add insert-snippet functionality to djula:view package.

src/view.lisp

@@ -39,7 +39,8 @@
 ;; Execute package definition
 
 (defpackage ritherdon-archive.djula
-  (:use #:cl)
+  (:use #:cl
+	#:storage)
   (:import-from #:files
 		#:storage-file)
   (:import-from #:ritherdon-archive.config
@@ -50,6 +51,10 @@
   (:import-from #:caveman2
 		#:url-for))
 
+;; Added 'in-package' line after default Caveman2 set-up. Needed for custom
+;; functions. Not part of Caveman2 set-up.
+(in-package #:ritherdon-archive.djula)
+
 (setf djula:*djula-execute-package* (find-package :ritherdon-archive.djula))
 
 ;; Custom filters and template code added below...
@@ -83,3 +88,8 @@
 	((str:contains? "zip" (files::file-type-of file) :ignore-case t)
 	 (format nil  "/images/icons/archive.png"))
 	(t (format nil  "/images/icons/file.png"))))
+
+(defun insert-snippet (snippet-name)
+  (if (storage:file-exists-p "" "snippets" snippet-name)
+      (format nil "~a" (storage:open-text-file "" "snippets" snippet-name))
+      (format nil "<!-- ~a not found -->" snippet-name)))