angular-docs-cn/public/_includes/_version-dropdown.jade

language = current.path[1]
title = "JavaScript "
filter = /(\.html$)/
replace = /(\.html$)|(^index\.html$)/
version = ''
page = ''

<!-- Replace _ undscores with . dots -->
if current.path[2]
  version = current.path[2].replace(/\_+/gm, ".")

<!-- Replace _ undscores with . dots -->
if current.path[3]
  page = current.path[3]


<!-- VERSION TREE CREATOR MIXIN -->
mixin tree(directory, urlPrefix, name, latest)
  ul
    for val, semvar in directory
      if semvar !== '.git' && semvar !== '_data'
        libVersion = (semvar == "latest") ?  latest : semvar.replace(/\_+/gm, ".")
        li <a href="#{urlPrefix}/#{semvar}/#{page}" md-button>#{name} #{libVersion}</a>


<!-- BUTTON TITLE GENERATION  -->
if language == 'js'
  if version == "latest"
    title = 'Angular 2 for JavaScript'
  else
    title = 'Angular ' + version + ' for JavaScript'


if language == 'dart'
  if version == "latest"
    title = 'Angular 2 for Dart'
  else
    title = 'Angular ' + version + ' for Dart'


<!-- DROPDOWN BUTTON -->
nav.hero-subtitle.text-subhead.dropdown
  button(aria-label="Select a version of Angular" md-button class="dropdown-button" ng-click="toggleVersionMenu($event)") #{title}  <span class="icon icon-arrow-drop-down"></span>
  div(class="overlay ng-hide" ng-click="toggleVersionMenu($event)" ng-show="showMenu")

  <!-- DROPDOWN MENU -->
  div(class="dropdown-menu" ng-class="showMenu ? 'is-visible' : ''")
    mixin tree(public.docs.js, "/docs/js", "Angular 2 for JavaScript")
    mixin tree(public.docs.dart, "/docs/dart", "Angular 2 for Dart")
    ul
      li <a href="https://angularjs.org/" md-button>#{name} Angular 1.X for JavaScript</a>
      li <a href="https://docs.angulardart.org/" md-button>#{name} Angular 1.X for Dart</a>