diff --git a/python/ycm/completers/all/identifier_completer.py b/python/ycm/completers/all/identifier_completer.py
index 196ff85a..aa3d812b 100644
--- a/python/ycm/completers/all/identifier_completer.py
+++ b/python/ycm/completers/all/identifier_completer.py
@@ -18,12 +18,10 @@
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import vim
 import ycm_core
 from collections import defaultdict
 from ycm.completers.general_completer import GeneralCompleter
-from ycm.completers.general import syntax_parse
-from ycm import vimsupport
+# from ycm.completers.general import syntax_parse
 from ycm import utils
 from ycm import server_responses
 
@@ -50,9 +48,9 @@ class IdentifierCompleter( GeneralCompleter ):
       request_data[ 'filetypes' ][ 0 ] )
 
 
-  def AddIdentifier( self, identifier ):
-    filetype = vim.eval( "&filetype" )
-    filepath = vim.eval( "expand('%:p')" )
+  def AddIdentifier( self, identifier, request_data ):
+    filetype = request_data[ 'filetypes' ][ 0 ]
+    filepath = request_data[ 'filepath' ]
 
     if not filetype or not filepath or not identifier:
       return
@@ -64,23 +62,20 @@ class IdentifierCompleter( GeneralCompleter ):
                                              filepath )
 
 
-  def AddPreviousIdentifier( self ):
-    self.AddIdentifier( _PreviousIdentifier( self.user_options[
-      'min_num_of_chars_for_completion' ] ) )
+  def AddPreviousIdentifier( self, request_data ):
+    self.AddIdentifier(
+      _PreviousIdentifier(
+        self.user_options[ 'min_num_of_chars_for_completion' ],
+        request_data ),
+      request_data )
 
 
-  def AddIdentifierUnderCursor( self ):
-    cursor_identifier = vim.eval( 'expand("<cword>")' )
+  def AddIdentifierUnderCursor( self, request_data ):
+    cursor_identifier = _GetCursorIdentifier( request_data )
     if not cursor_identifier:
       return
 
-    stripped_cursor_identifier = ''.join( ( x for x in
-                                            cursor_identifier if
-                                            utils.IsIdentifierChar( x ) ) )
-    if not stripped_cursor_identifier:
-      return
-
-    self.AddIdentifier( stripped_cursor_identifier )
+    self.AddIdentifier( cursor_identifier, request_data )
 
 
   def AddBufferIdentifiers( self, request_data ):
@@ -100,26 +95,22 @@ class IdentifierCompleter( GeneralCompleter ):
       collect_from_comments_and_strings )
 
 
-  def AddIdentifiersFromTagFiles( self ):
-    tag_files = vim.eval( 'tagfiles()' )
-    current_working_directory = os.getcwd()
+  def AddIdentifiersFromTagFiles( self, tag_files ):
     absolute_paths_to_tag_files = ycm_core.StringVec()
     for tag_file in tag_files:
-      absolute_tag_file = os.path.join( current_working_directory,
-                                        tag_file )
       try:
-        current_mtime = os.path.getmtime( absolute_tag_file )
+        current_mtime = os.path.getmtime( tag_file )
       except:
         continue
-      last_mtime = self.tags_file_last_mtime[ absolute_tag_file ]
+      last_mtime = self.tags_file_last_mtime[ tag_file ]
 
       # We don't want to repeatedly process the same file over and over; we only
       # process if it's changed since the last time we looked at it
       if current_mtime <= last_mtime:
         continue
 
-      self.tags_file_last_mtime[ absolute_tag_file ] = current_mtime
-      absolute_paths_to_tag_files.append( absolute_tag_file )
+      self.tags_file_last_mtime[ tag_file ] = current_mtime
+      absolute_paths_to_tag_files.append( tag_file )
 
     if not absolute_paths_to_tag_files:
       return
@@ -128,41 +119,37 @@ class IdentifierCompleter( GeneralCompleter ):
       absolute_paths_to_tag_files )
 
 
-  def AddIdentifiersFromSyntax( self ):
-    filetype = vim.eval( "&filetype" )
-    if filetype in self.filetypes_with_keywords_loaded:
-      return
+  # def AddIdentifiersFromSyntax( self ):
+  #   filetype = vim.eval( "&filetype" )
+  #   if filetype in self.filetypes_with_keywords_loaded:
+  #     return
 
