4 files changed, 22 insertions, 6 deletions
diff --git a/grc/base/Block.py b/grc/base/Block.py
index b367e60e69..d2d7ebf426 100644
--- a/grc/base/Block.py
+++ b/grc/base/Block.py
@@ -18,13 +18,16 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 """
 
 from . import odict
-from . Constants import ADVANCED_PARAM_TAB, DEFAULT_PARAM_TAB
+from . Constants import ADVANCED_PARAM_TAB, DEFAULT_PARAM_TAB, BLOCK_FLAG_THROTTLE
 from Element import Element
 
 from Cheetah.Template import Template
 from UserDict import UserDict
 from itertools import imap
 
+from .. gui import Messages
+
+
 class TemplateArg(UserDict):
     """
     A cheetah template argument created from a param.
@@ -46,11 +49,16 @@ class TemplateArg(UserDict):
     def __call__(self):
         return self._param.get_evaluated()
 
-def _get_keys(lst): return [elem.get_key() for elem in lst]
+
+def _get_keys(lst):
+    return [elem.get_key() for elem in lst]
+
+
 def _get_elem(lst, key):
     try: return lst[_get_keys(lst).index(key)]
     except ValueError: raise ValueError, 'Key "%s" not found in %s.'%(key, _get_keys(lst))
 
+
 class Block(Element):
 
     def __init__(self, flow_graph, n):
@@ -73,6 +81,9 @@ class Block(Element):
         self._name = n.find('name')
         self._key = n.find('key')
         self._category = n.find('category') or ''
+        self._flags = n.find('flags') or ''
+        if n.find('throttle') and BLOCK_FLAG_THROTTLE not in self._flags:  # backwards-compatibility
+            self._flags += BLOCK_FLAG_THROTTLE
         self._grc_source = n.find('grc_source') or ''
         self._block_wrapper_path = n.find('block_wrapper_path')
         self._bussify_sink = n.find('bus_sink')
@@ -240,6 +251,9 @@ class Block(Element):
     def get_block_wrapper_path(self): return self._block_wrapper_path
     def get_comment(self): return self.get_param('comment').get_value()
 
+    def get_flags(self): return self._flags
+    def throttle(self): return "throttle" in self._flags
+
     ##############################################
     # Access Params
     ##############################################
diff --git a/grc/base/Constants.py b/grc/base/Constants.py
index efae0ecbb5..7949708d5b 100644
--- a/grc/base/Constants.py
+++ b/grc/base/Constants.py
@@ -38,3 +38,5 @@ DOMAIN_DTD = os.path.join(DATA_DIR, 'domain.dtd')
 GR_STREAM_DOMAIN = "gr_stream"
 GR_MESSAGE_DOMAIN = "gr_message"
 DEFAULT_DOMAIN = GR_STREAM_DOMAIN
+
+BLOCK_FLAG_THROTTLE = 'throttle'
diff --git a/grc/python/Block.py b/grc/python/Block.py
index 191b03b452..5d52e2bf3c 100644
--- a/grc/python/Block.py
+++ b/grc/python/Block.py
@@ -52,7 +52,6 @@ class Block(_Block, _GUIBlock):
         self._var_make = n.find('var_make')
         self._checks = n.findall('check')
         self._callbacks = n.findall('callback')
-        self._throttle = n.find('throttle') or ''
         self._bus_structure_source = n.find('bus_structure_source') or ''
         self._bus_structure_sink = n.find('bus_structure_sink') or ''
         #build the block
@@ -78,8 +77,6 @@ class Block(_Block, _GUIBlock):
 
         except: return ''
 
-    def throttle(self): return bool(self._throttle)
-
     def validate(self):
         """
         Validate this block.
diff --git a/grc/python/block.dtd b/grc/python/block.dtd
index 8cfd3dd392..145f4d8610 100644
--- a/grc/python/block.dtd
+++ b/grc/python/block.dtd
@@ -25,7 +25,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
     Top level element.
     A block contains a name, ...parameters list, and list of IO ports.
  -->
-<!ELEMENT block (name, key, category?, throttle?, import*, var_make?, var_value?, make, callback*, param_tab_order?, param*, bus_sink?, bus_source?, check*, sink*, source*, bus_structure_sink?, bus_structure_source?, doc?,  grc_source?)>
+<!ELEMENT block (name, key, category?, throttle?, flags?, import*, var_make?, var_value?,
+        make, callback*, param_tab_order?, param*, bus_sink?, bus_source?, check*,
+        sink*, source*, bus_structure_sink?, bus_structure_source?, doc?,  grc_source?)>
 <!--
     Sub level elements.
  -->
@@ -64,3 +66,4 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 <!ELEMENT callback (#PCDATA)>
 <!ELEMENT optional (#PCDATA)>
 <!ELEMENT throttle (#PCDATA)>
+<!ELEMENT flags (#PCDATA)>