Re: [PATCH] Re: \newpage in HTML export

[Nicolas Goaziou <n.goaziou@gmail.com>]

Hello,

Eric Abrahamsen <eric@ericabrahamsen.net> writes:

> Here's a fairly simple first stab, with page breaks made into an
> element, and a sample handling in the LaTeX backend. I've hardcoded ^L
> and the page-delimiter regexp that finds it, not sure it's worth
> providing an org-page-delimiter shadow. For now, use C-q C-l to insert
> the control character.

Thanks for the patch.

Anyway, I don't think this is a good idea to introduce a new syntax just
to avoid a one-liner (or a hook, see below). Also, this would only make
sense in few export back-ends.

Really, introducing new syntax has a cost, so you have to ponder if it's
really useful, because, once installed, every Org user will have to pay
the price for it.

In the same vein, we have a couple of dubious syntactical elements which
probably sound great for a few users but don't make much sense in most
cases (e.g. quote sections, which can be replaced with an example(!)
block and comments blocks, which can be replaced with a regular
comment).

Admittedly, in this particular case, that cost isn't very high, but
I think it would nonetheless add up to the list of hardly-used syntax
category.

> If this passes muster I can go through the other backends and add
> page-break handling where it makes sense. If not, I'll just keep it on
> my local branch!

You don't need such a patch. For example, you can install the following:

  (defun my-page-delimiter-hook (backend)
    (while (re-search-forward page-delimiter nil t)
      (replace-match
       (cond
        ((org-export-derived-backend-p backend 'latex)
         "#+LATEX: \\\\newpage")
        ((org-export-derived-backend-p backend 'html)
         "#+HTML: <div style=\"page-break-before: always\">&nbsp;</div>")
        ;; Ignore page delimiters in other back-ends.
        (t "")))))

  (add-hook 'org-export-before-parsing-hook 'my-page-delimiter-hook)

Obviously, you can handle as many back-ends as you see fit in
`my-page-delimiter-hook'.

Here are a few comments about the code:

>  (defconst org-element-all-objects
>    '(bold code entity export-snippet footnote-reference inline-babel-call
> -	 inline-src-block italic line-break latex-fragment link macro
> +	 inline-src-block italic line-break latex-fragment link macro page-break
>  	 radio-target statistics-cookie strike-through subscript superscript
>  	 table-cell target timestamp underline verbatim)
>    "Complete list of object types.")

Since `page-break' is an element type, you cannot make it also an object
type.

Also, you would need to update `org-element-paragraph-separate' regexp.

>  (defun org-element-paragraph-parser (limit affiliated)
> @@ -3845,6 +3879,8 @@ element it has to parse."
>  	     ;; Horizontal Rule.
>  	     ((looking-at "[ \t]*-\\{5,\\}[ \t]*$")
>  	      (org-element-horizontal-rule-parser limit affiliated))
> +	     ((looking-at page-delimiter)
> +	      (org-element-page-break-parser limit affiliated))

Using `page-delimiter' is not desirable because it implies that its
syntax is customizable, which would go against the last syntax patches
(changing defcustoms into defconsts whenever possible). Customizable
syntax cripples portability: please use it with care.


Regards,

-- 
Nicolas Goaziou