Re: [O] Overriding org-html-headline or other export functions?

[Charles C. Berry]

On Mon, 29 May 2017, Brett Viren wrote:

> Hi,
>
> I am writing a manual in Org which gets exported/published to HTML and
> styled with org-html-themes.  I want the HTML to include a little icon
> next to each headline which is a direct link to the headline itself.
> Basically, I want to rip off what GitHub does when it renders Org.
>
> First, is there some way to achieve this headline link without
> explicitly adding it in the Org text or diving into Org Elisp?
>
> I couldn't find one so I took the latter route by copying out the whole
> of org-html-headline into the Emacs init Elisp file I used for
> publishing and fiddle with it until I got more or less what I wanted.
> Here are the lines tweaked:
>
>  https://github.com/WireCell/wire-cell-docs/blob/master/manuals/publish.el#L69
>
> Here is an example of the result:
>
>  http://www.phy.bnl.gov/~bviren/wirecell.github.io/manual.html
>
> Is this copy+hack the proper way to tweak the exporting in this case?
> In particular, I worry about my copy of org-html-headline diverging from
> the real.
>
>
> I read about export filters and extending an existing back-end, but I
> think these do not apply, but maybe I have that wrong.

You do have that wrong.  This is exactly what export filters and derived 
backends are for.  In fact, you can use both.  For an example, see

http://orgmode.org/worg/exporters/filter-markup.html

You will want to change `latex' to `html' in the

        `(org-export-define-derived-backend ...)'

call and delete all filters except for `:filter-headline'.  And revise 
`ox-mrkup-filter-headline' accordingly.

And of course, you will want to look at

http://orgmode.org/worg/dev/org-export-reference.html

HTH,

Chuck