[elpa] externals/tempel 3659036edb 1/2: Optional named field argument for custom user element hooks

[ELPA Syncer]

branch: externals/tempel
commit 3659036edbc332746dec556d0dec69ac4c52dcac
Author: Daniel Mendler <mail@daniel-mendler.de>
Commit: Daniel Mendler <mail@daniel-mendler.de>

    Optional named field argument for custom user element hooks
    
    Fix #153
    
    Co-authored-by: Taro Sato <okomestudio@gmail.com>
---
 README.org | 23 +++++++++++++++++++++++
 tempel.el  |  8 +++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/README.org b/README.org
index e02d1be100..690fcd79c8 100644
--- a/README.org
+++ b/README.org
@@ -345,6 +345,29 @@ The following example templates uses the newly defined 
include element.
 (package (i header) r n n (i provide))
 #+end_src
 
+If a custom user element needs an access to named fields, the hook function
+should take the second argument ~fields~, which refers to an alist that maps 
the
+field name to its value in the current template. For example here we define a
+custom element ~*~ to repeat a template a number of times:
+
+#+begin_src emacs-lisp
+(defun tempel-repeat (elt fields)
+  (pcase elt
+    (`(* ,count . ,rest)
+     (cons 'l (cl-loop for i below (eval count fields) append rest)))))
+(add-to-list 'tempel-user-elements #'tempel-repeat)
+#+end_src
+
+The ~*~ custom element can be used to expand dynamic tables:
+
+#+begin_src emacs-lisp
+(table (p (read-number "Rows: ") rows noinsert)
+       (p (read-number "Cols: ") cols noinsert)
+       "| " (p "  ") (* (1- cols) " | " (p "  ")) " |" n
+       "|" (* cols "----|") n
+       (* rows "| " (p "  ") (* (1- cols) " | " (p "  ")) " |" n))
+#+end_src
+
 * Adding template sources
 
 Tempel offers a flexible mechanism for providing the templates, which are
diff --git a/tempel.el b/tempel.el
index 70b34e8135..9804a52033 100644
--- a/tempel.el
+++ b/tempel.el
@@ -366,7 +366,13 @@ Return the added field."
          (indent-region (car region) (cdr region) nil))))
     ;; TEMPEL EXTENSION: Quit template immediately
     ('q (overlay-put (tempel--field st) 'tempel--enter #'tempel--done))
-    (_ (if-let ((ret (run-hook-with-args-until-success 'tempel-user-elements 
elt)))
+    (_ (if-let ((ret (run-hook-wrapped 'tempel-user-elements
+                                       (lambda (hook elt fields)
+                                         (condition-case nil
+                                             (funcall hook elt)
+                                           (wrong-number-of-arguments
+                                            (funcall hook elt fields))))
+                                       elt (cdr st))))
            (tempel--element st region ret)
          ;; TEMPEL EXTENSION: Evaluate forms
          (tempel--form st elt)))))