-    self.filetypes_with_keywords_loaded.add( filetype )
+  #   self.filetypes_with_keywords_loaded.add( filetype )
 
-    keyword_set = syntax_parse.SyntaxKeywordsForCurrentBuffer()
-    keywords = ycm_core.StringVec()
-    for keyword in keyword_set:
-      keywords.append( keyword )
+  #   keyword_set = syntax_parse.SyntaxKeywordsForCurrentBuffer()
+  #   keywords = ycm_core.StringVec()
+  #   for keyword in keyword_set:
+  #     keywords.append( keyword )
 
-    filepath = SYNTAX_FILENAME + filetype
-    self.completer.AddIdentifiersToDatabase( keywords,
-                                             filetype,
-                                             filepath )
+  #   filepath = SYNTAX_FILENAME + filetype
+  #   self.completer.AddIdentifiersToDatabase( keywords,
+  #                                            filetype,
+  #                                            filepath )
 
 
   def OnFileReadyToParse( self, request_data ):
     self.AddBufferIdentifiers( request_data )
-
-    # TODO: make these work again
-    # if self.user_options[ 'collect_identifiers_from_tags_files' ]:
-    #   self.AddIdentifiersFromTagFiles()
-
-    # if self.user_options[ 'seed_identifiers_with_syntax' ]:
-    #   self.AddIdentifiersFromSyntax()
+    if 'tag_files' in request_data:
+      self.AddIdentifiersFromTagFiles( request_data[ 'tag_files' ] )
+    #self.AddIdentifiersFromSyntax()
 
 
-  def OnInsertLeave( self ):
-    self.AddIdentifierUnderCursor()
+  def OnInsertLeave( self, request_data ):
+    self.AddIdentifierUnderCursor( request_data )
 
 
-  def OnCurrentIdentifierFinished( self ):
-    self.AddPreviousIdentifier()
+  def OnCurrentIdentifierFinished( self, request_data ):
+    self.AddPreviousIdentifier( request_data )
 
 
   def CandidatesFromStoredRequest( self ):
@@ -177,10 +164,13 @@ class IdentifierCompleter( GeneralCompleter ):
     return [ server_responses.BuildCompletionData( x ) for x in completions ]
 
 
-def _PreviousIdentifier( min_num_completion_start_chars ):
-  line_num, column_num = vimsupport.CurrentLineAndColumn()
-  buffer = vim.current.buffer
-  line = buffer[ line_num ]
+def _PreviousIdentifier( min_num_completion_start_chars, request_data ):
+  line_num = request_data[ 'line_num' ]
+  column_num = request_data[ 'column_num' ]
+  filepath = request_data[ 'filepath' ]
+  contents_per_line = (
+    request_data[ 'file_data' ][ filepath ][ 'contents' ].split( '\n' ) )
+  line = contents_per_line[ line_num ]
 
   end_column = column_num
 
@@ -190,7 +180,7 @@ def _PreviousIdentifier( min_num_completion_start_chars ):
   # Look at the previous line if we reached the end of the current one
   if end_column == 0:
     try:
-      line = buffer[ line_num - 1]
+      line = contents_per_line[ line_num - 1 ]
     except:
       return ""
     end_column = len( line )
@@ -214,3 +204,40 @@ def _RemoveSmallCandidates( candidates, min_num_candidate_size_chars ):
 
   return [ x for x in candidates if len( x ) >= min_num_candidate_size_chars ]
 
