exports_path, params: { export: { identifiers: [] } }
+      }.to change(Export, :count).by(1)
+    end
+
+    it "queues a new background job" do
+      ActiveJob::Base.queue_adapter = :test
+      expect {
+        post exports_path, params: { export: { identifiers: [] } }
+      } .to enqueue_job(BatchExportJob).with(Job.last).on_queue(:default)
+    end
+
+    it "redirects to the submitted export show view" do
+      post exports_path, params: { export: { identifiers: [] } }
+      expect(response).to redirect_to Export.last
+    end
+  end
+end

spec/routing/exports_routing_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+require "rails_helper"
+
+RSpec.describe ExportsController, type: :routing do
+  describe "routing" do
+    it "routes to #index" do
+      expect(get: "/exports").to route_to("exports#index")
+    end
+
+    it "routes to #new" do
+      expect(get: "/exports/new").to route_to("exports#new")
+    end
+
+    it "routes to #show" do
+      expect(get: "/exports/1").to route_to("exports#show", id: "1")
+    end
+
+    it "routes to #create" do
+      expect(post: "/exports").to route_to("exports#create")
+    end
+
+    # Preflight jobs are not editable after creation
+    context 'invalid routes' do
+      it "does not route to #edit" do
+        expect(get: "/exports/1/edit").not_to be_routable
+      end
+
+      it "does not route to #update via PUT" do
+        expect(put: "/exports/1").not_to be_routable
+      end
+
+      it "does not route to #update via PATCH" do
+        expect(patch: "/exports/1").not_to be_routable
+      end
+
+      it "does not route to #destroy" do
+        expect(delete: "/exports/1").not_to be_routable
+      end
+    end
+  end
+end