Merge pull request #45 from jethrokuan/fix/check-cache

Add org-roam--ensure-cache-built

org-roam.el

@@ -99,6 +99,12 @@ If called interactively, then PARENTS is non-nil."
   "Currently displayed file in `org-roam' buffer.")
 
 ;;; Utilities
+(defun org-roam--ensure-cache-built ()
+  "Ensures that org-roam cache is built."
+  (unless org-roam-cache
+    (org-roam--build-cache-async)
+    (user-error "Your Org-Roam cache isn't built yet! Please wait")))
+
 (defun org-roam--org-roam-file-p ()
   "Return t if file is part of org-roam system, false otherwise."
   (and (buffer-file-name (current-buffer))
@@ -460,7 +466,7 @@ This is equivalent to removing the node from the graph."
 
 (defun org-roam-update (file-path)
   "Show the backlinks for given org file for file at `FILE-PATH'."
-  (when org-roam-cache
+  (org-roam--ensure-cache-built)
   (let ((buffer-title (org-roam--get-title-or-id file-path)))
     (with-current-buffer org-roam-buffer
       (let ((inhibit-read-only t))
@@ -486,7 +492,7 @@ This is equivalent to removing the node from the graph."
                        backlinks))
           (insert "\n\n* No backlinks!")))
       (read-only-mode 1)))
-    (setq org-roam-current-file file-path)))
+  (setq org-roam-current-file file-path))
 
 ;;; Show/hide the org-roam buffer
 (define-inline org-roam--current-visibility ()
@@ -575,6 +581,7 @@ This needs to be quick/infrequent, because this is run at
 ;;; Building the Graphviz graph
 (defun org-roam-build-graph ()
   "Build graphviz graph output."
+  (org-roam--ensure-cache-built)
   (let ((forward-links (plist-get org-roam-cache :forward)))
     (with-temp-buffer
       (insert "digraph {\n")