+
+# This is meant to behave like 'expand("<cword")' in Vim, thus starting at the
+# cursor column and returning the "cursor word". If the cursor is not on a valid
+# character, it searches forward until a valid identifier is found.
+def _GetCursorIdentifier( request_data ):
+  def FindFirstValidChar( line, column ):
+    current_column = column
+    while not utils.IsIdentifierChar( line[ current_column ] ):
+      current_column += 1
+    return current_column
+
+
+  def FindIdentifierStart( line, valid_char_column ):
+    identifier_start = valid_char_column
+    while identifier_start > 0 and utils.IsIdentifierChar( line[
+      identifier_start - 1 ] ):
+      identifier_start -= 1
+    return identifier_start
+
+
+  def FindIdentifierEnd( line, valid_char_column ):
+    identifier_end = valid_char_column
+    while identifier_end < len( line ) - 1 and utils.IsIdentifierChar( line[
+      identifier_end + 1 ] ):
+      identifier_end += 1
+    return identifier_end + 1
+
+  column_num = request_data[ 'column_num' ]
+  line = request_data[ 'line_value' ]
+
+  try:
+    valid_char_column = FindFirstValidChar( line, column_num )
+    return line[ FindIdentifierStart( line, valid_char_column ) :
+                 FindIdentifierEnd( line, valid_char_column ) ]
+  except:
+    return ''
+
diff --git a/python/ycm/completers/all/tests/identifier_completer_test.py b/python/ycm/completers/all/tests/identifier_completer_test.py
new file mode 100644
index 00000000..532773cd
--- /dev/null
+++ b/python/ycm/completers/all/tests/identifier_completer_test.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2013  Strahinja Val Markovic  <val@markovic.io>
+#
+# This file is part of YouCompleteMe.
+#
+# YouCompleteMe is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# YouCompleteMe is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
+
+from nose.tools import eq_
+from ycm.completers.all import identifier_completer
+
+
+def GetCursorIdentifier_StartOfLine_test():
+  eq_( 'foo',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 0,
+           'line_value': 'foo'
+         } ) )
+
+  eq_( 'fooBar',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 0,
+           'line_value': 'fooBar'
+         } ) )
+
+
+def GetCursorIdentifier_EndOfLine_test():
+  eq_( 'foo',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 2,
+           'line_value': 'foo'
+         } ) )
+
+
+def GetCursorIdentifier_PastEndOfLine_test():
+  eq_( '',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 10,
+           'line_value': 'foo'
+         } ) )
+
+
+def GetCursorIdentifier_NegativeColumn_test():
+  eq_( '',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': -10,
+           'line_value': 'foo'
+         } ) )
+
+
+def GetCursorIdentifier_StartOfLine_StopsAtNonIdentifierChar_test():
+  eq_( 'foo',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 0,
+           'line_value': 'foo(goo)'
+         } ) )
+
+
+def GetCursorIdentifier_AtNonIdentifier_test():
+  eq_( 'goo',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 3,
+           'line_value': 'foo(goo)'
+         } ) )
+
+
+def GetCursorIdentifier_WalksForwardForIdentifier_test():
+  eq_( 'foo',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 0,
+           'line_value': '       foo'
+         } ) )
+
+
+def GetCursorIdentifier_FindsNothingForward_test():
+  eq_( '',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 4,
+           'line_value': 'foo   ()***()'
+         } ) )
+
+
+def GetCursorIdentifier_SingleCharIdentifier_test():
+  eq_( 'f',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 0,
+           'line_value': '    f    '
+         } ) )
+
+
+def GetCursorIdentifier_StartsInMiddleOfIdentifier_test():
+  eq_( 'foobar',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 3,
+           'line_value': 'foobar'
+         } ) )
+
+
+def GetCursorIdentifier_LineEmpty_test():
+  eq_( '',
+       identifier_completer._GetCursorIdentifier(
+         {
+           'column_num': 11,
+           'line_value': ''
+         } ) )
diff --git a/python/ycm/completers/completer.py b/python/ycm/completers/completer.py
index ec5732e5..321c8e1c 100644
--- a/python/ycm/completers/completer.py
+++ b/python/ycm/completers/completer.py
@@ -265,19 +265,19 @@ class Completer( object ):
     pass
 
 
-  def OnBufferVisit( self ):
+  def OnBufferVisit( self, request_data ):
     pass
 
 
-  def OnBufferUnload( self, deleted_buffer_file ):
+  def OnBufferUnload( self, request_data ):
     pass
 
 
-  def OnInsertLeave( self ):
+  def OnInsertLeave( self, request_data ):
     pass
 
 
-  def OnVimLeave( self ):
+  def OnVimLeave( self, request_data ):
     pass
 
 
@@ -285,7 +285,7 @@ class Completer( object ):
     raise NotImplementedError( NO_USER_COMMANDS )
 
 
-  def OnCurrentIdentifierFinished( self ):
+  def OnCurrentIdentifierFinished( self, request_data ):
     pass
 
 
diff --git a/python/ycm/completers/cpp/clang_completer.py b/python/ycm/completers/cpp/clang_completer.py
index 73e90eef..98d9f5a0 100644
--- a/python/ycm/completers/cpp/clang_completer.py
+++ b/python/ycm/completers/cpp/clang_completer.py
@@ -245,8 +245,8 @@ class ClangCompleter( Completer ):
     self.extra_parse_desired = False
 
