Use freshly generated non static file in template

Phoenix Forum Questions / Help
1

I generate a qr code (that I plan to use in the template) on fly in my controller.

def rapport(conn, _params) do
  {:ok, response} = HTTPoison.get 'http://localhost:8080/quiz/filter/1/count/2'
  quizes = process_response(response)
  Enum.each(quizes, & Qr.create_qr_code(@qr_folder <> &1.unique_id))
  render(conn, "quiz.html", quizes: quizes)
end

The mentioned template looks as:

<%= for quiz <- @quizes do %>
  <div class="page-break">
    <img src="http://localhost:4000/qr/<%= quiz.unique_id %>" />
    <ul>
      <%= for qa <- quiz.question_answers do %>
        <%= qa.question %>
        <ul>
          <%= for answer <- qa.answers do %>
            <li>
              <%= answer %>
            </li>
          <% end %>
        </ul>
      <% end %>
    </ul>
  </div>
<% end %>

The problem is, that freshly generated qr code is not displayed in the rendered page. However, if I replace

<img src="http://localhost:4000/qr/<%= quiz.unique_id %>" />

with

<img src='http://localhost:4000/qr/09a588dcfeaa4d2a8fb45d290a6ba6d1' />

(09a588dcfeaa4d2a8fb45d290a6ba6d1 is an image generated in previous try) than qr code is shown.

Any idea what could be wrong?

2

OK, figured out by myself. The problem is the png library doesn’t close the file. Thus, the needed file wasn’t ready at the time.

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