Re: How to use http-get properly in code

[Thien-Thi Nguyen <ttn@glug.org>]

Mathias Dahl <brakjoller@gmail.com> writes:

> ;; The sentinel
> (defun ef-http-get-sentinel (proc message)
>   (save-excursion
>     (set-buffer (process-buffer proc))
>     (setq ef-response-xml
>           (xml-parse-region (point-min) (point-max)))))

you are confusing a sentinel and a process output filter.
the former is called on changes to process state (e.g., hangup).
this function (above) is an example of the latter.

> How do I get around this? I have been thinking about adding a
> loop that waits for some flag that the sentinel sets when it has
> fetched the data, and then when the flag is found to be true,
> continue with the code, but that feels ugly.

that approach makes the code behave synchronously, which is what
you want.  (it's ok to want "ugly" yet useful things, sometimes.)
see `gnugo-synchronous-send/return' in gnugo.el, somewhere under:

  http://www.glug.org/people/ttn/software/personal-elisp/

for an example.  there are lots of synchronous examples, but fewer
asynchronous ones, because doing asynchronous right is more hairy.
see the page beginning with "GNU Go vs GNU Go" in gnugo-extra.el
(also under the aforementioned directory) for an example of
classic(ish) asynchronous design.

thi