mu4e/server: get cached list of labels

This will be useful with label commands.

mu4e/mu4e-search.el

@@ -154,6 +154,9 @@ but also manually invoked searches."
   :type 'hook
   :group 'mu4e-search)
 
+(defvar mu4e-labels-list nil
+  "Cached list of labels.")
+
 ;; Internals
 
 ;;; History

mu4e/mu4e-server.el

@@ -130,6 +130,7 @@ Note: this REPL is not to be confused with the mu REPL as per
 
 ;; Cached data
 (defvar mu4e-maildir-list)
+(defvar mu4e-labels-list)
 
 ;; Handlers are not strictly internal, but are not meant
 ;; for overriding outside mu4e. The are mainly for breaking
@@ -470,6 +471,8 @@ The server output is as follows:
          ;; get some data
          ((plist-get sexp :maildirs)
           (setq mu4e-maildir-list (mu4e--server-plist-get sexp :maildirs)))
+         ((plist-get sexp :labels)
+          (setq mu4e-labels-list (mu4e--server-plist-get sexp :labels)))
 
          ;; receive an error
          ((plist-get sexp :error)
@@ -654,7 +657,7 @@ get at most MAX contacts."
 
 (defun mu4e--server-data (kind)
   "Request data of some KIND.
-KIND is a symbol. Currently supported kinds: maildirs."
+KIND is a symbol. One of maildirs, labels."
   (mu4e--server-call-mu
    `(data :kind ,kind)))
 

mu4e/mu4e.el

@@ -160,8 +160,9 @@ invoke FUNC (if available) afterwards."
   (add-hook 'mu4e-query-items-updated-hook #'mu4e--main-redraw)
   (setq mu4e--initialized t) ;; last before we call the server.
   (mu4e--server-ping)
-  ;; ask for the maildir-list
+  ;; ask for the maildir-list and labels
   (mu4e--server-data 'maildirs)
+  (mu4e--server-data 'labels)
   ;; maybe request the list of contacts, automatically refreshed after
   ;; re-indexing
   (mu4e--query-items-refresh 'reset-baseline)
@@ -249,7 +250,9 @@ invoke FUNC (if available) afterwards."
           (unless (and (not (string= mu4e--contacts-tstamp "0"))
                        (zerop (plist-get info :updated)))
             (mu4e--request-contacts-maybe)
-            (mu4e--server-data 'maildirs)) ;; update maildir list
+            (mu4e--server-data 'maildirs)
+            (mu4e--server-data 'labels)) ;; update maildir/labels list
+
           (mu4e--main-redraw))))
      ((plist-get info :message)
       (mu4e-index-message "%s" (plist-get info :message))))))