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# frozen_string_literal: true
module XPath
class Renderer
def self.render(node, type)
new(type).render(node)
end
def initialize(type)
@type = type
end
def render(node)
arguments = node.arguments.map { |argument| convert_argument(argument) }
send(node.expression, *arguments)
end
def convert_argument(argument)
case argument
when Expression, Union then render(argument)
when Array then argument.map { |element| convert_argument(element) }
when String then string_literal(argument)
when Literal then argument.value
else argument.to_s
end
end
def string_literal(string)
if string.include?("'")
string = string.split("'", -1).map do |substr|
"'#{substr}'"
end.join(%q(,"'",))
"concat(#{string})"
else
"'#{string}'"
end
end
def this_node
'.'
end
def descendant(current, element_names)
with_element_conditions("#{current}//", element_names)
end
def child(current, element_names)
with_element_conditions("#{current}/", element_names)
end
def axis(current, name, element_names)
with_element_conditions("#{current}/#{name}::", element_names)
end
def anywhere(element_names)
with_element_conditions('//', element_names)
end
def where(on, condition)
"#{on}[#{condition}]"
end
def attribute(current, name)
if valid_xml_name?(name)
"#{current}/@#{name}"
else
"#{current}/attribute::*[local-name(.) = #{string_literal(name)}]"
end
end
def binary_operator(name, left, right)
"(#{left} #{name} #{right})"
end
def is(one, two)
if @type == :exact
binary_operator('=', one, two)
else
function(:contains, one, two)
end
end
def variable(name)
"%{#{name}}"
end
def text(current)
"#{current}/text()"
end
def literal(node)
node
end
def css(current, selector)
paths = Nokogiri::CSS.xpath_for(selector).map do |xpath_selector|
"#{current}#{xpath_selector}"
end
union(paths)
end
def union(*expressions)
expressions.join(' | ')
end
def function(name, *arguments)
"#{name}(#{arguments.join(', ')})"
end
private
def with_element_conditions(expression, element_names)
if element_names.length == 1
"#{expression}#{element_names.first}"
elsif element_names.length > 1
"#{expression}*[#{element_names.map { |e| "self::#{e}" }.join(' | ')}]"
else
"#{expression}*"
end
end
def valid_xml_name?(name)
name =~ /^[a-zA-Z_:][a-zA-Z0-9_:\.\-]*$/
end
end
end
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