Looseleaf Framework

Checkbox: Error 

<div class="field field--error">
    <input type="checkbox" id="tos" name="tos" aria-describedby="tos-error" aria-invalid="true" />
    <label for="tos">I agree to the Terms of Service</label>
    <p class="field__error" id="tos-error">
        <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" fill="currentColor" viewBox="0 0 16 16">
            <path d="M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0zM8 4a.905.905 0 0 0-.9.995l.35 3.507a.552.552 0 0 0 1.1 0l.35-3.507A.905.905 0 0 0 8 4zm.002 6a1 1 0 1 0 0 2 1 1 0 0 0 0-2z" />
        </svg>
        You must agree to the terms of service to use this website.
    </p>
</div>
 
{% if ariaDescribedby === false %}
    {% set ariaDescribedby = '' %}
    {% if hint %}
        {% set ariaDescribedby = name + '-hint' %}
    {% elif error %}
        {% set ariaDescribedby = name + '-error' %}
    {% elif hint and error %}
        {% set ariaDescribedby = name + '-hint' + " " + name + '-error' %}
    {% endif %}
{% endif %}

<div class="field{% if error %} field--error{% endif %}">
    <input type="checkbox" id="{{ id if id else name }}" name="{{ name }}"{% if value %} value="{{ value }}"{% endif %}{% if ariaDescribedby and ariaDescribedby != '' %} aria-describedby="{{ ariaDescribedby }}"{% endif %}{% if error or invalid %} aria-invalid="true"{% endif %} />
    <label for="{{ id if id else name }}">{{ label }}</label>
    {%- if hint %}
    {% render '@hint', { name: name, content: hint } %}
    {%- endif %}
    {%- if error %}
    {% render '@error', { name: name, content: error } %}
    {%- endif -%}
</div>
 
{
  "name": "tos",
  "id": false,
  "label": "I agree to the Terms of Service",
  "ariaDescribedby": false,
  "hint": false,
  "error": "You must agree to the terms of service to use this website.",
  "invalid": false
}

Checkbox

Checkboxes are visually hidden and replaced with custom style via pseudo content attached to the adjacent label:

input[type="checkbox"] {
    clip: rect(0 0 0 0);
    clip-path: inset(50%);
    height: 1px;
    overflow: hidden;
    position: absolute;
    white-space: nowrap;
    width: 1px;
}

input[type="checkbox"] + label::before {
    /* Custom checkbox style. */
}

Labels and the corresponding checkbox element are intended to be wrapped in a containing element with a class of field.

A hint can be added immediately after the <label> in a paragraph with a class of field__hint.

A validation error message can be added immediately after the <label> or hint in a paragraph with a class of field__error.

Hints and validation error messages must be associated with the checkbox using unique IDs which can be referenced from the checkbox’s aria-describedby attribute. For more information, see WebAIM’s form validation error documentation.

Checkboxes with an associated error should also be given an aria-invalid attribute of true.