discourse/lib/es6_module_transpiler/tilt/es6_module_transpiler_templ...

128 lines
3.5 KiB
Ruby

require 'execjs'
module Tilt
class ES6ModuleTranspilerTemplate < Tilt::Template
self.default_mime_type = 'application/javascript'
@mutex = Mutex.new
@ctx_init = Mutex.new
def prepare
# intentionally left empty
# Tilt requires this method to be defined
end
def self.create_new_context
ctx = V8::Context.new(timeout: 5000)
ctx.eval("module = {}; exports = {};");
ctx.load("#{Rails.root}/lib/es6_module_transpiler/support/es6-module-transpiler.js")
ctx
end
def self.v8
return @ctx if @ctx
# ensure we only init one of these
@ctx_init.synchronize do
return @ctx if @ctx
@ctx = create_new_context
end
@ctx
end
class JavaScriptError < StandardError
attr_accessor :message, :backtrace
def initialize(message, backtrace)
@message = message
@backtrace = backtrace
end
end
def self.protect
rval = nil
@mutex.synchronize do
begin
rval = yield
# This may seem a bit odd, but we don't want to leak out
# objects that require locks on the v8 vm, to get a backtrace
# you need a lock, if this happens in the wrong spot you can
# deadlock a process
rescue V8::Error => e
raise JavaScriptError.new(e.message, e.backtrace)
end
end
rval
end
def evaluate(scope, locals, &block)
return @output if @output
klass = self.class
klass.protect do
@output = klass.v8.eval(generate_source(scope))
end
# For backwards compatibility with plugins, for now export the Global format too.
# We should eventually have an upgrade system for plugins to use ES6 or some other
# resolve based API.
if ENV['DISCOURSE_NO_CONSTANTS'].nil? && scope.logical_path =~ /discourse\/(controllers|components|views)\/(.*)/
type = Regexp.last_match[1]
file_name = Regexp.last_match[2].gsub(/[\-\/]/, '_')
class_name = file_name.classify
# Rails removes pluralization when calling classify
if file_name.end_with?('s') && (!class_name.end_with?('s'))
class_name << "s"
end
require_name = module_name(scope.root_path, scope.logical_path)
@output << "\n\nDiscourse.#{class_name}#{type.classify} = require('#{require_name}').default"
end
@output
end
private
def generate_source(scope)
"new module.exports.Compiler(#{::JSON.generate(data, quirks_mode: true)}, '#{module_name(scope.root_path, scope.logical_path)}', #{compiler_options}).#{compiler_method}()"
end
def module_name(root_path, logical_path)
path = nil
root_base = File.basename(Rails.root)
# If the resource is a plugin, use the plugin name as a prefix
if root_path =~ /(.*\/#{root_base}\/plugins\/[^\/]+)\//
plugin_path = "#{Regexp.last_match[1]}/plugin.rb"
plugin = Discourse.plugins.find {|p| p.path == plugin_path }
path = "discourse/plugins/#{plugin.name}/#{logical_path.sub(/javascripts\//, '')}" if plugin
end
path ||= logical_path
if ES6ModuleTranspiler.transform
path = ES6ModuleTranspiler.transform.call(path)
end
path
end
def compiler_method
type = {
amd: 'AMD',
cjs: 'CJS',
globals: 'Globals'
}[ES6ModuleTranspiler.compile_to.to_sym]
"to#{type}"
end
def compiler_options
::JSON.generate(ES6ModuleTranspiler.compiler_options, quirks_mode: true)
end
end
end