Re: Buttons in help buffer that displays contents of variables

[Stephen Berman]

On Sat, 22 Jul 2023 22:42:55 +0000 Heime <heimeborgia@protonmail.com> wrote:

> ------- Original Message -------
> On Sunday, July 23rd, 2023 at 10:28 AM, Stephen Berman
> <stephen.berman@gmx.net> wrote:
>
>
>> On Sat, 22 Jul 2023 22:13:25 +0000 Heime heimeborgia@protonmail.com wrote:
>> 
>> 
>> [...]
>> 
>> > > > > > > > The error says the function my-action expects one argument, 
>> > > > > > > > but you
>> > > > > > > > defined it with an empty argument list. If you don't want to 
>> > > > > > > > use the
>> > > > > > > > argument, you can use `' as a placeholder for the required 
>> > > > > > > > argument,
>> > > > > > > > which will be ignored by the byte compiler:
>> > > > > > > > 
>> > > > > > > > (defun my-action ()
>> > > > > > > > "Function to be executed when the button is clicked."
>> > > > > > > > (interactive)
>> > > > > > > > (message "%s" myvar))
>> > > > > > > > 
>> > > > > > > > Steve Berman
>> > 
>> > Do you know what the single argument is used for ?
>> 
>> 
>> This is explained in the Info node `(elisp) Manipulating Buttons': Where a
>> BUTTON parameter is specified, it means an object referring to a specific
>> button, either an overlay (for overlay buttons), or a buffer-position or
>> marker (for text property buttons). Such an object is passed as the first
>> argument to a button’s invocation function when it is invoked. See also the
>> function` button-activate' described in that node.
>> 
>> Steve Berman
>
> What would be the actual object name passed to the function ?

I'm not sure what you mean by "actual object name", but since the
parameter is a local variable of the function, you can use any name for
it you like, including, as noted above, the underscore `_' (which seems
to have been removed by your mail program in the above citation), if you
don't use it in the body of the function.

Steve Berman