#+TITLE: org-mode根据不同条件tangle不同代码块
#+AUTHOR: lujun9972
#+TAGS: Emacs之怒
#+DATE: [2019-03-08 五 16:57]
#+LANGUAGE:  zh-CN
#+STARTUP:  inlineimages
#+OPTIONS:  H:6 num:nil toc:t \n:nil ::t |:t ^:nil -:nil f:t *:t <:nil

原来org-mode中代码块的参数可以是一段elisp代码，这个特性可以让我们动态tangle不同代码块，像这样(代码摘自https://eschulte.github.io/org-scraps/scraps/2010-08-31-conditional-tangling.html):

#+BEGIN_SRC org
  ,* conditional tangling
    :PROPERTIES:
    :DATE:     2010-08-31
    :END:
    ,#+begin_src emacs-lisp :results silent
      (setq tangle-tag "right")
    ,#+end_src

  ,** first subheading                                                    :left:
     :PROPERTIES:
     :DATE:     2010-08-31
     :END:
     ,#+begin_src R :tangle (and (equal (car (org-get-tags-at (point))) tangle-tag) "yes")
   "first"
     ,#+end_src

  ,** second subheading                                                  :right:
     :PROPERTIES:
     :DATE:     2010-08-31
     :END:
     ,#+begin_src R :tangle (and (equal (car (org-get-tags-at (point))) tangle-tag) "yes")
   "second"
     ,#+end_src
#+END_SRC