[Erc-commit] [commit][master] Add ability to specify a "filter function" for logging

[mwolson]

commit f0aaf9083b3f18d75fbcdf685a07a772c8ae5d69
Author: Michael W. Olson <address@hidden>
Date:   Sat Sep 8 02:23:44 2007 -0400

    Add ability to specify a "filter function" for logging
    
    * erc-log.el (erc-log-filter-function): New option that specifies the
      function to call for filtering text before writing it to a log file.
      Thanks to David O'Toole for the suggestion.
      (erc-save-buffer-in-logs): Use erc-log-filter-function.  Make sure we
      carry along the value of coding-system-for-write, because this could
      potentially be shadowed by the temporary buffer.

diff --git a/ChangeLog b/ChangeLog
index c3abd83..b332c3c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2007-09-08  Michael Olson  <address@hidden>
 
+       * erc-log.el (erc-log-filter-function): New option that specifies
+       the function to call for filtering text before writing it to a log
+       file.  Thanks to David O'Toole for the suggestion.
+       (erc-save-buffer-in-logs): Use erc-log-filter-function.  Make sure
+       we carry along the value of coding-system-for-write, because this
+       could potentially be shadowed by the temporary buffer.
+
        * erc.el (erc-version-string): Update to 5.3, development version.
 
 2007-09-07  Glenn Morris  <address@hidden>
diff --git a/erc-log.el b/erc-log.el
index 856f1dc..1733b3d 100644
--- a/erc-log.el
+++ b/erc-log.el
@@ -205,6 +205,16 @@ This should ideally, be a \"catch-all\" coding system, like
 `emacs-mule', or `iso-2022-7bit'."
   :group 'erc-log)
 
+(defcustom erc-log-filter-function nil
+  "*If non-nil, pass text through the given function before writing it to
+a log file.
+
+The function should take one argument, which is the text to filter."
+  :group 'erc-log
+  :type '(choice (function "Function")
+                (const :tag "No filtering" nil)))
+
+
 ;;;###autoload (autoload 'erc-log-mode "erc-log" nil t)
 (define-erc-module log nil
   "Automatically logs things you receive on IRC into files.
@@ -405,17 +415,25 @@ You can save every individual message by putting this 
function on
   (or buffer (setq buffer (current-buffer)))
   (when (erc-logging-enabled buffer)
     (let ((file (erc-current-logfile buffer))
-         (coding-system-for-write erc-log-file-coding-system))
+         (coding-system erc-log-file-coding-system))
       (save-excursion
        (with-current-buffer buffer
          (save-restriction
            (widen)
-           ;; early on in the initalisation, don't try and write the log out
+           ;; early on in the initialization, don't try and write the log out
            (when (and (markerp erc-last-saved-position)
                       (> erc-insert-marker (1+ erc-last-saved-position)))
-             (write-region (1+ (marker-position erc-last-saved-position))
-                           (marker-position erc-insert-marker)
-                           file t 'nomessage)
+             (let ((start (1+ (marker-position erc-last-saved-position)))
+                   (end (marker-position erc-insert-marker)))
+               (if (functionp erc-log-filter-function)
+                   (let ((text (buffer-substring start end)))
+                     (with-temp-buffer
+                       (insert (funcall erc-log-filter-function text))
+                       (let ((coding-system-for-write coding-system))
+                         (write-region (point-min) (point-max)
+                                       file t 'nomessage))))
+                 (let ((coding-system-for-write coding-system))
+                   (write-region start end file t 'nomessage))))
              (if (and erc-truncate-buffer-on-save (interactive-p))
                  (progn
                    (let ((inhibit-read-only t)) (erase-buffer))