class REXML::Parsers::XPathParser
You don’t want to use this class. Really. Use XPath
, which is a wrapper for this class. Believe me. You don’t want to poke around in here. There is strange, dark magic at work in this code. Beware. Go back! Go back while you still can!
Constants
- AXIS
-
| Step | (AXIS_NAME '::' | '@' | '') AxisSpecifier NodeTest Predicate | '.' | '..' AbbreviatedStep | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
- LITERAL
- LOCAL_NAME_WILDCARD
- NODE_TYPE
- NT
- NUMBER
- PI
- PREFIX_WILDCARD
Returns a 1-1 map of the nodeset The contents of the resulting array are either: true/false, if a positive match String, if a name match
| ('*' | NCNAME ':' '*' | QNAME) NameTest | '*' ':' NCNAME NameTest since XPath 2.0 | NODE_TYPE '(' ')' NodeType | PI '(' LITERAL ')' PI | '[' expr ']' Predicate
- QNAME
- VARIABLE_REFERENCE
|
VARIABLE_REFERENCE
| ‘(’ expr ‘)’ |LITERAL
|NUMBER
|FunctionCall
Public Instance Methods
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 42 def abbreviate(path_or_parsed) if path_or_parsed.kind_of?(String) parsed = parse(path_or_parsed) else parsed = path_or_parsed end components = [] component = nil while parsed.size > 0 op = parsed.shift case op when :node component << "node()" when :attribute component = "@" components << component when :child component = "" components << component when :descendant_or_self next_op = parsed[0] if next_op == :node parsed.shift component = "" components << component else component = "descendant-or-self::" components << component end when :self next_op = parsed[0] if next_op == :node parsed.shift components << "." else component = "self::" components << component end when :parent next_op = parsed[0] if next_op == :node parsed.shift components << ".." else component = "parent::" components << component end when :any component << "*" when :text component << "text()" when :following, :following_sibling, :ancestor, :ancestor_or_self, :descendant, :namespace, :preceding, :preceding_sibling component = op.to_s.tr("_", "-") << "::" components << component when :qname prefix = parsed.shift name = parsed.shift component << prefix+":" if prefix.size > 0 component << name when :predicate component << '[' component << predicate_to_path(parsed.shift) {|x| abbreviate(x)} component << ']' when :document components << "" when :function component << parsed.shift component << "( " component << predicate_to_path(parsed.shift[0]) {|x| abbreviate(x)} component << " )" when :literal component << quote_literal(parsed.shift) else component << "UNKNOWN(" component << op.inspect component << ")" end end case components when [""] "/" when ["", ""] "//" else components.join("/") end end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 132 def expand(path_or_parsed) if path_or_parsed.kind_of?(String) parsed = parse(path_or_parsed) else parsed = path_or_parsed end path = "" document = false while parsed.size > 0 op = parsed.shift case op when :node path << "node()" when :attribute, :child, :following, :following_sibling, :ancestor, :ancestor_or_self, :descendant, :descendant_or_self, :namespace, :preceding, :preceding_sibling, :self, :parent path << "/" unless path.size == 0 path << op.to_s.tr("_", "-") path << "::" when :any path << "*" when :qname prefix = parsed.shift name = parsed.shift path << prefix+":" if prefix.size > 0 path << name when :predicate path << '[' path << predicate_to_path( parsed.shift ) { |x| expand(x) } path << ']' when :document document = true else path << "UNKNOWN(" path << op.inspect path << ")" end end path = "/"+path if document path end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 16 def namespaces=( namespaces ) Functions::namespace_context = namespaces @namespaces = namespaces end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 21 def parse path path = path.dup path.gsub!(/([\(\[])\s+/, '\1') # Strip ignorable spaces path.gsub!( /\s+([\]\)])/, '\1') parsed = [] rest = OrExpr(path, parsed) if rest unless rest.strip.empty? raise ParseException.new("Garbage component exists at the end: " + "<#{rest}>: <#{path}>") end end parsed end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 36 def predicate path parsed = [] Predicate( "[#{path}]", parsed ) parsed end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 174 def predicate_to_path(parsed, &block) path = "" case parsed[0] when :and, :or, :mult, :plus, :minus, :neq, :eq, :lt, :gt, :lteq, :gteq, :div, :mod, :union op = parsed.shift case op when :eq op = "=" when :lt op = "<" when :gt op = ">" when :lteq op = "<=" when :gteq op = ">=" when :neq op = "!=" when :union op = "|" end left = predicate_to_path( parsed.shift, &block ) right = predicate_to_path( parsed.shift, &block ) path << left path << " " path << op.to_s path << " " path << right when :function parsed.shift name = parsed.shift path << name path << "(" parsed.shift.each_with_index do |argument, i| path << ", " if i > 0 path << predicate_to_path(argument, &block) end path << ")" when :literal parsed.shift path << quote_literal(parsed.shift) else path << yield( parsed ) end return path.squeeze(" ") end
