Interactive functions do not have double-dashes in their names. However,
I have concerns about this interactive status. Given than the function
is not properly documented in the manual, there is little chance it will
be actually used. And if it isn't, it could return surprising results.
Another idea would be to replace NOCACHE with CLEAR-CACHE. When this is
non-nil, the cache is reset at the beginning of the function. The point
is to reset the cache the first time the function is called, but not on
recursive calls, which ensures any file is retrieved only once.
Of
course the cache doesn't survive to multiple exports, but at least it is
transparent to the user.
Yet another idea is to add a time-to-live to cached values and remove
them from cache past it. However, I prefer the idea above.
The specific reason is, as you noticed, %S wraps file name within double
quotes. IMO, `...' would be for symbols or key bindings.
`prog1' is difficult to read when the first SEXP is large. Also, we
should avoid splitting error messages and constructing them back, for
hypothetical i18n considerations.
I suggest the following re-factoring, where I limited the number of
bindings and remove some trivial comments.
(defun org-file-contents (file &optional noerror nocache)
"Return the contents of FILE, as a string.
FILE can be a file name or URL.
If FILE is a URL, download the contents. If the URL contents are
already cached in the `org--file-cache' hash table, the download step
is skipped.
If NOERROR is non-nil, ignore the error when unable to read the FILE
from file or URL.
If NOCACHE is non-nil, do a fresh fetch of FILE even if cached version
is available. This option applies only if FILE is a URL."
(let* ((is-url (org-file-url-p file))
(cache (and is-url
(not nocache)
(gethash file org--file-cache))))
(cond
(cache)
(is-url
(with-current-buffer (url-retrieve-synchronously file)
(goto-char (point-min))
(if (re-search-forward "HTTP.*\\s-+200\\s-OK" nil t)
;; URL retrieved correctly. Move point to after the
;; url-retrieve header, update the cache `org--file-cache'
;; and return contents.
(progn
(search-forward "\n\n" nil 'move)
(puthash file
(buffer-substring-no-properties (point) (point-max))
org--file-cache))
(funcall (if noerror #'message #'user-error)
(format "Unable to fetch file from %S" file)))))
(t
(with-temp-buffer
(condition-case err
(progn (insert-file-contents file) (buffer-string))
(file-error
(funcall (if noerror #'message #'user-error)
(error-message-string err)))))))))
I'm not sure about the return value when NOERROR is non-nil, but it may
not matter, per the suggestion above.
> Do we need to update the code using org-file-contents in these places:
What do you meant by "update"?
Kaushal Modi