mastodon/app/views/home/index.html.haml

= simple_form_for Status.new, url: statuses_path, method: :post do |f|
  = f.input :text, required: true, autofocus: true, label: false, placeholder: 'What are you up to?'

  .form-actions
    = f.button :submit, 'Post update'

- content_for :raw_content do
  .activity-stream.activity-stream-embedded
    - @timeline.each do |status|
      = render partial: 'stream_entries/status', locals: { status: status }