Error handling for checked fields Django multiselectfield

Question

I have a conditional check where I need to look at a certain checkbox, and depending on that, a multiselect field becomes required.

I have something similar in place:

{% for value, text in form.customfield.field.choices %}
<div class="checkbox custom-control custom-checkbox list-inline-item" style="display:inline-flex;">
    <input type="checkbox" name="{{customfield.name}}" value="{{value}}" class="list-inline-item custom-control-input" title="" id="id_{{value}}"  {% if value in customfield.data %} checked="checked"{% endif %}>
    <label for="id_{{value}}" class="form-check-label custom-control-label mr-3">{{text}}</label>
</div>
{% endfor %}

Is there a way to do error handling for this? I verified that my form.is_valid() returns false, but the error message does not get displayed, like it does for inputs/textboxes. I'm assuming I need to print the specific error out in the template explicitly, as I am not using defaults like {{ form.customfield }} or {{ bootstrap_field }}

form.is_valid() returns False.

form._errors gives me:

 <ul class="errorlist"><li>customfield<ul class="errorlist"><li>This field is required when the other field is checked.</li></ul>

Answer 1

Rant: As with many other Django questions I've asked, I had to post my own answer. End Rant!

Along with the above check, just loop through the field.errors and display the error Note: invalid-feedback is used to hide/display the error message in Bootstrap4, so

<div id="id_{{customfield.name}}" class="list-inline-item {% if customfield.errors %} is-invalid{% endif %}">
        {% for value, text in form.customfield.field.choices %}
        <div class="checkbox custom-control custom-checkbox list-inline-item">
            <input type="checkbox" name="{{customfield.name}}" value="{{value}}" class="list-inline-item custom-control-input" title="" id="id_{{value}}"  {% if value in customfield.data %} checked="checked"{% endif %}>
            <label for="id_{{value}}" class="form-check-label custom-control-label">{{text}}</label>
        </div>
        {% endfor %}
</div>

{% if customfield.errors %}
  <div class="invalid-feedback">
    {% for error in customfield.errors %} {{ error }} {% endfor %}
  </div>
{% endif %}