form.html

<html><body>
<center>
  <h2>Form</h2>
  <p>Welcome, Current system DateTime is {{data.date}}.</p>

  {% if data.filled %}
    <p>Your content has been written to {{ data.file }}</p>
  {% endif %}

  <form action="{{ url_for('writetofile') }}" method=post>
    <label>What do you want to write to the file?</lable>
    <textarea name=content cols=60 rows=10 placeholder='Write here > Press submit'>
    </textarea>

    <input type=submit value='Lets Go!'>
  </form> 
</center>
</html></body>