plateforme-tfjm2/registration/templates/registration/signup.html

<!-- templates/signup.html -->
{% extends 'base.html' %}
{% load crispy_forms_filters %}
{% load i18n %}
{% block title %}{% trans "Sign up" %}{% endblock %}

{% block extracss %}
    {{ student_registration_form.media }}
{% endblock %}

{% block content %}
    <h2>{% trans "Sign up" %}</h2>

    <form method="post">
        {% csrf_token %}
        {{ form|crispy }}
        <div id="registration_form"></div>
        <button class="btn btn-success" type="submit">
            {% trans "Sign up" %}
        </button>
    </form>

    <div id="student_registration_form" class="d-none">
        {{ student_registration_form|crispy }}
    </div>
    <div id="coach_registration_form" class="d-none">
        {{ coach_registration_form|crispy }}
    </div>
{% endblock %}

{% block extrajavascript %}
    <script>
        document.addEventListener('DOMContentLoaded', () => {
            let role_elem = document.getElementById("id_role")
            function updateView () {
                let selected_role = role_elem.options[role_elem.selectedIndex].value
                if (selected_role === "participant")
                    document.getElementById("registration_form").innerHTML = document.getElementById("student_registration_form").innerHTML
                else
                    document.getElementById("registration_form").innerHTML = document.getElementById("coach_registration_form").innerHTML
            }
            role_elem.addEventListener('change', updateView)
            updateView()
        })
    </script>
{% endblock %}