org-tag-eldoc-database.el

   1 ;;; org-tag-eldoc-database.el --- org-tag-eldoc database storage -*- lexical-binding: t; -*-
   2 ;; -*- coding: utf-8 -*-
   3
   4 ;; Copyright (C) 2024-2025 Christopher M. Miles, all rights reserved.
   5
   6 ;;; Commentary:
   7
   8
   9
  10 ;;; Code:
  11 \f
  12 (require 'sqlite nil t)
  13
  14
  15 (defcustom org-tag-eldoc-database-file
  16   (expand-file-name ".org-tag-eldoc-database.db" user-emacs-directory)
  17   "The location of org-tag-eldoc SQLite3 database."
  18   :type 'string
  19   :safe #'stringp
  20   :group 'org-tags)
  21
  22 (defmacro org-tag-eldoc-database--execute-with-db (&rest body)
  23   "A macro for execute BODY with database."
  24   `(if (sqlite-available-p)
  25        (let ((db (sqlite-open org-tag-eldoc-database-file)))
  26          (prog1 db
  27            ,@body
  28            (sqlite-close db)))
  29      (error (format "[org-tag-eldoc] Error: database backend SQLite support of Emacs not available!"))))
  30
  31 ;;; TEST: expand the macro
  32 ;; (macroexpand-all
  33 ;;  '(org-tag-eldoc-database--execute-with-db
  34 ;;    (sqlite-select db "SELECT 1+1;")
  35 ;;    (sqlite-execute db "SELECT 1+1;")))
  36
  37 ;;;###autoload
  38 (defun org-tag-eldoc-database--initlize ()
  39   "Initialize the default SQLite3 database file `org-tag-eldoc-database-file'."
  40   ;; Create the empty SQLite3 database file.
  41   (unless (file-exists-p org-tag-eldoc-database-file)
  42     (shell-command
  43      (format "sqlite3 %s \"VACUUM\";" org-tag-eldoc-database-file))
  44     (org-tag-eldoc-database--execute-with-db
  45      (sqlite-execute db (format "CREATE TABLE 'org-tag-eldoc' (tag VARCHAR, explanation TEXT);")))))
  46
  47 ;;;###autoload
  48 (org-tag-eldoc-database--initlize)
  49
  50 (defun org-tag-eldoc-database-query (tag)
  51   "Query TAG for explanation in database."
  52   (org-tag-eldoc-database--execute-with-db
  53    (setq org-tag-eldoc--explanation
  54          (caar
  55           (sqlite-select db (format "SELECT explanation from 'org-tag-eldoc' WHERE tag = '%s';" tag))))))
  56
  57 (defun org-tag-eldoc-database-save (tag explanation)
  58   "Save TAG and EXPLANATION into database."
  59   (org-tag-eldoc-database--execute-with-db
  60    (sqlite-execute db (format "INSERT INTO 'org-tag-eldoc' (tag, explanation) VALUES ('%s', '%s');" tag explanation)))
  61   ;; Still return the `explanation' after save to database.
  62   explanation)
  63
  64 \f
  65
  66 (provide 'org-tag-eldoc-database)
  67
  68 ;;; org-tag-eldoc-database.el ends here