 
-  def OnBufferUnload( self, deleted_buffer_file ):
-    self.completer.DeleteCachesForFileAsync( deleted_buffer_file )
+  def OnBufferUnload( self, request_data ):
+    self.completer.DeleteCachesForFileAsync( request_data[ 'unloaded_buffer' ] )
 
 
   def DiagnosticsForCurrentFileReady( self ):
@@ -271,7 +271,7 @@ class ClangCompleter( Completer ):
       self.parse_future = None
 
       if self.extra_parse_desired:
-        self.OnFileReadyToParse()
+        self.OnFileReadyToParse( request_data )
 
     return self.last_prepared_diagnostics
 
diff --git a/python/ycm/completers/general/general_completer_store.py b/python/ycm/completers/general/general_completer_store.py
index fcfe5f76..3269bc97 100644
--- a/python/ycm/completers/general/general_completer_store.py
+++ b/python/ycm/completers/general/general_completer_store.py
@@ -100,29 +100,29 @@ class GeneralCompleterStore( Completer ):
       completer.OnFileReadyToParse( request_data )
 
 
-  def OnBufferVisit( self ):
+  def OnBufferVisit( self, request_data ):
     for completer in self._all_completers:
-      completer.OnBufferVisit()
+      completer.OnBufferVisit( request_data )
 
 
-  def OnBufferUnload( self, deleted_buffer_file ):
+  def OnBufferUnload( self, request_data ):
     for completer in self._all_completers:
-      completer.OnBufferUnload( deleted_buffer_file )
+      completer.OnBufferUnload( request_data )
 
 
-  def OnInsertLeave( self ):
+  def OnInsertLeave( self, request_data ):
     for completer in self._all_completers:
-      completer.OnInsertLeave()
+      completer.OnInsertLeave( request_data )
 
 
-  def OnVimLeave( self ):
+  def OnVimLeave( self, request_data ):
     for completer in self._all_completers:
-      completer.OnVimLeave()
+      completer.OnVimLeave( request_data )
 
 
-  def OnCurrentIdentifierFinished( self ):
+  def OnCurrentIdentifierFinished( self, request_data ):
     for completer in self._all_completers:
-      completer.OnCurrentIdentifierFinished()
+      completer.OnCurrentIdentifierFinished( request_data )
 
 
   def GettingCompletions( self ):
diff --git a/python/ycm/completers/general/ultisnips_completer.py b/python/ycm/completers/general/ultisnips_completer.py
index d16b174f..a66c6fdc 100644
--- a/python/ycm/completers/general/ultisnips_completer.py
+++ b/python/ycm/completers/general/ultisnips_completer.py
@@ -51,7 +51,9 @@ class UltiSnipsCompleter( GeneralCompleter ):
     return self._filtered_candidates if self._filtered_candidates else []
 
 
-  def OnBufferVisit( self ):
+  def OnBufferVisit( self, request_data ):
+    # TODO: _GetCandidates should be called on the client and it should send
+    # the snippets to the server
     self._candidates = _GetCandidates()
 
 
diff --git a/python/ycm/youcompleteme.py b/python/ycm/youcompleteme.py
index 1e8d8efb..a7f8e276 100644
--- a/python/ycm/youcompleteme.py
+++ b/python/ycm/youcompleteme.py
@@ -31,8 +31,27 @@ from ycm.completers.general.general_completer_store import GeneralCompleterStore
 
 
 # TODO: Put the Request classes in separate files
-class CompletionRequest( object ):
+class BaseRequest( object ):
+  def __init__( self ):
+    pass
+
+
+  def Start( self ):
+    pass
+
+
+  def Done( self ):
+    return True
+
+
+  def Response( self ):
+    return {}
+
+
+class CompletionRequest( BaseRequest ):
   def __init__( self, ycm_state ):
+    super( CompletionRequest, self ).__init__()
+
     self._completion_start_column = base.CompletionStartColumn()
     self._ycm_state = ycm_state
     self._request_data = _BuildRequestData( self._completion_start_column )
@@ -70,7 +89,7 @@ class CompletionRequest( object ):
 
 
 
