Fixes #37. Replacing existing date

autoload/todo/txt.vim

@@ -26,7 +26,10 @@ function! s:get_current_date()
 endfunction
 
 function! todo#txt#prepend_date()
-    execute 's/^\(([a-zA-Z]) \)\?/\1' . s:get_current_date() . ' /'
+    if exists('g:todo_existing_date') && g:todo_existing_date == 'n'
+        return
+    endif
+    execute 's/^\(([a-zA-Z]) \)\?\(\d\{2,4\}-\d\{2\}-\d\{2\} \)\?/\1' . s:get_current_date() . ' /'
 endfunction
 
 function! todo#txt#mark_as_done()

doc/todo.txt

@@ -1,5 +1,11 @@
 *todo.txt*
 
+==============================================================================
+CONTENTS                                                       *todo-contents*
+
+  1. Commands ........................... |todo-commands|
+  2. Options ............................ |todo-options|
+
 ==============================================================================
 COMMANDS                                                       *todo-commands*
 
@@ -32,3 +38,17 @@ COMMANDS                                                       *todo-commands*
 `<localleader>-D` : Move completed tasks to done.txt
 
 See :h <localleader> for more information about the commands' prefix.
+
+==============================================================================
+OPTIONS                                                         *todo-options*
+
+                                                      *'g:todo_existing_date'*
+Specify the behavior of date insertion functions when the task already has a
+date of creation: >
+  let g:todo_existing_date = 'n'
+<
+  r - replace existing date (default)
+  n - do nothing
+
+===============================================================================
+vim:ft=help:et:ts=2:sw=2:sts=2:norl

test/tc_date.todo.txt

@@ -10,3 +10,15 @@ example task
 (A) Call Mom
 (B) Call Dad
 # end_date_after_priority_visual
+
+# existing_date_no_priority
+2014-05-06 example task
+# end_existing_date_no_priority
+
+# existing_date_after_priority
+(A) 2014-05-06 Call Mom
+# end_existing_date_after_priority
+
+# existing_date_do_nothing
+2014-05-06 example task
+# end_existing_date_do_nothing

test/tc_date.vim

@@ -22,6 +22,10 @@ let s:DATE_INSERTED_AFTER_PRIORITY_VISUAL = [
       \ '(B) ' . s:TODAY . ' Call Dad',
       \ ]
 
+let s:DATE_INSERTED_DO_NOTHING = [
+      \ '2014-05-06 example task',
+      \ ]
+
 function! s:tc.test_insert_date_normal_mode()
   call self.data.goto('lorem_ipsum')
   call todo#txt#prepend_date()
@@ -49,4 +53,21 @@ function! s:tc.test_insert_date_after_priority_visual_mode()
   call self.assert_equal(s:DATE_INSERTED_AFTER_PRIORITY_VISUAL, self.data.get('date_after_priority_visual'))
 endfunction
 
+function! s:tc.test_insert_with_existing_date()
+  call self.data.execute('call todo#txt#prepend_date()', 'existing_date_no_priority')
+  call self.assert_equal(s:DATE_INSERTED, self.data.get('existing_date_no_priority'))
+endfunction
+
+function! s:tc.test_insert_with_existing_date_and_priority()
+  call self.data.execute('call todo#txt#prepend_date()', 'existing_date_after_priority')
+  call self.assert_equal(s:DATE_INSERTED_AFTER_PRIORITY, self.data.get('existing_date_after_priority'))
+endfunction
+
+function! s:tc.test_insert_with_existing_date_and_priority()
+  let g:todo_existing_date = 'n'
+  call self.data.execute('call todo#txt#prepend_date()', 'existing_date_do_nothing')
+  call self.assert_equal(s:DATE_INSERTED_DO_NOTHING, self.data.get('existing_date_do_nothing'))
+  unlet g:todo_existing_date
+endfunction
+
 unlet s:tc