Get Parsed Org Tree (On Lisp by Paul Graham)

This function looks for an Org file in the present working directory, and if it finds one returns a parsed tree using org-element-parse-buffer. It returns ‘nil’ if there is no Org file or if the found file is not in org-mode.

(defun get-parsed-org-tree (&optional org-dir)
  "This function takes an optional directory name, changes to
that directory if given, otherwise uses the pwd, and finds an Org
file and returns its parsed tree, or nil if none found."
  (when org-dir
      (cd (file-name-as-directory org-dir)))
  (let ((buf (car-safe (find-file-noselect "*.org" nil nil t))))
    (if buf
        (with-current-buffer buf (org-element-parse-buffer))
      nil)))

A.3.1 Get Parsed Org Tree