enable the helm integration only if helm is present

projectile.el

@@ -6,7 +6,7 @@
 ;; Author: Bozhidar Batsov
 ;; URL: http://www.emacswiki.org/cgi-bin/wiki/Projectile
 ;; Git: git://github.com/bbatsov/projectile.git
-;; Version: 0.4
+;; Version: 0.5
 ;; Created: 2011-31-07
 ;; Keywords: project, convenience
 ;; EmacsWiki: Projectile
@@ -226,37 +226,37 @@
      ["Regenerate etags" projectile-regenerate-tags])))
 
 ;; Helm integration
-(defun helm-c-projectile-list ()
-  "Generates a list of files in the current project"
-  (projectile-get-project-files
-   (projectile-get-project-root)))
-
-(defvar helm-c-projectile-cache nil)
-
-(defvar helm-c-source-projectile
-  `((name . "Projectile")
-    (init . (lambda ()
-              (setq helm-c-projectile-cache
-                    (helm-c-projectile-list))))
-    ;; Needed for filenames with capitals letters.
-    (disable-shortcuts)
-    (candidates . helm-c-projectile-cache)
-    (volatile)
-    (keymap . ,helm-generic-files-map)
-    (help-message . helm-generic-file-help-message)
-    (mode-line . helm-generic-file-mode-line-string)
-    (match helm-c-match-on-basename)
-    (type . file))
-  "Helm source definition")
-
-(defun helm-projectile ()
-  "Example function for calling Helm with the projectile file source.
+(when (fboundp 'helm)
+  (defun helm-c-projectile-list ()
+    "Generates a list of files in the current project"
+    (projectile-get-project-files
+     (projectile-get-project-root)))
+
+  (defvar helm-c-projectile-cache nil)
+
+  (defvar helm-c-source-projectile
+    `((name . "Projectile")
+      (init . (lambda ()
+                (setq helm-c-projectile-cache
+                      (helm-c-projectile-list))))
+      ;; Needed for filenames with capitals letters.
+      (disable-shortcuts)
+      (candidates . helm-c-projectile-cache)
+      (volatile)
+      (keymap . ,helm-generic-files-map)
+      (help-message . helm-generic-file-help-message)
+      (mode-line . helm-generic-file-mode-line-string)
+      (match helm-c-match-on-basename)
+      (type . file))
+    "Helm source definition")
+
+  (defun helm-projectile ()
+    "Example function for calling Helm with the projectile file source.
 
 Use this function as example and create your own list of Helm sources.
 "
-  (interactive)
-  (helm-other-buffer 'helm-c-source-projectile "*helm projectile*"))
-
+    (interactive)
+    (helm-other-buffer 'helm-c-source-projectile "*helm projectile*")))
 ;; define minor mode
 (define-globalized-minor-mode projectile-global-mode projectile-mode projectile-on)