diff options
Diffstat (limited to 'actionpack/lib/action_dispatch/journey/visitors.rb')
-rw-r--r-- | actionpack/lib/action_dispatch/journey/visitors.rb | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/visitors.rb b/actionpack/lib/action_dispatch/journey/visitors.rb new file mode 100644 index 0000000000..52b4c8b489 --- /dev/null +++ b/actionpack/lib/action_dispatch/journey/visitors.rb @@ -0,0 +1,221 @@ +# encoding: utf-8 + +module ActionDispatch + module Journey # :nodoc: + class Format + ESCAPE_PATH = ->(value) { Router::Utils.escape_path(value) } + ESCAPE_SEGMENT = ->(value) { Router::Utils.escape_segment(value) } + + class Parameter < Struct.new(:name, :escaper) + def escape(value); escaper.call value; end + end + + def self.required_path(symbol) + Parameter.new symbol, ESCAPE_PATH + end + + def self.required_segment(symbol) + Parameter.new symbol, ESCAPE_SEGMENT + end + + def initialize(parts) + @parts = parts + @children = [] + @parameters = [] + + parts.each_with_index do |object,i| + case object + when Journey::Format + @children << i + when Parameter + @parameters << i + end + end + end + + def evaluate(hash) + parts = @parts.dup + + @parameters.each do |index| + param = parts[index] + value = hash[param.name] + return ''.freeze unless value + parts[index] = param.escape value + end + + @children.each { |index| parts[index] = parts[index].evaluate(hash) } + + parts.join + end + end + + module Visitors # :nodoc: + class Visitor # :nodoc: + DISPATCH_CACHE = {} + + def accept(node) + visit(node) + end + + private + + def visit node + send(DISPATCH_CACHE[node.type], node) + end + + def binary(node) + visit(node.left) + visit(node.right) + end + def visit_CAT(n); binary(n); end + + def nary(node) + node.children.each { |c| visit(c) } + end + def visit_OR(n); nary(n); end + + def unary(node) + visit(node.left) + end + def visit_GROUP(n); unary(n); end + def visit_STAR(n); unary(n); end + + def terminal(node); end + def visit_LITERAL(n); terminal(n); end + def visit_SYMBOL(n); terminal(n); end + def visit_SLASH(n); terminal(n); end + def visit_DOT(n); terminal(n); end + + private_instance_methods(false).each do |pim| + next unless pim =~ /^visit_(.*)$/ + DISPATCH_CACHE[$1.to_sym] = pim + end + end + + class FormatBuilder < Visitor # :nodoc: + def accept(node); Journey::Format.new(super); end + def terminal(node); [node.left]; end + + def binary(node) + visit(node.left) + visit(node.right) + end + + def visit_GROUP(n); [Journey::Format.new(unary(n))]; end + + def visit_STAR(n) + [Journey::Format.required_path(n.left.to_sym)] + end + + def visit_SYMBOL(n) + symbol = n.to_sym + if symbol == :controller + [Journey::Format.required_path(symbol)] + else + [Journey::Format.required_segment(symbol)] + end + end + end + + # Loop through the requirements AST + class Each < Visitor # :nodoc: + attr_reader :block + + def initialize(block) + @block = block + end + + def visit(node) + block.call(node) + super + end + end + + class String < Visitor # :nodoc: + private + + def binary(node) + [visit(node.left), visit(node.right)].join + end + + def nary(node) + node.children.map { |c| visit(c) }.join '|' + end + + def terminal(node) + node.left + end + + def visit_GROUP(node) + "(#{visit(node.left)})" + end + end + + class Dot < Visitor # :nodoc: + def initialize + @nodes = [] + @edges = [] + end + + def accept(node) + super + <<-eodot + digraph parse_tree { + size="8,5" + node [shape = none]; + edge [dir = none]; + #{@nodes.join "\n"} + #{@edges.join("\n")} + } + eodot + end + + private + + def binary(node) + node.children.each do |c| + @edges << "#{node.object_id} -> #{c.object_id};" + end + super + end + + def nary(node) + node.children.each do |c| + @edges << "#{node.object_id} -> #{c.object_id};" + end + super + end + + def unary(node) + @edges << "#{node.object_id} -> #{node.left.object_id};" + super + end + + def visit_GROUP(node) + @nodes << "#{node.object_id} [label=\"()\"];" + super + end + + def visit_CAT(node) + @nodes << "#{node.object_id} [label=\"○\"];" + super + end + + def visit_STAR(node) + @nodes << "#{node.object_id} [label=\"*\"];" + super + end + + def visit_OR(node) + @nodes << "#{node.object_id} [label=\"|\"];" + super + end + + def terminal(node) + value = node.left + + @nodes << "#{node.object_id} [label=\"#{value}\"];" + end + end + end + end +end |