Adding macros current_user_id & current_username (#2582)

* Adding macros current_user_id & current_username

* Addressing comments

superset/jinja_context.py

@@ -4,15 +4,16 @@
 from __future__ import print_function
 from __future__ import unicode_literals
 
+from datetime import datetime, timedelta
 import inspect
+import random
+import time
+import uuid
+
 from jinja2.sandbox import SandboxedEnvironment
-from flask import request
+from flask import request, g
 
-from datetime import datetime, timedelta
 from dateutil.relativedelta import relativedelta
-import time
-import uuid
-import random
 
 from superset import app
 
@@ -40,6 +41,18 @@ def url_param(param, default=None):
     return request.args.get(param, default)
 
 
+def current_user_id():
+    """The id of the user who is currently logged in"""
+    if g.user:
+        return g.user.id
+
+
+def current_username():
+    """The username of the user who is currently logged in"""
+    if g.user:
+        return g.user.username
+
+
 class BaseTemplateProcessor(object):
 
     """Base class for database-specific jinja context
@@ -67,6 +80,8 @@ def __init__(self, database=None, query=None, table=None, **kwargs):
             self.schema = table.schema
         self.context = {
             'url_param': url_param,
+            'current_user_id': current_user_id,
+            'current_username': current_username,
         }
         self.context.update(kwargs)
         self.context.update(BASE_CONTEXT)