* Allow listening to context var updates via Env.context_var_updated …

…hook

* RuntimeContext.context_entered and RuntimeContext.context_exited event handlers now get context_vars instead of rather pointless runtime_context reference

* Bump version: 1.0.0 → 1.1.0

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 1.0.0
+current_version = 1.1.0
 commit = true
 tag = false
 

runtime_context/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '1.0.0'
+__version__ = '1.1.0'
 
 from .env2 import runtime_context_env
 from .runtime_context import RuntimeContext

runtime_context/env2.py

@@ -2,6 +2,8 @@
 @runtime_context_env is a decorator for your custom Env class which may want to have its attributes overridden by
 context variables.
 """
+from hookery import HookRegistry
+
 from .runtime_context import RuntimeContext
 
 
@@ -11,10 +13,20 @@ class EnvBase:
         'set',
         'runtime_context',
         'is_context_var',
+        '_hooks',
+        'context_var_updated',
+        '_handle_runtime_context_entered',
+        '_handle_runtime_context_exited',
     )
 
     runtime_context = None  # type: RuntimeContext
 
+    def __init__(self):
+        self._hooks = HookRegistry()
+        self.context_var_updated = self._hooks.register_event('context_var_updated')
+        self.runtime_context.context_entered(self._handle_runtime_context_entered)
+        self.runtime_context.context_exited(self._handle_runtime_context_exited)
+
     def is_context_var(self, name):
         """
         Context variable is something that can be customised per context.
@@ -44,6 +56,7 @@ def __setattr__(self, name, value):
             object.__setattr__(self, name, value)
         elif self.is_context_var(name):
             self.runtime_context.set(name, value)
+            self.context_var_updated.trigger(name=name)
         else:
             object.__setattr__(self, name, value)
 
@@ -57,6 +70,14 @@ def set(self, name, value):
             raise AttributeError(name)
         setattr(self, name, value)
 
+    def _handle_runtime_context_entered(self, context_vars):
+        for k in context_vars.keys():
+            self.context_var_updated.trigger(name=k)
+
+    def _handle_runtime_context_exited(self, context_vars):
+        for k in context_vars.keys():
+            self.context_var_updated.trigger(name=k)
+
 
 def runtime_context_env(env_cls):
     return type(env_cls.__name__, (env_cls, EnvBase), {

runtime_context/runtime_context.py

@@ -13,12 +13,13 @@ def __init__(self, runtime_context, **context_vars):
 
     def __enter__(self):
         self.runtime_context._stack.append(self.context_vars)
-        self.runtime_context.context_entered.trigger(context=self.runtime_context)
+        self.runtime_context.context_entered.trigger(context_vars=self.context_vars)
         return self.runtime_context
 
     def __exit__(self, exc_type, exc_val, exc_tb):
-        self.runtime_context._stack.pop()
-        self.runtime_context.context_exited.trigger(context=self.runtime_context)
+        popped = self.runtime_context._stack.pop()
+        assert popped is self.context_vars
+        self.runtime_context.context_exited.trigger(context_vars=self.context_vars)
 
 
 class RuntimeContext:

tests/test_env2.py

@@ -10,6 +10,7 @@ class App:
         y = 1
 
         def __init__(self):
+            super().__init__()
             self.z = 2
 
     app = App()
@@ -92,3 +93,43 @@ def __init__(self):
 
     assert app.get('x') == 0
     assert app.get('y') == 1
+
+
+def test_change_hooks():
+    @runtime_context_env
+    class App:
+        config_file = 'config.json'
+        x = None
+
+        def __init__(self):
+            super().__init__()
+            self.times_reloaded = 0
+
+        def reload_config(self):
+            self.times_reloaded += 1
+
+    app = App()
+
+    @app.context_var_updated
+    def reload_local_config(name):
+        if name == 'config_file':
+            app.reload_config()
+
+    with app():
+        with app(x=1):
+            assert app.times_reloaded == 0
+            with app(config_file='config.yaml'):
+                assert app.times_reloaded == 1
+
+            assert app.times_reloaded == 2
+
+        assert app.times_reloaded == 2
+
+        app.config_file = 'config.txt'
+        assert app.times_reloaded == 3
+
+        with app():
+            assert app.times_reloaded == 3
+        assert app.times_reloaded == 3
+
+    assert app.times_reloaded == 4

tests/test_runtime_context.py

@@ -1,14 +1,6 @@
 import pytest
 
 
-def test_rc_fixture(rc):
-    import runtime_context
-
-    assert isinstance(rc, runtime_context.RuntimeContext)
-    assert len(rc._stack) == 1
-    assert rc._stack[-1] == {}
-
-
 def test_rc_basics(rc):
     """
     Basics are: