[PATCH] emacs: hello: allow extras to add to saved-search defcustom

[Mark Walters]

This adds an extra variable notmuch-saved-search-extras that allows
the user to add extra options to the saved-search customize
variable. Of course it is up to them to make these extra options do
anything afterwards.

The difficulty is that the code definining a defcustom is executed
when the the file is first read which would normally occur before any
optional extras are loaded.

To get around this I suggest that extras that wish to use this
infrastucture add a helper loader file that does something like
the following (this example is for a tweaked version of Austin's notmuch-go)

(defvar notmuch-saved-search-extras nil)

(setq notmuch-saved-search-extras
      (append notmuch-saved-search-extras
	      '((checklist :inline t
			   :format "%v"
			   (group :format "%v"
				  :inline t
				  (const :format "     Go key: " :go.key)
				  (key-sequence :format "%v"))))))

(eval-after-load 'notmuch '(require 'notmuch-go))

(provide 'notmuch-go-loader)

The user should then (require 'notmuch-go-loader) before loading notmuch.
---

The patch below is quite simple: almost all of the diff is
whitespace. The more difficult part to get right was the above code
snippet. It would be nice if a single file could say "don't read the
following code until feature 'notmuch is present" but I don't know how
to do that cleanly.

The above at least means that it is simple from a user's
perspective. And all that happens if they do load the extension after
notmuch is that the defcustom is not updated and that is unavoidable.

Best wishes

Mark

 emacs/notmuch-hello.el |   28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/emacs/notmuch-hello.el b/emacs/notmuch-hello.el
index 3de5238..e627f42 100644
--- a/emacs/notmuch-hello.el
+++ b/emacs/notmuch-hello.el
@@ -76,21 +76,25 @@ (defun notmuch-hello--saved-searches-to-plist (symbol)
   (let ((saved-searches (default-value symbol)))
     (mapcar #'notmuch-hello-saved-search-to-plist saved-searches)))
 
+(defvar notmuch-saved-search-extras nil
+  "Extra formats to add to defcustom saved search widget")
+
 (define-widget 'notmuch-saved-search-plist 'list
   "A single saved search property list."
   :tag "Saved Search"
-  :args '((list :inline t
-		:format "%v"
-		(group :format "%v" :inline t (const :format "   Name: " :name) (string :format "%v"))
-		(group :format "%v" :inline t (const :format "  Query: " :query) (string :format "%v")))
-	  (checklist :inline t
-		     :format "%v"
-		     (group :format "%v" :inline t (const :format "Count-Query: " :count-query) (string :format "%v"))
-		     (group :format "%v" :inline t (const :format "" :sort-order)
-			    (choice :tag " Sort Order"
-				    (const :tag "Default" nil)
-				    (const :tag "Oldest-first" oldest-first)
-				    (const :tag "Newest-first" newest-first))))))
+  :args (append '((list :inline t
+			:format "%v"
+			(group :format "%v" :inline t (const :format "   Name: " :name) (string :format "%v"))
+			(group :format "%v" :inline t (const :format "  Query: " :query) (string :format "%v")))
+		  (checklist :inline t
+			     :format "%v"
+			     (group :format "%v" :inline t (const :format "Count-Query: " :count-query) (string :format "%v"))
+			     (group :format "%v" :inline t (const :format "" :sort-order)
+				    (choice :tag " Sort Order"
+					    (const :tag "Default" nil)
+					    (const :tag "Oldest-first" oldest-first)
+					    (const :tag "Newest-first" newest-first)))))
+		notmuch-saved-search-extras))
 
 (defcustom notmuch-saved-searches '((:name "inbox" :query "tag:inbox")
 				    (:name "unread" :query "tag:unread"))
-- 
1.7.10.4