# frozen_string_literal: true require 'cgi' # Produce a simple HTML diff view. class Diff::LCS::HTMLDiff class << self attr_accessor :can_expand_tabs #:nodoc: end self.can_expand_tabs = true class Callbacks #:nodoc: attr_accessor :output attr_accessor :match_class attr_accessor :only_a_class attr_accessor :only_b_class def initialize(output, options = {}) @output = output options ||= {} @match_class = options[:match_class] || 'match' @only_a_class = options[:only_a_class] || 'only_a' @only_b_class = options[:only_b_class] || 'only_b' end def htmlize(element, css_class) element = ' ' if element.empty? %Q(
#{element}
\n) end private :htmlize # This will be called with both lines are the same def match(event) @output << htmlize(event.old_element, :match_class) end # This will be called when there is a line in A that isn't in B def discard_a(event) @output << htmlize(event.old_element, :only_a_class) end # This will be called when there is a line in B that isn't in A def discard_b(event) @output << htmlize(event.new_element, :only_b_class) end end DEFAULT_OPTIONS = { :expand_tabs => nil, :output => nil, :css => nil, :title => nil }.freeze DEFAULT_CSS = <<-CSS body { margin: 0; } .diff { border: 1px solid black; margin: 1em 2em; } p { margin-left: 2em; } pre { padding-left: 1em; margin: 0; font-family: Inconsolata, Consolas, Lucida, Courier, monospaced; white-space: pre; } .match { } .only_a { background-color: #fdd; color: red; text-decoration: line-through; } .only_b { background-color: #ddf; color: blue; border-left: 3px solid blue } h1 { margin-left: 2em; } CSS def initialize(left, right, options = nil) @left = left @right = right @options = options @options = DEFAULT_OPTIONS.dup if @options.nil? end def verify_options @options[:expand_tabs] ||= 4 @options[:expand_tabs] = 4 if @options[:expand_tabs].negative? @options[:output] ||= $stdout @options[:css] ||= DEFAULT_CSS.dup @options[:title] ||= 'diff' end private :verify_options attr_reader :options def run verify_options if @options[:expand_tabs].positive? && self.class.can_expand_tabs formatter = Text::Format.new formatter.tabstop = @options[:expand_tabs] @left.map! do |line| formatter.expand(line.chomp) end @right.map! do |line| formatter.expand(line.chomp) end end @left.map! do |line| CGI.escapeHTML(line.chomp) end @right.map! do |line| CGI.escapeHTML(line.chomp) end @options[:output] << <<-OUTPUT #{@options[:title]}

#{@options[:title]}

Legend: Only in Old  Only in New

OUTPUT callbacks = Callbacks.new(@options[:output]) Diff::LCS.traverse_sequences(@left, @right, callbacks) @options[:output] << <<-OUTPUT
OUTPUT end end