lib/qiita/markdown/filters/checkbox.rb
module Qiita
module Markdown
module Filters
# Converts [ ] and [x] into checkbox elements.
#
# * [x] Foo
# * [ ] Bar
# * [ ] Baz
#
class Checkbox < HTML::Pipeline::Filter
def call
doc.search("li").each do |li|
list = List.new(li)
list.convert if list.has_checkbox?
end
doc
end
class List
include Mem
CHECKBOX_CLOSE_MARK = "[x] "
CHECKBOX_OPEN_MARK = "[ ] "
def initialize(node)
@node = node
end
def has_checkbox?
has_open_checkbox? || has_close_checkbox?
end
def convert
first_text_node.content = first_text_node.content.sub(checkbox_mark, "").lstrip
first_text_node.add_previous_sibling(checkbox_node)
@node["class"] = "task-list-item"
end
private
def checkbox_mark
case
when has_close_checkbox?
CHECKBOX_CLOSE_MARK
when has_open_checkbox?
CHECKBOX_OPEN_MARK
end
end
def checkbox_node
node = Nokogiri::HTML.fragment('<input type="checkbox" class="task-list-item-checkbox">')
node.children.first["checked"] = true if has_close_checkbox?
node.children.first["disabled"] = true
node
end
def first_text_node
is_loose_list_node = @node.children.first&.text == "\n" && @node.children[1]&.name == "p"
if is_loose_list_node
@node.children[1].children.first
elsif @node.children.first && @node.children.first.name == "p"
@node.children.first.children.first
else
@node.children.first
end
end
memoize :first_text_node
def has_close_checkbox?
!!first_text_node && first_text_node.text? && first_text_node.content.start_with?(CHECKBOX_CLOSE_MARK)
end
memoize :has_close_checkbox?
def has_open_checkbox?
!!first_text_node && first_text_node.text? && first_text_node.content.start_with?(CHECKBOX_OPEN_MARK)
end
memoize :has_open_checkbox?
end
end
end
end
end