-class CommandRequest( object ):
+class CommandRequest( BaseRequest ):
   class ServerResponse( object ):
     def __init__( self ):
       pass
@@ -79,6 +98,8 @@ class CommandRequest( object ):
       return True
 
   def __init__( self, ycm_state, arguments, completer_target = None ):
+    super( CommandRequest, self ).__init__()
+
     if not completer_target:
       completer_target = 'filetpe_default'
 
@@ -95,9 +116,6 @@ class CommandRequest( object ):
     self._completer.OnUserCommand( self._arguments,
                                    _BuildRequestData() )
 
-  def Done( self ):
-    return True
-
 
   def Response( self ):
     # TODO: Call vimsupport.JumpToLocation if the user called a GoTo command...
@@ -117,6 +135,31 @@ class CommandRequest( object ):
     return self.ServerResponse()
 
 
+class EventNotification( BaseRequest ):
+  def __init__( self, event_name, ycm_state, extra_data = None ):
+    super( EventNotification, self ).__init__()
+
+    self._ycm_state = ycm_state
+    self._event_name = event_name
+    self._request_data = _BuildRequestData()
+    if extra_data:
+      self._request_data.update( extra_data )
+
+
+  def Start( self ):
+    getattr( self._ycm_state.GetGeneralCompleter(),
+             'On' + self._event_name )( self._request_data )
+
+    if self._ycm_state.FiletypeCompletionUsable():
+      getattr( self._ycm_state.GetFiletypeCompleter(),
+               'On' + self._event_name )( self._request_data )
+
+
+
+def SendEventNotificationAsync( event_name, ycm_state, extra_data = None ):
+  event = EventNotification( event_name, ycm_state, extra_data )
+  event.Start()
+
 
 class YouCompleteMe( object ):
   def __init__( self, user_options ):
@@ -235,38 +278,36 @@ class YouCompleteMe( object ):
 
 
   def OnFileReadyToParse( self ):
-    self._gencomp.OnFileReadyToParse( _BuildRequestData() )
+    extra_data = {}
+    if self._user_options[ 'collect_identifiers_from_tags_files' ]:
+      extra_data[ 'tag_files' ] = _GetTagFiles()
 
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnFileReadyToParse( _BuildRequestData() )
+    # TODO: make this work again
+    # if self._user_options[ 'seed_identifiers_with_syntax' ]:
+
+    SendEventNotificationAsync( 'FileReadyToParse', self, extra_data )
 
 
   def OnBufferUnload( self, deleted_buffer_file ):
-    self._gencomp.OnBufferUnload( deleted_buffer_file )
-
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnBufferUnload( deleted_buffer_file )
+    SendEventNotificationAsync( 'BufferUnload',
+                                self,
+                                { 'unloaded_buffer': deleted_buffer_file } )
 
 
   def OnBufferVisit( self ):
-    self._gencomp.OnBufferVisit()
-
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnBufferVisit()
+    SendEventNotificationAsync( 'BufferVisit', self )
 
 
   def OnInsertLeave( self ):
-    self._gencomp.OnInsertLeave()
-
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnInsertLeave()
+    SendEventNotificationAsync( 'InsertLeave', self )
 
 
   def OnVimLeave( self ):
-    self._gencomp.OnVimLeave()
+    SendEventNotificationAsync( 'VimLeave', self )
 
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnVimLeave()
+
+  def OnCurrentIdentifierFinished( self ):
+    SendEventNotificationAsync( 'CurrentIdentifierFinished', self )
 
 
   def DiagnosticsForCurrentFileReady( self ):
@@ -292,13 +333,6 @@ class YouCompleteMe( object ):
     return False
 
 
-  def OnCurrentIdentifierFinished( self ):
-    self._gencomp.OnCurrentIdentifierFinished()
-
-    if self.FiletypeCompletionUsable():
-      self.GetFiletypeCompleter().OnCurrentIdentifierFinished()
-
-
   def DebugInfo( self ):
     completers = set( self._filetype_completers.values() )
     completers.add( self._gencomp )
@@ -370,3 +404,8 @@ def _ConvertCompletionDataToVimData( completion_data ):
     vim_data[ 'info' ] = completion_data[ 'detailed_info' ]
 
   return vim_data
+
+def _GetTagFiles():
+  tag_files = vim.eval( 'tagfiles()' )
+  current_working_directory = os.getcwd()
+  return [ os.path.join( current_working_directory, x ) for x in tag_files ]