Notify user for messages logged at WARN or above by default. (#186)

Also adds a maktaba#log#SetNotificationLevel hook to override that level.

Author: dbarnett

autoload/maktaba/log.vim

@@ -21,6 +21,10 @@ endif
 
 let s:LEVELS = maktaba#log#LEVELS
 
+if !exists('s:notification_level')
+  let s:notification_level = s:LEVELS.WARN
+endif
+
 
 ""
 " @usage {level} {context} {message} [args...]
@@ -37,6 +41,9 @@ function! s:DoMessage(level, context, message, ...) abort
   endif
 
   call s:SendToHandlers([a:level, localtime(), a:context, l:message])
+  if s:notification_level isnot -1 && a:level >= s:notification_level
+    call s:NotifyMessage(printf('[%s] %s', a:context, l:message), a:level)
+  endif
 endfunction
 
 
@@ -85,6 +92,34 @@ function! s:SendToHandlers(logitem) abort
 endfunction
 
 
+function! s:NotifyMessage(message, level) abort
+  if a:level >= s:LEVELS.ERROR
+    call maktaba#error#Shout(a:message)
+  elseif a:level >= s:LEVELS.WARN
+    call maktaba#error#Warn(a:message)
+  else
+    echomsg a:message
+  endif
+endfunction
+
+
+""
+" Sets the minimum {level} of log messages that will trigger a user
+" notification, or -1 to disable notifications. By default, the user will be
+" notified after every message logged at WARN or higher.
+"
+" Notifications will be sent using @function(maktaba#error#Shout) for ERROR
+" and SEVERE messages, @function(maktaba#error#Warn) for WARN, and |:echomsg|
+" for INFO and DEBUG.
+" @throws BadValue
+function! maktaba#log#SetNotificationLevel(level) abort
+  call maktaba#ensure#IsTrue(
+      \ a:level is -1 || maktaba#value#IsIn(a:level, s:LEVELS.Values()),
+      \ 'Expected {level} to be maktaba#log#LEVELS value or -1')
+  let s:notification_level = a:level
+endfunction
+
+
 ""
 " Gets a string representing a single log {entry}.
 function! s:FormatLogEntry(entry) abort

doc/maktaba.txt

@@ -1226,6 +1226,16 @@ maktaba#list#RemoveAll({list}, {item})              *maktaba#list#RemoveAll()*
   Removes all instances of {item} from {list}. {list} is modified in place and
   returned for convenience.
 
+maktaba#log#SetNotificationLevel({level}) *maktaba#log#SetNotificationLevel()*
+  Sets the minimum {level} of log messages that will trigger a user
+  notification, or -1 to disable notifications. By default, the user will be
+  notified after every message logged at WARN or higher.
+
+  Notifications will be sent using |maktaba#error#Shout()| for ERROR and
+  SEVERE messages, |maktaba#error#Warn()| for WARN, and |:echomsg| for INFO
+  and DEBUG.
+  Throws ERROR(BadValue)
+
 maktaba#log#Logger({context})                           *maktaba#log#Logger()*
   Creates a |maktaba.Logger| interface for {context}.
 

vroom/log.vroom

@@ -27,8 +27,26 @@ the usual Debug, Info, Warn, Error, and Severe functions:
   :call g:vroom_logger.Debug('why')
   :call g:vroom_logger.Info('hello')
   :call g:vroom_logger.Warn('there')
+  ~ [VROOMFILE] there
   :call g:vroom_logger.Error('my')
+  ~ [VROOMFILE] my
   :call g:vroom_logger.Severe('friend')
+  ~ [VROOMFILE] friend
+
+By default, messages logged at WARN or above are also shown immediately to the
+user. Call maktaba#log#SetNotificationLevel to configure a different level.
+
+  :let g:LEVELS = maktaba#log#LEVELS
+  :call maktaba#log#SetNotificationLevel(g:LEVELS.SEVERE)
+  :call g:vroom_logger.Error('Threepio! Where could he be?!')
+  :call g:vroom_logger.Severe('Shut down all the garbage mashers!!')
+  ~ [VROOMFILE] Shut down all the garbage mashers!!
+
+Setting the display level to -1 disables printing these log messages completely.
+
+  :call maktaba#log#SetNotificationLevel(-1)
+  :call g:vroom_logger.Severe('Shut down all the garbage mashers!!')
+
 
 Each plugin gets a logger attached automatically for its context:
 
@@ -62,7 +80,9 @@ logged earlier...
   ~ Log message: WARN [-0-9T:]+ \[VROOMFILE\] there (regex)
   ~ Log message: ERROR [-0-9T:]+ \[VROOMFILE\] my (regex)
   ~ Log message: SEVERE [-0-9T:]+ \[VROOMFILE\] friend (regex)
-
+  ~ .* (regex)
+  ~ .* (regex)
+  ~ .* (regex)
   ~ Log message: DEBUG [-0-9T:]+ \[emptyplugin\] Hello from emptyplugin (regex)
 
 New messages are logged as they arrive.