Class: REXML::XPath
Relationships & Source Files | |
Super Chains via Extension / Inclusion / Inheritance | |
Instance Chain:
self,
Functions
|
|
Inherits: | Object |
Defined in: | lib/rexml/xpath.rb |
Overview
Wrapper class. Use this class to access the XPath
functions.
Constant Summary
-
EMPTY_HASH =
A base Hash object, supposing to be used when initializing a default empty namespaces set, but is currently unused. TODO: either set the namespaces=EMPTY_HASH, or deprecate this.
{}
Functions - Included
Class Method Summary
-
.each(element, path = nil, namespaces = nil, variables = {}, &block)
Iterates over nodes that match the given path, calling the supplied block with the match.
-
.first(element, path = nil, namespaces = nil, variables = {})
Finds and returns the first node that matches the supplied xpath.
-
.match(element, path = nil, namespaces = nil, variables = {})
Returns an array of nodes matching a given
XPath
.
Class Method Details
.each(element, path = nil, namespaces = nil, variables = {}, &block)
Iterates over nodes that match the given path, calling the supplied block with the match.
- element
-
The context element
- path
-
The xpath to search for. If not supplied or nil, defaults to '*'
- namespaces
-
If supplied, a Hash which defines a namespace mapping
- variables
-
If supplied, a Hash which maps $variables in the query to values. This can be used to avoid XPath injection attacks or to automatically handle escaping string values.
XPath.each( node ) { |el| ... }
XPath.each( node, '/*[@attr='v']' ) { |el| ... }
XPath.each( node, 'ancestor::x' ) { |el| ... }
XPath.each( node, '/book/publisher/text()=$publisher', {}, {"publisher"=>"O'Reilly"}) \
{|el| ... }
# File 'lib/rexml/xpath.rb', line 60
def XPath::each element, path=nil, namespaces=nil, variables={}, &block raise "The namespaces argument, if supplied, must be a hash object." unless namespaces.nil? or namespaces.kind_of?(Hash) raise "The variables argument, if supplied, must be a hash object." unless variables.kind_of?(Hash) parser = XPathParser.new parser.namespaces = namespaces parser.variables = variables path = "*" unless path element = [element] unless element.kind_of? Array parser.parse(path, element).each( &block ) end
.first(element, path = nil, namespaces = nil, variables = {})
Finds and returns the first node that matches the supplied xpath.
- element
-
The context element
- path
-
The xpath to search for. If not supplied or nil, returns the first node matching '*'.
- namespaces
-
If supplied, a Hash which defines a namespace mapping.
- variables
-
If supplied, a Hash which maps $variables in the query to values. This can be used to avoid XPath injection attacks or to automatically handle escaping string values.
XPath.first( node )
XPath.first( doc, "//b"} )
XPath.first( node, "a/x:b", { "x"=>"http://doofus" } )
XPath.first( node, '/book/publisher/text()=$publisher', {}, {"publisher"=>"O'Reilly"})
# File 'lib/rexml/xpath.rb', line 31
def XPath::first element, path=nil, namespaces=nil, variables={} raise "The namespaces argument, if supplied, must be a hash object." unless namespaces.nil? or namespaces.kind_of?(Hash) raise "The variables argument, if supplied, must be a hash object." unless variables.kind_of?(Hash) parser = XPathParser.new parser.namespaces = namespaces parser.variables = variables path = "*" unless path element = [element] unless element.kind_of? Array parser.parse(path, element).flatten[0] end
.match(element, path = nil, namespaces = nil, variables = {})
Returns an array of nodes matching a given XPath
.
# File 'lib/rexml/xpath.rb', line 72
def XPath::match element, path=nil, namespaces=nil, variables={} parser = XPathParser.new parser.namespaces = namespaces parser.variables = variables path = "*" unless path element = [element] unless element.kind_of? Array parser.parse(path,element) end