Class: DiffTools::SimpleDiff

Inherits:
Object
  • Object
show all
Defined in:
app/lib/diff_tools.rb

Instance Method Summary collapse

Constructor Details

#initialize(old_value, new_value) ⇒ SimpleDiff

Returns a new instance of SimpleDiff.



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# File 'app/lib/diff_tools.rb', line 7

def initialize(old_value, new_value)
  # /\b/ matches word boundaries.
  # It is a zero-length match before and after each word,
  # and it preserves the whitespace between words.
  #
  # "cat dog".split /\b/ == ["cat", " ", "dog"]
  old_value = old_value.to_s.split(/\b/)
  new_value = new_value.to_s.split(/\b/)
  @changes = ::Diff::LCS.sdiff(old_value, new_value).chunk(&:action).map do |action, changes|
    {
      action:,
      old: changes.map(&:old_element).join,
      new: changes.map(&:new_element).join
    }
  end
end

Instance Method Details

#to_html ⇒ Object 



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# File 'app/lib/diff_tools.rb', line 24

def to_html
  @changes.map do |chunk|
    old_html = DiffTools.value_to_html(chunk[:old])
    new_html = DiffTools.value_to_html(chunk[:new])
    if chunk[:action] == "="
      new_html
    else
      (old_html.empty? ? "" : "<del>#{old_html}</del>") + \
        (new_html.empty? ? "" : "<ins>#{new_html}</ins>")
    end
  end.join
end