title: Ruby on Rails Create Method `uninitialized constant` error for dropdown value
body: <p>I have a form that is rendering properly and yielding the correct values in my server log, but it's hitting an error when I go to create the actual object.</p>
  
  <p>The model is called <code>LeadMagnet</code> and here's the schema:</p>
  
  <pre><code>  create_table "lead_magnets", force: :cascade do |t|
      t.string "title"
      t.text "description"
      t.boolean "motivation", default: false
      t.boolean "mindset", default: false
      t.boolean "resourcing", default: false
      t.boolean "planning", default: false
      t.boolean "time_management", default: false
      t.boolean "discipline", default: false
      t.string "type"
      t.string "link_url"
      t.boolean "active", default: true
      t.bigint "user_id"
      t.datetime "created_at", null: false
      t.datetime "updated_at", null: false
      t.index ["user_id"], name: "index_lead_magnets_on_user_id"
    end
  </code></pre>
  
  <p>The error is being called on my <code>lead_magnet#create</code> method on this line:</p>
  
  <pre><code>@lead_magnet = LeadMagnet.new(lead_magnet_params)
  </code></pre>
  
  <p>And here are the params it's referring to:</p>
  
  <pre><code>def lead_magnet_params
    params.require(:lead_magnet).permit(
      :title,
      :description,
      :motivation,
      :mindset,
      :resourcing,
      :planning,
      :time_management,
      :discipline,
      :type,
      :link_url,
      :active,
      :user_id
    )
  end
  </code></pre>
  
  <p>The issue is for the value for "type", which is a string generated by the following code:</p>
  
  <pre><code>  &lt;div class="form-group col-12 mb-0 pb-0"&gt;
      &lt;%= f.input :type, label: false, prompt: "Select LM Type", input_html: { class: 'mdb-select md-form colorful-select' }, collection: [['Attachment', 'Attachment'], ['Link', 'Link']], required: true %&gt;
    &lt;/div&gt;
  </code></pre>
  
  <p>Which in turn creates this in the server log:</p>
  
  <pre><code>Started POST "/lead_magnets" for ::1 at 2019-10-05 21:11:07 -0700
  Processing by LeadMagnetsController#create as HTML
    Parameters: {"utf8"=&gt;"✓", "authenticity_token"=&gt;"3NYnrPxC6oucYnV25TFOnAmbLjDoRLRisLkbNaisDBV6yCLkg1yXPC6bUo2hzEkrML1VdH+4BY4iLbqgGs0nIg==", "lead_magnet"=&gt;{"title"=&gt;"", "description"=&gt;"", "motivation"=&gt;"0", "mindset"=&gt;"0", "resourcing"=&gt;"0", "planning"=&gt;"0", "time_management"=&gt;"0", "discipline"=&gt;"0", "type"=&gt;"Link", "link_url"=&gt;"", "active"=&gt;"1"}, "commit"=&gt;"Save"}
  Completed 500 Internal Server Error in 3ms (ActiveRecord: 0.0ms)
  
  
  
  NameError - uninitialized constant Link:
    app/controllers/lead_magnets_controller.rb:27:in `create'
  </code></pre>
  
  <p>Why is the value "Link" coming across as an uninitialized constant when it should just be a string value?</p>