module Nokogiri::XML::Searchable

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.

Constants

LOOKS_LIKE_XPATH

Regular expression used by Searchable#search to determine if a query string is CSS or XPath

Searching via XPath or CSS Queries

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Public Instance Methods

%(*args)
Alias for: at
/(*args)
Alias for: search
>(selector) β†’ NodeSet click to toggle source

Search this node’s immediate children using CSS selector selector

# File lib/nokogiri/xml/searchable.rb, line 196
def >(selector) # rubocop:disable Naming/BinaryOperatorParameterName
  ns = (document.root&.namespaces || {})
  xpath(CSS.xpath_for(selector, prefix: "./", ns: ns).first)
end
at(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class]) click to toggle source

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.

# File lib/nokogiri/xml/searchable.rb, line 71
def at(*args)
  search(*args).first
end
Also aliased as: %
at_css(*rules, [namespace-bindings, custom-pseudo-class]) click to toggle source

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.

# File lib/nokogiri/xml/searchable.rb, line 140
def at_css(*args)
  css(*args).first
end
at_xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class]) click to toggle source

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.

# File lib/nokogiri/xml/searchable.rb, line 188
def at_xpath(*args)
  xpath(*args).first
end
css(*rules, [namespace-bindings, custom-pseudo-class]) click to toggle source

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/'})

πŸ’‘ 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)

πŸ’‘ 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

πŸ’‘ 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 β€œH1” in an HTML document, you’ll never find anything. However, β€œH1” might be found in an XML document, where tags names are case-sensitive (e.g., β€œH1” is distinct from β€œh1”).

# File lib/nokogiri/xml/searchable.rb, line 126
def css(*args)
  rules, handler, ns, _ = extract_params(args)

  css_internal(self, rules, handler, ns)
end
xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class]) click to toggle source

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'})

πŸ’‘ 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)
# File lib/nokogiri/xml/searchable.rb, line 174
def xpath(*args)
  paths, handler, ns, binds = extract_params(args)

  xpath_internal(self, paths, handler, ns, binds)
end