Files
danbooru/app/presenters/wiki_page_presenter.rb
2018-05-10 11:18:02 -07:00

63 lines
1.7 KiB
Ruby

class WikiPagePresenter
attr_reader :wiki_page
def initialize(wiki_page)
@wiki_page = wiki_page
end
def excerpt
wiki_page.body
end
# Produce a formatted page that shows the difference between two versions of a page.
def diff(other_version)
pattern = Regexp.new('(?:<.+?>)|(?:[0-9_A-Za-z\x80-\xff]+[\x09\x20]?)|(?:[ \t]+)|(?:\r?\n)|(?:.+?)')
thisarr = self.body.scan(pattern)
otharr = other_version.body.scan(pattern)
cbo = Diff::LCS::ContextDiffCallbacks.new
diffs = thisarr.diff(otharr, cbo)
escape_html = ->(str) {str.gsub(/&/,'&amp;').gsub(/</,'&lt;').gsub(/>/,'&gt;')}
output = thisarr;
output.each { |q| q.replace(CGI.escape_html(q)) }
diffs.reverse_each do |hunk|
newchange = hunk.max{|a,b| a.old_position <=> b.old_position}
newstart = newchange.old_position
oldstart = hunk.min{|a,b| a.old_position <=> b.old_position}.old_position
if newchange.action == '+'
output.insert(newstart, "</ins>")
end
hunk.reverse_each do |chg|
case chg.action
when '-'
oldstart = chg.old_position
output[chg.old_position] = "" if chg.old_element.match(/^\r?\n$/)
when '+'
if chg.new_element.match(/^\r?\n$/)
output.insert(chg.old_position, "[nl]")
else
output.insert(chg.old_position, "#{escape_html[chg.new_element]}")
end
end
end
if newchange.action == '+'
output.insert(newstart, "<ins>")
end
if hunk[0].action == '-'
output.insert((newstart == oldstart || newchange.action != '+') ? newstart+1 : newstart, "</del>")
output.insert(oldstart, "<del>")
end
end
output.join.gsub(/\r?\n/, "[nl]")
end
end