lisp/ob-sqlite.el

   1 ;;; ob-sqlite.el --- org-babel functions for sqlite database interaction
   2
   3 ;; Copyright (C) 2010-2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Eric Schulte
   6 ;; Keywords: literate programming, reproducible research
   7 ;; Homepage: http://orgmode.org
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Org-Babel support for evaluating sqlite source code.
  27
  28 ;;; Code:
  29 (require 'ob)
  30 (require 'ob-eval)
  31 (require 'ob-ref)
  32
  33 (declare-function org-fill-template "org" (template alist))
  34 (declare-function org-table-convert-region "org-table"
  35                   (beg0 end0 &optional separator))
  36 (declare-function orgtbl-to-csv "org-table" (table params))
  37 (declare-function org-table-to-lisp "org-table" (&optional txt))
  38
  39 (defvar org-babel-default-header-args:sqlite '())
  40
  41 (defvar org-babel-header-args:sqlite
  42   '((db        . :any)
  43     (header    . :any)
  44     (echo      . :any)
  45     (bail      . :any)
  46     (csv       . :any)
  47     (column    . :any)
  48     (html      . :any)
  49     (line      . :any)
  50     (list      . :any)
  51     (separator . :any)
  52     (nullvalue . :any))
  53   "Sqlite specific header args.")
  54
  55 (defun org-babel-expand-body:sqlite (body params)
  56   "Expand BODY according to the values of PARAMS."
  57   (org-babel-sqlite-expand-vars
  58    body (mapcar #'cdr (org-babel-get-header params :var))))
  59
  60 (defvar org-babel-sqlite3-command "sqlite3")
  61
  62 (defun org-babel-execute:sqlite (body params)
  63   "Execute a block of Sqlite code with Babel.
  64 This function is called by `org-babel-execute-src-block'."
  65   (let ((result-params (split-string (or (cdr (assoc :results params)) "")))
  66         (db (cdr (assoc :db params)))
  67         (separator (cdr (assoc :separator params)))
  68         (nullvalue (cdr (assoc :nullvalue params)))
  69         (headers-p (equal "yes" (cdr (assoc :colnames params))))
  70         (others (delq nil (mapcar
  71                            (lambda (arg) (car (assoc arg params)))
  72                            (list :header :echo :bail :column
  73                                  :csv :html :line :list))))
  74         exit-code)
  75     (unless db (error "ob-sqlite: can't evaluate without a database"))
  76     (with-temp-buffer
  77       (insert
  78        (org-babel-eval
  79         (org-fill-template
  80          "%cmd %header %separator %nullvalue %others %csv %db "
  81          (list
  82           (cons "cmd" org-babel-sqlite3-command)
  83           (cons "header" (if headers-p "-header" "-noheader"))
  84           (cons "separator"
  85                 (if separator (format "-separator %s" separator) ""))
  86           (cons "nullvalue"
  87                 (if nullvalue (format "-nullvalue %s" nullvalue) ""))
  88           (cons "others"
  89                 (mapconcat
  90                  (lambda (arg) (format "-%s" (substring (symbol-name arg) 1)))
  91                  others " "))
  92           ;; for easy table parsing, default header type should be -csv
  93           (cons "csv" (if (or (member :csv others) (member :column others)
  94                               (member :line others) (member :list others)
  95                               (member :html others) separator)
  96                           ""
  97                         "-csv"))
  98           (cons "db " db)))
  99         ;; body of the code block
 100         (org-babel-expand-body:sqlite body params)))
 101       (org-babel-result-cond result-params
 102         (buffer-string)
 103         (if (equal (point-min) (point-max))
 104             ""
 105           (org-table-convert-region (point-min) (point-max)
 106                                     (if (or (member :csv others)
 107                                             (member :column others)
 108                                             (member :line others)
 109                                             (member :list others)
 110                                             (member :html others) separator)
 111                                         nil
 112                                       '(4)))
 113           (org-babel-sqlite-table-or-scalar
 114            (org-babel-sqlite-offset-colnames
 115             (org-table-to-lisp) headers-p)))))))
 116
 117 (defun org-babel-sqlite-expand-vars (body vars)
 118   "Expand the variables held in VARS in BODY."
 119   (mapc
 120    (lambda (pair)
 121      (setq body
 122            (replace-regexp-in-string
 123             (format "\$%s" (car pair))
 124             ((lambda (val)
 125                (if (listp val)
 126                    ((lambda (data-file)
 127                       (with-temp-file data-file
 128                         (insert (orgtbl-to-csv
 129                                  val '(:fmt (lambda (el) (if (stringp el)
 130                                                              el
 131                                                            (format "%S" el)))))))
 132                       data-file)
 133                     (org-babel-temp-file "sqlite-data-"))
 134                  (if (stringp val) val (format "%S" val))))
 135              (cdr pair))
 136             body)))
 137    vars)
 138   body)
 139
 140 (defun org-babel-sqlite-table-or-scalar (result)
 141   "If RESULT looks like a trivial table, then unwrap it."
 142   (if (and (equal 1 (length result))
 143            (equal 1 (length (car result))))
 144       (org-babel-read (caar result))
 145     (mapcar (lambda (row)
 146               (if (equal 'hline row)
 147                   'hline
 148                 (mapcar #'org-babel-read row))) result)))
 149
 150 (defun org-babel-sqlite-offset-colnames (table headers-p)
 151   "If HEADERS-P is non-nil then offset the first row as column names."
 152   (if headers-p
 153       (cons (car table) (cons 'hline (cdr table)))
 154     table))
 155
 156 (defun org-babel-prep-session:sqlite (session params)
 157   "Raise an error because support for SQLite sessions isn't implemented.
 158 Prepare SESSION according to the header arguments specified in PARAMS."
 159   (error "SQLite sessions not yet implemented"))
 160
 161 (provide 'ob-sqlite)
 162
 163
 164
 165 ;;; ob-sqlite.el ends here