AUCTeX beamer class does not auto-insert section label

Question

I am now using AUCTeX 11.89.1 on emacs. When I start a beamer class document, the label is not automatically added after using C-c C-s to start a new section. I have to use C-c C-( to add the label afterwards. If I use C-c C-e to insert some environment (e.g., equation), the label is added automatically.

This does not happen in the usual article class, in which labels are automatically added. I have the following in my .emacs file,

(setq reftex-plug-into-AUCTeX t)
(add-hook 'LaTeX-mode-hook 'reftex-mode)

Do I need anything else to make it work in beamer?

P.S., I always use C-u C-c C-n to make sure that the current documentclass is recognized first.

Answer 1

Some AUCTeX styles can be customized, viz.:

• amsmath.el
• beamer.el
• biblatex.el
• comment.el
• csquotes.el
• emp.el
• fontspec.el
• graphicx.el

beamer.el usesLaTeX-beamer-section-labels-flag which defaults to nil:

LaTeX-beamer-section-labels-flag is a variable defined in ‘tex-style.el’.
Its value is nil

Documentation:
If non-nil section labels are added

If you set this variable to t, AUCTeX (or RefTeX) will ask you for a label when you insert a sectioning command with C-c C-s. You can set this variable in your .emacs with

(setq LaTeX-beamer-section-labels-flag t)

or use customize with M-x customize-group RET LaTeX-style RET.

The relevant code in beamer.el is:

(unless LaTeX-beamer-section-labels-flag
  (make-local-variable 'LaTeX-section-hook)
  (setq LaTeX-section-hook
    '(LaTeX-section-heading
      LaTeX-section-title
      LaTeX-section-section)))

where LaTeX-section-label is omitted.