Class: Slimmer::Processors::TagMover

Inherits:
Object
  • Object
show all
Defined in:
lib/slimmer/processors/tag_mover.rb

Instance Method Summary collapse

Instance Method Details

#filter(src, dest) ⇒ Object 



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# File 'lib/slimmer/processors/tag_mover.rb', line 3

def filter(src, dest)
  move_tags(src, dest, "link",   must_have: %w[href])
  move_tags(src, dest, "meta",   must_have: %w[name content], keys: %w[name content http-equiv], insertion_location: :top)
  move_tags(src, dest, "meta",   must_have: %w[property content], keys: %w[property content], insertion_location: :top)
  move_tags(src, dest, "base",   must_have: %w[href])
  move_tags(src, dest, "script", keys: %w[src inner_html], head_if_attributes: %w[async defer])
end

#head_or_body(node, head_if_attributes) ⇒ Object 



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# File 'lib/slimmer/processors/tag_mover.rb', line 34

def head_or_body(node, head_if_attributes)
  if head_if_attributes.any? { |attribute| node.has_attribute?(attribute) }
    "head"
  else
    "body"
  end
end

#include_tag?(node, min_attrs) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/slimmer/processors/tag_mover.rb', line 11

def include_tag?(node, min_attrs)
  min_attrs.inject(true) { |all_okay, attr_name| all_okay && node.has_attribute?(attr_name) }
end

#move_tags(src, dest, type, opts) ⇒ Object 



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# File 'lib/slimmer/processors/tag_mover.rb', line 42

def move_tags(src, dest, type, opts)
  comparison_attrs = opts[:keys] || opts[:must_have]
  min_attrs = opts[:must_have] || []
  head_if_attributes = opts[:head_if_attributes] || []
  dest_node = "head"
  already_there = dest.css(type).map { |node|
    tag_fingerprint(node, comparison_attrs)
  }.compact

  src.css(type).each do |node|
    next unless include_tag?(node, min_attrs) && !already_there.include?(tag_fingerprint(node, comparison_attrs))

    node = wrap_node(src, node)
    if head_if_attributes.any?
      dest_node = head_or_body(node, head_if_attributes)
      insert_at_top = true if dest_node == "head"
    end
    node.remove

    if opts[:insertion_location] == :top || insert_at_top
      dest.at_xpath("/html/#{dest_node}").prepend_child(node)
    else
      dest.at_xpath("/html/#{dest_node}") << node
    end
  end
end

#tag_fingerprint(node, attrs) ⇒ Object 



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# File 'lib/slimmer/processors/tag_mover.rb', line 15

def tag_fingerprint(node, attrs)
  collected_attrs = attrs.collect do |attr_name|
    if attr_name == "inner_html"
      node.content
    else
      node.has_attribute?(attr_name) ? node.attr(attr_name) : nil
    end
  end

  collected_attrs.compact.sort
end

#wrap_node(src, node) ⇒ Object 



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# File 'lib/slimmer/processors/tag_mover.rb', line 27

def wrap_node(src, node)
  if node.previous_sibling.to_s =~ /<!--\[if[^\]]+\]><!-->/ && node.next_sibling.to_s == "<!--<![endif]-->"
    node = Nokogiri::XML::NodeSet.new(src, [node.previous_sibling, node, node.next_sibling])
  end
  node
end