{% set sourceLevel = (sourceLevel is defined ? sourceLevel : 1) -%}

<ul data-level="{{ sourceLevel }}">
	{% for key, source in sources %}
		{% if source.heading is defined %}
			<li class="heading"><span>{{ source.heading }}</span></li>
		{% else %}
			<li>
				<a data-key="{{ key }}"
					{%- if source.hasThumbs is defined and source.hasThumbs %} data-has-thumbs="1"{% endif %}
					{%- if source.structureId is defined and source.structureId %} data-has-structure="1" data-structure-id="{{ source.structureId }}"{% endif %}
					{%- if source.data is defined -%}
						{% for dataKey, dataVal in source.data %} data-{{ dataKey }}="{{ dataVal }}"{% endfor %}
					{%- endif -%}
				>{{ source.label }}</a>
				{% if source.nested is defined and source.nested is not empty %}
					<div class="toggle"></div>
					{% include "_elements/sources" with {
						sources: source.nested,
						sourceLevel: sourceLevel + 1
					} %}
				{% endif %}
			</li>
		{% endif %}
	{% endfor %}
</ul>