Add Metadata to Views, Presenter, and Solr

Goals:

• Add the field to the show view
  • Add a show feature
  • Add the new metadata field to your show feature
  • Make a custom presenter for our Work class
• Add a field to views and solr
  • Add your field to the solr index
  • Add a field to solr document
  • Add a field to the view partial
• Pair exercise

Add the field to the show view

Add a show feature

In part one of this tutorial, we started by writing a feature spec for making a new Work. For part two, we're going to start by writing a feature spec for displaying a Work.

1. Copy this show_work_spec.rb file to spec/features
2. Run your test suite (rails ci or rspec spec). Everything should pass.

Add the new metadata field to your show feature

1. Add your new metadata field to the show spec you just created. You'll need to add it in three places:
   1. As a let statement, where you define the value: let(:year) { ['2010'] }
   2. In the Work.new block
   3. In the expectations See this diff on github for what it should look like when you're done.
2. Run your test suite again (rails ci or rspec spec if you have left your test solr and fedora running). It should fail with the message Failure/Error: expect(page).to have_content work.year.first.

This tells us that our test setup ran successfully (a Work was created with a year field) but the show page doesn't display that field yet.

Modify the presenter for our Work class

Recall that Rails uses an "MVC" or "model-view-controller" pattern. In addition to models, views, and controllers, we also have presenters, sometimes also referred to as a "Decorator" or "View-Model." The presenter is responsible for translating values from the model to a presentable form.

Example:

class BookPresenter
  def initialize(book)
    @book = book
  end

  delegate :title, :creator, to: :@book

  def glitter_title
    '★' + @book.title + '☆'
  end
end

Customize our work-specific presenter

As always, we want to write our test first.

1. Hyrax generated app/presenters/hyrax/work_presenter.rb and spec/presenters/hyrax/work_presenter_spec.rb for you when you created your Work work type. Open these files and take a look.
2. Edit spec/presenters/hyrax/work_presenter_spec.rb. It is only a stubbed spec right now. Replace it with the work_presenter_spec.rb file on github. Note, our year field has already been added to this file.
3. Run your test suite (rails ci). It will fail with the message Failure/Error: it { is_expected.to delegate_method(:year).to(:solr_document) }
4. Add this line to your work_presenter.rb file:

  delegate :year, to: :solr_document

5. Run your test suite again, and notice that our work_presenter_spec now passes. (Your show feature spec will still fail, because year is not yet appearing on our show view.)

For discussion: What does it mean to say that the method has been delegated to solr_document?

Use our custom presenter

In order to use our custom presenter, our Work class has to know about it. Normally, you would have to manually add the custom presenter to the relevant controller, in this case app/controllers/hyrax/works_controller.rb. However, Hyrax did this for you when you ran the work type generator. Open the app/controllers/hyrax/works_controller.rb file and note that it is configured to use Hyrax::WorkPresenter.

  self.show_presenter = Hyrax::WorkPresenter

Add a field to view partial and solr

Add your field to the solr index

1. Edit app/models/work.rb and add instructions for how the year field should be indexed:

  property :year, predicate: "http://www.europeana.eu/schemas/edm/year" do |index|
    index.as :stored_searchable
  end

Add the field to solr_document

1. Edit app/models/solr_document.rb and add this method:

  def year
    self[Solrizer.solr_name('year')]
  end

Add the field to the view partial

1. Copy Hyrax's app/views/hyrax/base/_attribute_rows.html.erb to the same directory structure in your app
2. Edit your newly created local copy of _attribute_rows.html.erb to include your metadata field:

  <%= presenter.attribute_to_html(:year) %>

3. Run your test suite again (rails ci) and your feature test should now pass

Note: You can see all the changes made during this exercise on the github repo.

Pair exercise

We added one metadata field here: year. Choose either extent or references and add a second metadata field. Or, define your own metadata field, as long as you pick something that can be a simple string.