Provide the compilation object instead of just a part of it

The compilation result will be able to contain more than just
an execution graph in the near future so we should provide it
back instead of a subcomponent of the compilation result.

Breaking change: removes access to the execution graph property
and replaces it with a compilation property (that will contain
the execution graph and any other compilation related objects).

Change-Id: Ieba63f5ab3a59c38f4aa2a22d9caad412f8fa85d

taskflow/engines/action_engine/engine.py

@@ -71,15 +71,17 @@ class ActionEngine(base.EngineBase):
         self._change_state(states.SUSPENDING)
 
     @property
-    def execution_graph(self):
-        """The graph of nodes to be executed.
+    def compilation(self):
+        """The compilation result.
 
-        NOTE(harlowja): Only accessible after compilation has completed.
+        NOTE(harlowja): Only accessible after compilation has completed (None
+        will be returned when this property is accessed before compilation has
+        completed successfully).
         """
-        g = None
         if self._compiled:
-            g = self._compilation.execution_graph
-        return g
+            return self._compilation
+        else:
+            return None
 
     def run(self):
         with lock_utils.try_lock(self._lock) as was_locked:

taskflow/engines/action_engine/graph_analyzer.py

@@ -31,10 +31,6 @@ class GraphAnalyzer(object):
         self._graph = graph
         self._storage = storage
 
-    @property
-    def execution_graph(self):
-        return self._graph
-
     def get_next_nodes(self, node=None):
         if node is None:
             execute = self.browse_nodes_for_execute()

taskflow/tests/unit/test_action_engine.py

@@ -509,7 +509,7 @@ class EngineGraphFlowTest(utils.EngineTestBase):
 
         engine = self._make_engine(flow)
         engine.compile()
-        graph = engine.execution_graph
+        graph = engine.compilation.execution_graph
         self.assertIsInstance(graph, gr.DiGraph)
 
     def test_task_graph_property_for_one_task(self):
@@ -517,7 +517,7 @@ class EngineGraphFlowTest(utils.EngineTestBase):
 
         engine = self._make_engine(flow)
         engine.compile()
-        graph = engine.execution_graph
+        graph = engine.compilation.execution_graph
         self.assertIsInstance(graph, gr.DiGraph)