Scaffolding Demo with Rails 7 and Bootstrap
===

Generate basic stuff with scaffold
---

```sh
rails new demo && cd demo
rails g scaffold Group name:string github_org:string
rails g scaffold Student buckid:integer fname:string lname:string group:references
rails db:migrate
```

It's a working web app! Run `rails server`. Poke around the files:

* Student model already has association, but Group does not
* Add `has_many :students` to Group model
* See controller, views, routes

Create groups in rails console (and/or in browser)

```ruby
> Group.create name: "Blue Jackets", github_org: "arena-district"
> Group.create name: "Columbus Crew", github_org: "mls-cmh"
```

Create students (see error message when group does not exist…)

```ruby
> Student.create buckid: 32423, fname: "Primo", group_id: 1
> Student.create buckid: 32451, fname: "Cher", group: Group.first # alternative, provide group obj instead of id
> Student.create buckid: 44222, lname: "Pantani" # seems to pass, but doen't (returns nil)
> Student.create! buckid:4545, lname: "Pantani", group: Group.last
```

Change landing page by adding a route

```ruby
# config/routes.rb
root to: 'students#index'
```

Improve `students#show` view
---

Better headers for fields

Show group name instead of id (or just group blob):
in `_student.html.erb` partial (`app/views/students/_student.html.erb`):

```erb
<%# the following are possible alternatives for what to show %>
<%= student.group_id %>
<%= student.group %>
<%= student.group.id %>
<%= student.group.name %>
```

Link to group instead of just showing info:

```erb
<%= link_to student.group.name, student.group %>
```

Add links from `groups#index` and `students#index` to the other listing:

```erb
<%# in app/views/students/index.html.erb %>
<%= link_to 'List Groups', groups_path %>

<%# in app/views/groups/index.html.erb %>
<%= link_to 'List Students', students_path %>
```

Improve `students#_form` partial
---

Add a pull-down for entering group info:

```erb
<%# in app/views/students/_form.html.erb %>
<%= form.collection_select :group_id, Group.all, :id, :name %>
<%# alternative: sorts groups alphabetically %>
<%= form.collection_select :group_id, Group.order(:name), :id, :name %>
```

Validations
---

Add to Student model:

```ruby
# app/models/student.rb
validates :buckid, uniqueness: true, presence: true
validates :lname, presence: true
```

Styling with Bootstrap (Best to do this at app creation time!!)
---

See [https://bootrails.com/blog/rails-7-bootstrap-5-tutorial/](https://bootrails.com/blog/rails-7-bootstrap-5-tutorial/)

```sh
# if yarn is not yet installed, enable corepack:
corepack enable

rails new demo --css=bootstrap
```

Add the bootstrap styling
---

_e.g._ change `groups#index` view:

```erb
<%# in app/views/groups/index.html.erb %>
<%= link_to "Show this group", group, class: 'btn btn-secondary' %>
...
<%= link_to "New group", new_group_path, class: 'btn btn-primary' %>
```

change `groups#_group` partial:

```erb
<%# in app/views/groups/_group.html.erb %>
<div id="<%= dom_id group %>" class="card mx-auto w-75">

  <div class="card-body">
...
  </div>
```

Seed the database using faker
---

Add faker gem to Gemfile (ok to put just inside group :development)

```ruby
bundle add 'faker'
```

In `db/seeds.rb`:

```ruby
6.times do
  group = Group.create!(name: Faker::Company.name,
                        github_org: Faker::Internet.slug)
  5.times do
    group.students.create!(buckid: Faker::Number.unique.number(digits: 9),
                           fname: Faker::Name.first_name,
                           lname: Faker::Name.last_name)
  end
end
```

```sh
rails db:seed
```