Module: Nokogiri::XML::Searchable

Included in:
Node, NodeSet
Defined in:
lib/nokogiri/xml/searchable.rb

Overview

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.

Constant Summary

LOOKS_LIKE_XPATH =

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

/^(\.\/|\/|\.\.|\.$)/

Instance Method Summary collapse

Instance Method Details

#at(*args) ⇒ Object Also known as: %

call-seq: search *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.



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# File 'lib/nokogiri/xml/searchable.rb', line 66

def at *args
  search(*args).first
end

#at_css(*args) ⇒ Object

call-seq: 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.



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# File 'lib/nokogiri/xml/searchable.rb', line 117

def at_css *args
  css(*args).first
end

#at_xpath(*args) ⇒ Object

call-seq: 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.



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# File 'lib/nokogiri/xml/searchable.rb', line 185

def at_xpath *args
  xpath(*args).first
end

#css(*args) ⇒ Object

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. 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 current matching NodeSet. Any other arguments are ones that you pass in. For example:

node.css('title:regex("\w+")', Class.new {
  def regex node_set, regex
    node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ }
  end
}.new)

Note that the CSS query string is case-sensitive with regards to your document type. That is, if you're looking for “H1” in an HTML document, you'll never find anything, since HTML tags will match only lowercase CSS queries. However, “H1” might be found in an XML document, where tags names are case-sensitive (e.g., “H1” is distinct from “h1”).



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# File 'lib/nokogiri/xml/searchable.rb', line 104

def css *args
  rules, handler, ns, _ = extract_params(args)

  css_internal self, rules, handler, ns
end

#search(*args) ⇒ Object Also known as: /

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:

node.search('.//title[regex(., "\w+")]', 'div.employee:regex("[0-9]+")'
  Class.new {
    def regex node_set, regex
      node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ }
    end
  }.new
)

See Searchable#xpath and Searchable#css for further usage help.



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# File 'lib/nokogiri/xml/searchable.rb', line 48

def search *args
  paths, handler, ns, binds = extract_params(args)

  xpaths = paths.map(&:to_s).map do |path|
    (path =~ LOOKS_LIKE_XPATH) ? path : xpath_query_from_css_rule(path, ns)
  end.flatten.uniq

  xpath(*(xpaths + [ns, handler, binds].compact))
end

#xpath(*args) ⇒ Object

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:

node.xpath('.//title[regex(., "\w+")]', Class.new {
  def regex node_set, regex
    node_set.find_all { |node| node['some_attribute'] =~ /#{regex}/ }
  end
}.new)


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# File 'lib/nokogiri/xml/searchable.rb', line 151

def xpath *args
  return NodeSet.new(document) unless document

  paths, handler, ns, binds = extract_params(args)

  sets = paths.map do |path|
    ctx = XPathContext.new(self)
    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 if binds

    ctx.evaluate(path, handler)
  end
  return sets.first if sets.length == 1

  NodeSet.new(document) do |combined|
    sets.each do |set|
      set.each do |node|
        combined << node
      end
    end
  end
end