Method: HTML::Selector#match

Defined in:
lib/action_controller/vendor/html-scanner/html/selector.rb

#match(element, first_only = false) ⇒ Object

:call-seq:

match(element, first?) => array or nil

Matches an element against the selector.

For a simple selector this method returns an array with the element if the element matches, nil otherwise.

For a complex selector (sibling and descendant) this method returns an array with all matching elements, nil if no match is found.

Use first_only=true if you are only interested in the first element.

For example:

if selector.match(element)
  puts "Element is a login form"
end



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# File 'lib/action_controller/vendor/html-scanner/html/selector.rb', line 363

def match(element, first_only = false)
  # Match element if no element name or element name same as element name
  if matched = (!@tag_name || @tag_name == element.name)
    # No match if one of the attribute matches failed
    for attr in @attributes
      if element.attributes[attr[0]] !~ attr[1]
        matched = false
        break
      end
    end
  end

  # Pseudo class matches (nth-child, empty, etc).
  if matched
    for pseudo in @pseudo
      unless pseudo.call(element)
        matched = false
        break
      end
    end
  end

  # Negation. Same rules as above, but we fail if a match is made.
  if matched && @negation
    for negation in @negation
      if negation[:tag_name] == element.name
        matched = false
      else
        for attr in negation[:attributes]
          if element.attributes[attr[0]] =~ attr[1]
            matched = false
            break
          end
        end
      end
      if matched
        for pseudo in negation[:pseudo]
          if pseudo.call(element)
            matched = false
            break
          end
        end
      end
      break unless matched
    end
  end

  # If element matched but depends on another element (child,
  # sibling, etc), apply the dependent matches instead.
  if matched && @depends
    matches = @depends.call(element, first_only)
  else
    matches = matched ? [element] : nil
  end

  # If this selector is part of the group, try all the alternative
  # selectors (unless first_only).
  if !first_only || !matches
    @alternates.each do |alternate|
      break if matches && first_only
      if subset = alternate.match(element, first_only)
        if matches
          matches.concat subset
        else
          matches = subset
        end
      end
    end
  end

  matches
end