Module: Nokogiri::XML::Searchable
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Included In:
::Nokogiri::HTML4::Document ,
::Nokogiri::HTML4::DocumentFragment ,
::Nokogiri::HTML5::Document ,
::Nokogiri::HTML5::DocumentFragment ,
::Nokogiri::HTML::Document ,
::Nokogiri::HTML::DocumentFragment ,
Attr ,
AttributeDecl ,
CDATA ,
CharacterData ,
Comment ,
DTD ,
Document ,
DocumentFragment ,
ElementDecl ,
EntityDecl ,
EntityReference ,
Node ,
NodeSet ,
ProcessingInstruction ,
Text ,
::NokogiriHtml5::Document ,
::NokogiriXml::DTD
| |
Defined in: | lib/nokogiri/xml/searchable.rb |
Overview
Constant Summary
-
LOOKS_LIKE_XPATH =
Regular expression used by #search to determine if a query string is
::Nokogiri::CSS
orXPath
%r{^(\./|/|\.\.|\.$)}
Searching via XPath or CSS Queries
-
#%(*args)
Alias for #at.
-
#/(*args)
Alias for #search.
-
#>(selector) → NodeSet)
Search this node’s immediate children using
::Nokogiri::CSS
selectorselector
-
#at(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class])
(also: #%)
Search this object for
paths
, and return only the first result. -
#at_css(*rules, [namespace-bindings, custom-pseudo-class])
Search this object for
::Nokogiri::CSS
rules
, and return only the first match. -
#at_xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class])
Search this node for
XPath
paths
, and return only the first match. -
#css(*rules, [namespace-bindings, custom-pseudo-class])
Search this object for
::Nokogiri::CSS
rules
. - #css_internal(node, rules, handler, ns) private
- #css_rules_to_xpath(rules, ns) private
- #extract_params(params) private Internal use only
-
#search(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class])
(also: #/)
Search this object for
paths
. -
#xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class])
Search this node for
XPath
paths
. - #xpath_impl(node, path, handler, ns, binds) private
- #xpath_internal(node, paths, handler, ns, binds) private
- #xpath_query_from_css_rule(rule, ns) private
Instance Method Details
#%(*args)
Alias for #at.
# File 'lib/nokogiri/xml/searchable.rb', line 78
alias_method :%, :at
#/(*args)
Alias for #search.
# File 'lib/nokogiri/xml/searchable.rb', line 64
alias_method :/, :search
#>(selector) → NodeSet)
Search this node’s immediate children using ::Nokogiri::CSS
selector selector
#at(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class]) Also known as: #%
Search this object for paths
, and return only the first result. paths
must be one or more XPath
or ::Nokogiri::CSS
queries.
See #search for more information.
# File 'lib/nokogiri/xml/searchable.rb', line 74
def at(*args) search(*args).first end
#at_css(*rules, [namespace-bindings, custom-pseudo-class])
Search this object for ::Nokogiri::CSS
rules
, and return only the first match. rules
must be one or more ::Nokogiri::CSS
selectors.
See #css for more information.
# File 'lib/nokogiri/xml/searchable.rb', line 143
def at_css(*args) css(*args).first end
#at_xpath(*paths, [namespace-bindings, variable-bindings, custom-handler-class])
# File 'lib/nokogiri/xml/searchable.rb', line 193
def at_xpath(*args) xpath(*args).first end
#css(*rules, [namespace-bindings, custom-pseudo-class])
Search this object for ::Nokogiri::CSS
rules
. rules
must be one or more ::Nokogiri::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 ::Nokogiri::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 ::Nokogiri::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 ::Nokogiri::CSS
query string is case-sensitive with regards to your document type. ::Nokogiri::HTML
tags will match only lowercase ::Nokogiri::CSS
queries, so if you search for “H1” in an ::Nokogiri::HTML
document, you’ll never find anything. However, “H1” might be found in an ::Nokogiri::XML
document, where tags names are case-sensitive (e.g., “H1” is distinct from “h1”).
# File 'lib/nokogiri/xml/searchable.rb', line 129
def css(*args) rules, handler, ns, _ = extract_params(args) css_internal(self, rules, handler, ns) end
#css_internal(node, rules, handler, ns) (private)
[ GitHub ]# File 'lib/nokogiri/xml/searchable.rb', line 210
def css_internal(node, rules, handler, ns) xpath_internal(node, css_rules_to_xpath(rules, ns), handler, ns, nil) end
#css_rules_to_xpath(rules, ns) (private)
[ GitHub ]# File 'lib/nokogiri/xml/searchable.rb', line 241
def css_rules_to_xpath(rules, ns) rules.map { |rule| xpath_query_from_css_rule(rule, ns) } end
#extract_params(params) (private)
# File 'lib/nokogiri/xml/searchable.rb', line 257
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
#search(*paths, [namespace-bindings, xpath-variable-bindings, custom-handler-class]) Also known as: #/
Search this object for paths
. paths
must be one or more XPath
or ::Nokogiri::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 ::Nokogiri::CSS
pseudo-selectors may also be defined. To define custom functions create a class and implement the function you want to define, which will be in the nokogiri
namespace in XPath
queries.
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[nokogiri:regex(., "\w+")]', 'div.employee:regex("[0-9]+")', handler)
# File 'lib/nokogiri/xml/searchable.rb', line 54
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
#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, which will be in the nokogiri
namespace.
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[nokogiri:regex(., "\w+")]', handler)
# File 'lib/nokogiri/xml/searchable.rb', line 179
def xpath(*args) paths, handler, ns, binds = extract_params(args) xpath_internal(self, paths, handler, ns, binds) end
#xpath_impl(node, path, handler, ns, binds) (private)
[ GitHub ]# File 'lib/nokogiri/xml/searchable.rb', line 229
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
#xpath_internal(node, paths, handler, ns, binds) (private)
[ GitHub ]# File 'lib/nokogiri/xml/searchable.rb', line 214
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
#xpath_query_from_css_rule(rule, ns) (private)
[ GitHub ]# File 'lib/nokogiri/xml/searchable.rb', line 245
def xpath_query_from_css_rule(rule, ns) self.class::IMPLIED_XPATH_CONTEXTS.map do |implied_xpath_context| visitor = Nokogiri::CSS::XPathVisitor.new( builtins: Nokogiri::CSS::XPathVisitor::BuiltinsConfig::OPTIMAL, doctype: document.xpath_doctype, prefix: implied_xpath_context, namespaces: ns, ) CSS.xpath_for(rule.to_s, visitor: visitor) end.join(" | ") end