lib/base_markdown_renderer.rb
class BaseMarkdownRenderer < CommonMarker::HtmlRenderer
def image(node)
src, title = extract_img_attributes(node)
height = extract_image_height(src)
render_img_tag(src, title, height)
end
private
def extract_img_attributes(node)
[
escape_href(node.url),
escape_html(node.title)
]
end
def extract_image_height(src)
query_params = parse_query_params(src)
query_params['cw_image_height']&.first
end
def parse_query_params(url)
parsed_url = URI.parse(url)
CGI.parse(parsed_url.query || '')
rescue URI::InvalidURIError
{}
end
def render_img_tag(src, title, height = nil)
title_attribute = title.present? ? " title=\"#{title}\"" : ''
height_attribute = height ? " height=\"#{height}\" width=\"auto\"" : ''
plain do
# plain ensures that the content is not wrapped in a paragraph tag
out("<img src=\"#{src}\"#{title_attribute}#{height_attribute} />")
end
end
end