Re: Hook Function Examples

[Nick Dokos <nicholas.dokos@hp.com>]

Mark Elston <m_elston@comcast.net> wrote:

> I am trying to make use of some of the hooks for exporting and haven't
> found any docs about what they take or how to make use of them (elisp
> is *not* my native language).
> 

The Emacs Lisp Reference manual has a section (23.1: Hooks) on hooks,
but I'm not sure how helpful it will be to you. The most important note
is that "normal" hook variables are, by convention, named
<foo>-hook. "normal" means that the functions that are added to the hook
take no arguments and return no useful values.

> In particular, I am trying to figure out how to use the following
> to see if any of them are going to help me:
> 
>  org-export-preprocess-hook
>  org-export-preprocess-after-tree-selection-hook
>  org-export-preprocess-final-hook
> 
> Any examples of a hook function for these would help a lot.  In
> particular, what are the parameters, is the point "looking at"
> anything in particular, etc.
> 

Use the source, Luke! (erm... Mark!)

 C-h v org-export-preprocess-hook <RET>

gives me:

 (org-export-blocks-preprocess)

so we have here an example of a hook function!

 C-h f org-export-blocks-preprocess <RET>

gives you the function's doc string, including a link to where it is
defined, and clicking on the link will take you to the function: no
params (it is a "normal" hook after all), and I think you can make no
assumptions about the context. In particular, the above function wraps
everything in a save-excursion, goes to the beginning of the buffer and
searches for interesting things, doing something on each interesting
thing it finds.

The other two hooks are nil in my case, but I think similar things
would apply there too.

HTH,
Nick