Private Instance Methods
| AdditiveExpr
(‘+’ | ‘-’) MultiplicativeExpr
| MultiplicativeExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 505 def AdditiveExpr path, parsed n = [] rest = MultiplicativeExpr( path, n ) if rest != path while rest =~ /^\s*(\+|-)\s*/ if $1[0] == ?+ n = [ :plus, n, [] ] else n = [ :minus, n, [] ] end rest = MultiplicativeExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
| AndExpr
S ‘and’ S EqualityExpr
| EqualityExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 438 def AndExpr path, parsed n = [] rest = EqualityExpr( path, n ) if rest != path while rest =~ /^\s*( and )/ n = [ :and, n, [] ] rest = EqualityExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
| EqualityExpr
(‘=’ | ‘!=’) RelationalExpr
| RelationalExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 457 def EqualityExpr path, parsed n = [] rest = RelationalExpr( path, n ) if rest != path while rest =~ /^\s*(!?=)\s*/ if $1[0] == ?! n = [ :neq, n, [] ] else n = [ :eq, n, [] ] end rest = RelationalExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
| FilterExpr
Predicate
| PrimaryExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 608 def FilterExpr path, parsed n = [] path_before_primary_expr = path path = PrimaryExpr(path, n) return path_before_primary_expr if path == path_before_primary_expr path = Predicate(path, n) parsed.concat(n) path end
| FUNCTION_NAME ‘(’ ( expr ( ‘,’ expr )* )? ‘)’
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 663 def FunctionCall rest, parsed path, arguments = parse_args(rest) argset = [] for argument in arguments args = [] OrExpr( argument, args ) argset << args end parsed << argset path end
| RelativeLocationPath | '/' RelativeLocationPath? | '//' RelativeLocationPath
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 243 def LocationPath path, parsed path = path.lstrip if path[0] == ?/ parsed << :document if path[1] == ?/ parsed << :descendant_or_self parsed << :node path = path[2..-1] else path = path[1..-1] end end return RelativeLocationPath( path, parsed ) if path.size > 0 end
| MultiplicativeExpr
(‘*’ | S (‘div’ | ‘mod’) S) UnaryExpr
| UnaryExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 528 def MultiplicativeExpr path, parsed n = [] rest = UnaryExpr( path, n ) if rest != path while rest =~ /^\s*(\*| div | mod )\s*/ if $1[0] == ?* n = [ :mult, n, [] ] elsif $1.include?( "div" ) n = [ :div, n, [] ] else n = [ :mod, n, [] ] end rest = UnaryExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 343 def NodeTest path, parsed original_path = path path = path.lstrip case path when PREFIX_WILDCARD prefix = nil name = $1 path = $' parsed << :qname parsed << prefix parsed << name when /^\*/ path = $' parsed << :any when NODE_TYPE type = $1 path = $' parsed << type.tr('-', '_').intern when PI path = $' literal = nil if path =~ /^\s*\)/ path = $' else path =~ LITERAL literal = $1 path = $' raise ParseException.new("Missing ')' after processing instruction") if path[0] != ?) path = path[1..-1] end parsed << :processing_instruction parsed << (literal || '') when LOCAL_NAME_WILDCARD prefix = $1 path = $' parsed << :namespace parsed << prefix when QNAME prefix = $1 name = $2 path = $' prefix = "" unless prefix parsed << :qname parsed << prefix parsed << name else path = original_path end return path end
| OrExpr
S ‘or’ S AndExpr
| AndExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 419 def OrExpr path, parsed n = [] rest = AndExpr( path, n ) if rest != path while rest =~ /^\s*( or )/ n = [ :or, n, [] ] rest = AndExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
| LocationPath
| FilterExpr
(‘/’ | ‘//’) RelativeLocationPath
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 590 def PathExpr path, parsed path = path.lstrip n = [] rest = FilterExpr( path, n ) if rest != path if rest and rest[0] == ?/ rest = RelativeLocationPath(rest, n) parsed.concat(n) return rest end end rest = LocationPath(rest, n) if rest =~ /\A[\/\.\@\[\w*]/ parsed.concat(n) return rest end
