From 3d5dc61c1565695e797936af1f2eb50cd5460c95 Mon Sep 17 00:00:00 2001
From: "Kevin J. Foley" <kevin@kevinjfoley.me>
Date: Sat, 13 Feb 2021 12:04:38 -0500
Subject: [PATCH] org-agenda.el: Support argument collection for custom bulk
 functions

* lisp/org-agenda.el (org-agenda-bulk-custom-functions): Add
documentation about argument collection for custom bulk functions.
(org-agenda-bulk-action): Support function to collect arguments for
custom bulk functions.
* etc/ORG-NEWS (Option ~org-agenda-bulk-custom-functions~ now supports
collecting bulk arguments): Add entry to NEWS.
---
 etc/ORG-NEWS       |  7 +++++++
 lisp/org-agenda.el | 34 +++++++++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 5e5f1954d..d7de97e2c 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -81,6 +81,13 @@ block. ~org-babel-latex-preamble~, ~org-babel-latex-begin-env~ and
 the user to specify the preamble and code that preceedes and proceeds
 the contents of the source block.
 
+*** Option ~org-agenda-bulk-custom-functions~ now supports collecting bulk arguments
+
+When specifying a custom agenda bulk option, you can now also specify
+a function which collects the arguments to be used with each call to
+the custom function.
+
+
 ** New features
 *** =ob-python= improvements to =:return= header argument 
 
diff --git a/lisp/org-agenda.el b/lisp/org-agenda.el
index dedf7e5bb..42d127232 100644
--- a/lisp/org-agenda.el
+++ b/lisp/org-agenda.el
@@ -2080,9 +2080,25 @@ (defcustom org-agenda-bulk-custom-functions nil
 
 With selected entries in an agenda buffer, `B R' will call
 the custom function `set-category' on the selected entries.
-Note that functions in this alist don't need to be quoted."
-  :type '(alist :key-type character :value-type (group function))
-  :version "24.1"
+Note that functions in this alist don't need to be quoted.
+
+You can also specify a function which collects arguments to be
+used for each call to your bulk custom function.  The argument
+collecting function will be run once and should return a list of
+arguments to pass to the bulk function.  For example:
+
+  \\='((?R set-category get-category))
+
+Now, `B R' will call the custom `get-category' which would prompt
+the user once for a category.  That category is then passed as an
+argument to `set-category' for each entry it's called against."
+  :type
+  '(alist :key-type character
+	  :value-type
+          (group (function :tag "Bulk Custom Function")
+		 (choice (function :tag "Bulk Custom Argument Function")
+		         (const :tag "No Bulk Custom Argument Function" nil))))
+  :package-version '(Org . "9.5")
   :group 'org-agenda)
 
 (defmacro org-agenda-with-point-at-orig-entry (string &rest body)
@@ -10486,10 +10502,14 @@ (defun org-agenda-bulk-action (&optional arg)
 		(completing-read "Function: " obarray #'fboundp t nil nil))))
 
 	(action
-	 (pcase (assoc action org-agenda-bulk-custom-functions)
-	   (`(,_ ,f) (setq cmd f) (setq redo-at-end t))
-	   (_ (user-error "Invalid bulk action: %c" action)))))
-
+	 (pcase-let (`(,_ ,fn ,arg-fn)
+                     (assoc action org-agenda-bulk-custom-functions))
+           (if (not fn)
+               (user-error "Invalid bulk action: %c" action)
+             (when (functionp arg-fn)
+               (setq fn (apply #'apply-partially fn (funcall arg-fn))))
+             (setq cmd fn)
+             (setq redo-at-end t)))))
       ;; Sort the markers, to make sure that parents are handled
       ;; before children.
       (setq entries (sort entries
-- 
2.28.0