Orbit/vendor/plugins/radius/lib/radius/parser.rb

80 lines
2.6 KiB
Ruby

module Radius
#
# The Radius parser. Initialize a parser with a Context object that
# defines how tags should be expanded. See the QUICKSTART[link:files/QUICKSTART.html]
# for a detailed explaination of its usage.
#
class Parser
# The Context object used to expand template tags.
attr_accessor :context
# The string that prefixes all tags that are expanded by a parser
# (the part in the tag name before the first colon).
attr_accessor :tag_prefix
# The class that performs tokenization of the input string
attr_accessor :scanner
# Creates a new parser object initialized with a Context.
def initialize(context = Context.new, options = {})
if context.kind_of?(Hash) and options.empty?
options, context = context, (context[:context] || context['context'])
end
options = Utility.symbolize_keys(options)
self.context = context ? context.dup : Context.new
self.tag_prefix = options[:tag_prefix] || 'radius'
self.scanner = options[:scanner] || default_scanner
end
# Parses string for tags, expands them, and returns the result.
def parse(string)
@stack = [ ParseContainerTag.new { |t| Utility.array_to_s(t.contents) } ]
tokenize(string)
stack_up
@stack.last.to_s
end
protected
# Convert the string into a list of text blocks and scanners (tokens)
def tokenize(string)
@tokens = scanner.operate(tag_prefix, string)
end
def stack_up
@tokens.each do |t|
if t.is_a? String
@stack.last.contents << t
next
end
case t[:flavor]
when :open
@stack.push(ParseContainerTag.new(t[:name], t[:attrs]))
when :self
@stack.last.contents << ParseTag.new {@context.render_tag(t[:name], t[:attrs])}
when :close
popped = @stack.pop
raise WrongEndTagError.new(popped.name, t[:name], @stack) if popped.name != t[:name]
popped.on_parse { |b| @context.render_tag(popped.name, popped.attributes) { Utility.array_to_s(b.contents) } }
@stack.last.contents << popped
when :tasteless
raise TastelessTagError.new(t, @stack)
else
raise UndefinedFlavorError.new(t, @stack)
end
end
raise MissingEndTagError.new(@stack.last.name, @stack) if @stack.length != 1
end
def default_scanner
if RUBY_PLATFORM == 'java'
require 'java'
require 'radius/parser/java_scanner.jar'
::Radius.send(:include_package, 'radius.parser')
Radius::JavaScanner.new(JRuby.runtime)
else
Radius::Scanner.new
end
end
end
end