可以说我们有以下结构:
|Element |Price |
|first |1 |
|second |2 |
|Total |:=vsum(@2..@-1)| -> this will render: 3
#+TBLFM: @4$2=vsum(@2..@-1)
现在让我们说插入一个新行:
|Element |Price |
|first |1 |
|inserted |10 |
|second |2 |
|Total |:=vsum(@2..@-1)| -> this will still render 3, but it should render 13
#+TBLFM: @5$2=vsum(@2..@-1)
那么当用新值插入新行时,如何自动更改总和?
Org-mode has limited ability to automatically recalculate tables:第一列可以用来添加一个特殊字符(#
),它可以做你想要的,但只有当你想要重新计算的行中输入TAB
,S-TAB
或RET
时(请注意,这也会添加此行)对缓冲区的全局重新计算也可能有用)。
这里的问题是org-mode不知道何时应该重新计算表,除非你告诉它(例如使用命令C-c *
(org-ctrl-c-star
))。一种选择是重新绑定org-mode
中的一些或所有移动键绑定,以查看游标是否已启动并已移出表条目,如果是,则重新计算整个表,但我建议不要这样做。
在我看来,更好更容易的解决方案是在插入新行时让org-mode自动更新表(但不一定每次条目更改时)。这是一个Emacs Lisp函数(my-org-table-insert-row-and-recalculate-table
),它通过提示用户输入每一列,然后重新计算表的所有公式,在当前函数之上创建一个新行。关于此功能的一些注意事项:
#+TBLFM: $2=vsum(@2..@-1)
将不适用于任何插入,因为org-mode尝试将其应用于参考@-1
无效的第1列第2列)。(require 'subr-x)
(defun remove-empty-strings-list (list)
(if (null list)
'()
(let ((rest (remove-empty-strings-list (cdr list))))
(if (string= (car list) "")
rest
(cons (car list) rest)))))
(defun my-org-table--get-row-as-list ()
(unless (org-at-table-p) (user-error "Not at a table"))
(let ((line (buffer-substring-no-properties (line-beginning-position) (line-end-position))))
(mapcar 'string-trim (remove-empty-strings-list (split-string line "|")))))
(defun my-org-table--get-top-row-as-list ()
(save-excursion
(org-table-goto-line 1)
(my-org-table--get-row-as-list)))
(defun my-org-table--insert-string-row-and-recalculate-table (string)
(org-table-with-shrunk-columns
(beginning-of-line 1)
(insert-before-markers string "\n")
(org-table-align)
(org-table-fix-formulas "@" nil (1- (org-table-current-dline)) 1)
(org-table-iterate)))
(defun my-org-table--prompt-row ()
(unless (org-at-table-p) (user-error "Not at a table"))
(let ((top-row-list (my-org-table--get-top-row-as-list))
(new-str "|")
(cur-col 1))
(dolist (top-item top-row-list)
(let ((new-entry
(read-string (concat "Enter entry (column #"
(number-to-string cur-col)
" - first entry: "
top-item
"): "))))
(setq new-str (concat new-str new-entry "|")) ;; test placement
(setq cur-col (+ 1 cur-col))))
new-str))
(defun my-org-table-insert-row-and-recalculate-table ()
"Interactively inserts row above point and then recalculates table"
(interactive)
(unless (org-at-table-p) (user-error "Not at a table"))
(my-org-table--insert-string-row-and-recalculate-table (my-org-table--prompt-row)))
示例用法('!!'表示缓冲区中的点,'>>'是迷你缓冲区提示符):
| Element | Price |
| first | 1 |
| second | 2 |!!
| Total | 3 |
#+TBLFM: @4$2=vsum(@2..@-1)
运行M-x my-org-table-insert-row-and-recalculate-table
。
>> Enter entry (column #1 - first entry: Element):
inserted
>> Enter entry (column #2 - first entry: Price):
100
输出:
| Element | Price |
| first | 1 |
| inserted | 100 |
| second | 2 |
| Total | 103 |
#+TBLFM: @5$2=vsum(@2..@-1)