From bd7abb58772ae1a61fd7eb44308a3a2f60432ad6 Mon Sep 17 00:00:00 2001
From: AKFish <akfish@gmail.com>
Date: Wed, 21 Aug 2013 23:01:40 +0800
Subject: [PATCH] Add update() method

---
 .gitignore             |  1 +
 github/Consts.py       | 49 ++++++++++++++++++++++++++++++++++++++++++
 github/GithubObject.py | 41 ++++++++++++++++++++++++++++++++++-
 3 files changed, 90 insertions(+), 1 deletion(-)
 create mode 100644 github/Consts.py

diff --git a/.gitignore b/.gitignore
index 3a7eff09..733d3ccd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,4 @@ GithubCredentials.py
 
 *.cfg
 *.bat
+*.py~
diff --git a/github/Consts.py b/github/Consts.py
new file mode 100644
index 00000000..2e551756
--- /dev/null
+++ b/github/Consts.py
@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+
+############################ Copyrights and license ############################
+#                                                                              #
+# Copyright 2013 AKFish <akfish@gmail.com>                                     #
+#                                                                              #
+# This file is part of PyGithub. http://jacquev6.github.com/PyGithub/          #
+#                                                                              #
+# PyGithub is free software: you can redistribute it and/or modify it under    #
+# the terms of the GNU Lesser General Public License as published by the Free  #
+# Software Foundation, either version 3 of the License, or (at your option)    #
+# any later version.                                                           #
+#                                                                              #
+# PyGithub 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 Lesser General Public License for more #
+# details.                                                                     #
+#                                                                              #
+# You should have received a copy of the GNU Lesser General Public License     #
+# along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
+#                                                                              #
+################################################################################
+
+# TODO: As of Thu Aug 21 22:40:13 (BJT) Chinese Standard Time 2013 
+# lots of consts in this project are explict
+# should realy round them up and reference them by consts
+
+################################################################################
+# Helper Function                                                              #
+################################################################################
+def get(dic, key):
+    if key in dic:
+        return key[dic]
+    return None
+
+
+################################################################################
+# Request Header                                                               #
+# (Case sensitive)                                                             #
+################################################################################
+REQ_IF_NONE_MATCH         = "If-None-Match"
+REQ_IF_MODIFIED_SINCE     = "If-Modified-Since" 
+
+################################################################################
+# Response Header                                                              #
+# (Lower Case)                                                                 #
+################################################################################
+RES_ETAG                  = "etag"
+RES_LAST_MODIFED          = "last-modified" 
diff --git a/github/GithubObject.py b/github/GithubObject.py
index f20873b9..ae71cf7c 100644
--- a/github/GithubObject.py
+++ b/github/GithubObject.py
@@ -32,6 +32,8 @@ import GithubException
 
 import pickle
 
+import Consts
+
 class _NotSetType:
     def __repr__(self):
         return "NotSet"
@@ -118,8 +120,45 @@ class GithubObject(object):
         '''
         with open(file_name, 'rb') as f:
             return pickle.load(f)
-        
 
+    @property
+    def etag(self):
+        '''
+        :type str
+        '''
+        return Consts.get(self._headers, Consts.RES_ETAG)
+
+    @property
+    def last_modified(self):
+        '''
+        :type str
+        '''
+        return Consts.get(self._headers, Consts.RES_LAST_MODIFED)
+    
+
+    def update(self):
+        '''
+        Check and update the object with conditional request
+        :rtype: Boolean value indicating whether the object is changed
+        '''
+        conditionalRequestHeader = dict()
+        if self.etag is not None:
+            conditionalRequestHeader[Consts.REQ_IF_NONE_MATCH] = self.etag
+        if self.last_modified is not None:
+            conditionalRequestHeader[Consts.REQ_IF_MODIFIED_SINCE] = self.last_modified
+
+        try:
+            headers, data = self._requester.requestJsonAndCheck(
+                "GET",
+                self._url,
+                conditionalRequestHeader,
+                None
+            )
+            self._storeAndUseAttributes(data)
+            self.__completed = True
+            return True
+        except: #GithubException.NotModifiedException:
+            return False
 
 class NonCompletableGithubObject(GithubObject):
     def _completeIfNeeded(self):