{% for slide in page.slides %} {% assign url_first_char = slide.url | slice: 0 %} {%- if slide.url contains 'https://' or slide.url contains 'http://' or url_first_char == '.' or url_first_char == '/' -%} {%- assign slide_url = slide.url -%} {%- else -%} {%- assign slide_url = slide.url | prepend: page.baseurl -%} {%- endif -%} {% endfor %}