JezK
Edit File: searchable.rb
# coding: utf-8 # frozen_string_literal: true module Nokogiri module XML # # The Searchable module declares the interface used for searching your DOM. # # It implements the public methods #search, #css, and #xpath, # as well as allowing specific implementations to specialize some # of the important behaviors. # module Searchable # Regular expression used by Searchable#search to determine if a query # string is CSS or XPath LOOKS_LIKE_XPATH = %r{^(\./|/|\.\.|\.$)} # :section: Searching via XPath or CSS Queries ### # call-seq: # search(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class]) # # Search this object for +paths+. +paths+ must be one or more XPath or CSS queries: # # node.search("div.employee", ".//title") # # A hash of namespace bindings may be appended: # # node.search('.//bike:tire', {'bike' => 'http://schwinn.com/'}) # node.search('bike|tire', {'bike' => 'http://schwinn.com/'}) # # For XPath queries, a hash of variable bindings may also be appended to the namespace # bindings. For example: # # node.search('.//address[@domestic=$value]', nil, {:value => 'Yes'}) # # 💡 Custom XPath functions and CSS pseudo-selectors may also be defined. To define custom # functions create a class and implement the function you want to define. The first argument # to the method will be the current matching NodeSet. Any other arguments are ones that you # pass in. Note that this class may appear anywhere in the argument list. For example: # # handler = Class.new { # def regex node_set, regex # node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ } # end # }.new # node.search('.//title[regex(., "\w+")]', 'div.employee:regex("[0-9]+")', handler) # # See Searchable#xpath and Searchable#css for further usage help. def search(*args) paths, handler, ns, binds = extract_params(args) xpaths = paths.map(&:to_s).map do |path| LOOKS_LIKE_XPATH.match?(path) ? path : xpath_query_from_css_rule(path, ns) end.flatten.uniq xpath(*(xpaths + [ns, handler, binds].compact)) end alias_method :/, :search ### # call-seq: # at(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class]) # # Search this object for +paths+, and return only the first # result. +paths+ must be one or more XPath or CSS queries. # # See Searchable#search for more information. def at(*args) search(*args).first end alias_method :%, :at ### # call-seq: # css(*rules, [namespace-bindings, custom-pseudo-class]) # # Search this object for CSS +rules+. +rules+ must be one or more CSS # selectors. For example: # # node.css('title') # node.css('body h1.bold') # node.css('div + p.green', 'div#one') # # A hash of namespace bindings may be appended. For example: # # node.css('bike|tire', {'bike' => 'http://schwinn.com/'}) # # 💡 Custom CSS pseudo classes may also be defined which are mapped to a custom XPath # function. To define custom pseudo classes, create a class and implement the custom pseudo # class you want defined. The first argument to the method will be the matching context # NodeSet. Any other arguments are ones that you pass in. For example: # # handler = Class.new { # def regex(node_set, regex) # node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ } # end # }.new # node.css('title:regex("\w+")', handler) # # 💡 Some XPath syntax is supported in CSS queries. For example, to query for an attribute: # # node.css('img > @href') # returns all +href+ attributes on an +img+ element # node.css('img / @href') # same # # # ⚠ this returns +class+ attributes from all +div+ elements AND THEIR CHILDREN! # node.css('div @class') # # node.css # # 💡 Array-like syntax is supported in CSS queries as an alternative to using +:nth-child()+. # # ⚠ NOTE that indices are 1-based like +:nth-child+ and not 0-based like Ruby Arrays. For # example: # # # equivalent to 'li:nth-child(2)' # node.css('li[2]') # retrieve the second li element in a list # # ⚠ NOTE that the CSS query string is case-sensitive with regards to your document type. HTML # tags will match only lowercase CSS queries, so if you search for "H1" in an HTML document, # you'll never find anything. However, "H1" might be found in an XML document, where tags # names are case-sensitive (e.g., "H1" is distinct from "h1"). def css(*args) rules, handler, ns, _ = extract_params(args) css_internal(self, rules, handler, ns) end ## # call-seq: # at_css(*rules, [namespace-bindings, custom-pseudo-class]) # # Search this object for CSS +rules+, and return only the first # match. +rules+ must be one or more CSS selectors. # # See Searchable#css for more information. def at_css(*args) css(*args).first end ### # call-seq: # xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class]) # # Search this node for XPath +paths+. +paths+ must be one or more XPath # queries. # # node.xpath('.//title') # # A hash of namespace bindings may be appended. For example: # # node.xpath('.//foo:name', {'foo' => 'http://example.org/'}) # node.xpath('.//xmlns:name', node.root.namespaces) # # A hash of variable bindings may also be appended to the namespace bindings. For example: # # node.xpath('.//address[@domestic=$value]', nil, {:value => 'Yes'}) # # 💡 Custom XPath functions may also be defined. To define custom functions create a class and # implement the function you want to define. The first argument to the method will be the # current matching NodeSet. Any other arguments are ones that you pass in. Note that this # class may appear anywhere in the argument list. For example: # # handler = Class.new { # def regex(node_set, regex) # node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ } # end # }.new # node.xpath('.//title[regex(., "\w+")]', handler) # def xpath(*args) paths, handler, ns, binds = extract_params(args) xpath_internal(self, paths, handler, ns, binds) end ## # call-seq: # at_xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class]) # # Search this node for XPath +paths+, and return only the first # match. +paths+ must be one or more XPath queries. # # See Searchable#xpath for more information. def at_xpath(*args) xpath(*args).first end # :call-seq: # >(selector) → NodeSet # # Search this node's immediate children using CSS selector +selector+ def >(selector) # rubocop:disable Naming/BinaryOperatorParameterName ns = (document.root&.namespaces || {}) xpath(CSS.xpath_for(selector, prefix: "./", ns: ns).first) end # :section: private def css_internal(node, rules, handler, ns) xpath_internal(node, css_rules_to_xpath(rules, ns), handler, ns, nil) end def xpath_internal(node, paths, handler, ns, binds) document = node.document return NodeSet.new(document) unless document if paths.length == 1 return xpath_impl(node, paths.first, handler, ns, binds) end NodeSet.new(document) do |combined| paths.each do |path| xpath_impl(node, path, handler, ns, binds).each { |set| combined << set } end end end def xpath_impl(node, path, handler, ns, binds) ctx = XPathContext.new(node) ctx.register_namespaces(ns) path = path.gsub(/xmlns:/, " :") unless Nokogiri.uses_libxml? binds&.each do |key, value| ctx.register_variable(key.to_s, value) end ctx.evaluate(path, handler) end def css_rules_to_xpath(rules, ns) rules.map { |rule| xpath_query_from_css_rule(rule, ns) } end def xpath_query_from_css_rule(rule, ns) visitor = Nokogiri::CSS::XPathVisitor.new( builtins: Nokogiri::CSS::XPathVisitor::BuiltinsConfig::OPTIMAL, doctype: document.xpath_doctype, ) self.class::IMPLIED_XPATH_CONTEXTS.map do |implied_xpath_context| CSS.xpath_for(rule.to_s, { prefix: implied_xpath_context, ns: ns, visitor: visitor, }) end.join(" | ") end def extract_params(params) # :nodoc: handler = params.find do |param| ![Hash, String, Symbol].include?(param.class) end params -= [handler] if handler hashes = [] while Hash === params.last || params.last.nil? hashes << params.pop break if params.empty? end ns, binds = hashes.reverse ns ||= (document.root&.namespaces || {}) [params, handler, ns, binds] end end end end