Filters the supplied nodeset on the predicate(s)
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 395 def Predicate path, parsed original_path = path path = path.lstrip return original_path unless path[0] == ?[ predicates = [] while path[0] == ?[ path, expr = get_group(path) predicates << expr[1..-2] if expr end predicates.each{ |pred| preds = [] parsed << :predicate parsed << preds OrExpr(pred, preds) } path end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 626 def PrimaryExpr path, parsed case path when VARIABLE_REFERENCE varname = $1 path = $' parsed << :variable parsed << varname #arry << @variables[ varname ] when /^(\w[-\w]*)(?:\()/ fname = $1 tmp = $' return path if fname =~ NT path = tmp parsed << :function parsed << fname path = FunctionCall(path, parsed) when NUMBER varname = $1.nil? ? $2 : $1 path = $' parsed << :literal parsed << (varname.include?('.') ? varname.to_f : varname.to_i) when LITERAL varname = $1.nil? ? $2 : $1 path = $' parsed << :literal parsed << varname when /^\(/ #/ path, contents = get_group(path) contents = contents[1..-2] n = [] OrExpr( contents, n ) parsed.concat(n) end path end
| RelationalExpr
(‘<’ | ‘>’ | ‘<=’ | ‘>=’) AdditiveExpr
| AdditiveExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 480 def RelationalExpr path, parsed n = [] rest = AdditiveExpr( path, n ) if rest != path while rest =~ /^\s*([<>]=?)\s*/ if $1[0] == ?< sym = "lt" else sym = "gt" end sym << "eq" if $1[-1] == ?= n = [ sym.intern, n, [] ] rest = AdditiveExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace(n) elsif n.size > 0 parsed << n end rest end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 267 def RelativeLocationPath path, parsed loop do original_path = path path = path.lstrip return original_path if path.empty? # (axis or @ or <child::>) nodetest predicate > # OR > / Step # (. or ..) > if path[0] == ?. if path[1] == ?. parsed << :parent parsed << :node path = path[2..-1] else parsed << :self parsed << :node path = path[1..-1] end else path_before_axis_specifier = path parsed_not_abberviated = [] if path[0] == ?@ parsed_not_abberviated << :attribute path = path[1..-1] # Goto Nodetest elsif path =~ AXIS parsed_not_abberviated << $1.tr('-','_').intern path = $' # Goto Nodetest else parsed_not_abberviated << :child end path_before_node_test = path path = NodeTest(path, parsed_not_abberviated) if path == path_before_node_test return path_before_axis_specifier end path = Predicate(path, parsed_not_abberviated) parsed.concat(parsed_not_abberviated) end original_path = path path = path.lstrip return original_path if path.empty? return original_path if path[0] != ?/ if path[1] == ?/ parsed << :descendant_or_self parsed << :node path = path[2..-1] else path = path[1..-1] end end end
| UnionExpr
‘|’ PathExpr
| PathExpr
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 571 def UnionExpr path, parsed n = [] rest = PathExpr( path, n ) if rest != path while rest =~ /^\s*(\|)\s*/ n = [ :union, n, [] ] rest = PathExpr( $', n[-1] ) end end if parsed.size == 0 and n.size != 0 parsed.replace( n ) elsif n.size > 0 parsed << n end rest end
get_group
( ‘[foo]bar’ ) -> [‘bar’, ‘[foo]’]
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 676 def get_group string ind = 0 depth = 0 st = string[0,1] en = (st == "(" ? ")" : "]") begin case string[ind,1] when st depth += 1 when en depth -= 1 end ind += 1 end while depth > 0 and ind < string.length return nil unless depth==0 [string[ind..-1], string[0..ind-1]] end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 694 def parse_args( string ) arguments = [] ind = 0 inquot = false inapos = false depth = 1 begin case string[ind] when ?" inquot = !inquot unless inapos when ?' inapos = !inapos unless inquot else unless inquot or inapos case string[ind] when ?( depth += 1 if depth == 1 string = string[1..-1] ind -= 1 end when ?) depth -= 1 if depth == 0 s = string[0,ind].strip arguments << s unless s == "" string = string[ind+1..-1] end when ?, if depth == 1 s = string[0,ind].strip arguments << s unless s == "" string = string[ind+1..-1] ind = -1 end end end end ind += 1 end while depth > 0 and ind < string.length return nil unless depth==0 [string,arguments] end
# File rexml-3.2.8/lib/rexml/parsers/xpathparser.rb, line 224 def quote_literal( literal ) case literal when String # XPath 1.0 does not support escape characters. # Assumes literal does not contain both single and double quotes. if literal.include?("'") "\"#{literal}\"" else "'#{literal}'" end else literal.inspect end end