51 lines
1.0 KiB
Ruby
51 lines
1.0 KiB
Ruby
|
# Generates a table of contents based on markdown headers in the body
|
||
|
|
#
|
||
|
|
# The block's arg may be an int describing the maximum depth at which
|
||
|
|
# headers are added to the toc
|
||
|
|
|
||
|
|
class TocMakerBlock < Liquid::Block
|
||
|
|
# include Enumerable
|
||
|
|
|
||
|
|
def initialize(tag_name, arg, tokens)
|
||
|
|
super
|
||
|
|
@max_depth = arg.to_s.empty? ? 100 : arg.to_i
|
||
|
|
@body = tokens
|
||
|
|
end
|
||
|
|
|
||
|
|
def to_internal_link(header)
|
||
|
|
url = header.downcase.gsub(/\s+/, "-")
|
||
|
|
|
||
|
|
"[#{header}](##{url})"
|
||
|
|
end
|
||
|
|
|
||
|
|
def render(context)
|
||
|
|
|
||
|
|
contents = @body.render(context)
|
||
|
|
|
||
|
|
|
||
|
|
headers = contents.lines.map {|l|
|
||
|
|
if /^(#+)\s+(\S.*)$/ =~ l
|
||
|
|
[$1.length, $2]
|
||
|
|
end
|
||
|
|
}.compact
|
||
|
|
|
||
|
|
min_indent = headers.min_by {|t| t[0]}[0]
|
||
|
|
|
||
|
|
headers = headers.map {|t|
|
||
|
|
actual_depth = t[0] - min_indent
|
||
|
|
if actual_depth < @max_depth then
|
||
|
|
|
||
|
|
indent = " " * actual_depth
|
||
|
|
|
||
|
|
"#{indent}* #{to_internal_link(t[1])}"
|
||
|
|
end
|
||
|
|
}.compact
|
||
|
|
|
||
|
|
headers.unshift("### Table Of Contents\n")
|
||
|
|
|
||
|
|
headers.join("\n") + contents
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
|
||
|
|
Liquid::Template.register_tag('tocmaker', TocMakerBlock)
|