4.4 Wrapping Long Lines

Most of the PO editors do not wrap long lines that inevitably appear in msgstrs. If that happens, long lines make reading subsequent diffs harder, and are generally annoying for most people. If this issue bothers you, you can “normalize” the already finished PO translation by executing on the command line msgcat -o file.po file.po, before installing it in the repository. Either way, the build system will treat it as a valid PO file.

For those lucky Emacs users, here is a code snippet that you can put in your .emacs; doing M-x po-wrap while in PO mode will wrap all long lines:

(defun po-wrap ()
  "Filter current po-mode buffer through `msgcat' tool to wrap all lines."
  (interactive)
  (if (eq major-mode 'po-mode)
      (let ((tmp-file (make-temp-file "po-wrap."))
	    (tmp-buf (generate-new-buffer "*temp*")))
	(unwind-protect
	    (progn
	      (write-region (point-min) (point-max) tmp-file nil 1)
	      (if (zerop
		   (call-process
		    "msgcat" nil tmp-buf t (shell-quote-argument tmp-file)))
		  (let ((saved (point))
			(inhibit-read-only t))
		    (delete-region (point-min) (point-max))
		    (insert-buffer tmp-buf)
		    (goto-char (min saved (point-max))))
		(with-current-buffer tmp-buf
		  (error (buffer-string)))))
	  (kill-buffer tmp-buf)
	  (delete-file tmp-file)))))

It is highly desirable that you check if the PO file you finished translating (or editing) is valid, before committing it. This is done by running msgfmt -cv -o /dev/null file or by simply pressing V in PO mode. The build system automatically verifies each PO file when invoked with VALIDATE=yes, but you won’t get a warm and fuzzy feeling if a stupid typo you made halts the whole update of all translations. Such things happen to everyone, so it is a good practice to check before you actually commit.