How do I set value to hidden integerfield in WTForms - flask

Question

I have a form which needs to take in 1 integer value. This integer value will be an id associated with a row in a html table.
template.html
{% block content %}
<div id="formContainer" class="center top">
<p class="lead">Select simulation session </p>
{% if simulationSessions %}
<table class="table table-striped">
<thead>
<tr>
<th></th>
<th>#</th>
<th>Label</th>
<th>Date</th>
</tr>
</thead>
<tbody>
{% for simulationSession in simulationSessions %}
<tr>
<td><input id="id-{{ simulationSession.id }}" name="idRadio" type="radio" value="{{ simulationSession.id }}"> </td>
<td>{{ simulationSession.id }}</td>
<td>{{ simulationSession.label }}</td>
<td>{{ simulationSession.date.strftime('%d-%m-%y %H:%M') }}</td>
</tr>
{% endfor %}
</tbody>
</table>
<button type="button" class="btn btn-sm btn-success">Analyse</button>
{% else %}
<div class="alert alert-danger" role="alert">
<strong>Oopsadazy!</strong> No simulations are registered in the database for this user. You need to run a simulation session before analyzing it!
</div>
{% endif %}
</div>
{% endblock %}
Each table row has a radio button, and the value from the selected button will be the only thing my form requires. I have decided to go with one hidden IntegerField instead of a RadioField. It is possible to do the latter but then I have to solve the problem of dynamically creating the choices (I decided to go against that when I couldn't pass the list as a parameter when referencing the form from my view.py).
form.py
class SimulationSessionSelectionForm(Form):
simulationSessoinId = IntegerField('simulationSessoinId', validators=[DataRequired()], widget=HiddenInput())
My questions is how can I take the value from the selected radio button and use that as the data for the hidden integer field once the form is submitted?
This could maybe be done with something similar to this inside a script within the html? (this does not compile)
{% set form.id.data %}
this.value
{% endset %}
The view would look something like this:
view.py
#app.route('/dashboard', methods=['GET', 'POST'])
#login_required
def dashboard():
form = SimulationSessionSelectionForm()
if form.validate_on_submit():
redirect('/somewhere')
userkey = models.User.query.filter_by(id = current_user.get_id()).first().userKey
userSimulationSessions = models.SimulationSession.query.filter_by(userKey = userkey).all()
simulationSessions = []
simulationSessionIds = []
for simulation in userSimulationSessions:
simulationSessions.append({'id' : simulation.sessionID, 'label' : simulation.label, 'date' : simulation.date})
simulationSessionIds.append(simulation.sessionID)
return render_template("dashboard.html", simulationSessions = simulationSessions, form = form)

Answer 1

This line in the template adds the hidden field (and the csfr token) to the
{{ form.hidden_tag() }}
I figured I could just set the value of the hidden IntegerField by some jquery script whenever the radio button change event fired. To do this I used the following code:
<script>
$( document ).ready(function() {
$('input[type=radio][name=idRadio]').change(function() {
$('#simulationSessoinId').val(this.value)
});
});
</script>