added base of event objects

openpype/pipeline/lib/__init__.py

@@ -1,3 +1,8 @@
+from .events import (
+    BaseEvent,
+    BeforeWorkfileSave
+)
+
 from .attribute_definitions import (
     AbtractAttrDef,
     UnknownDef,
@@ -9,6 +14,9 @@ from .attribute_definitions import (
 
 
 __all__ = (
+    "BaseEvent",
+    "BeforeWorkfileSave",
+
     "AbtractAttrDef",
     "UnknownDef",
     "NumberDef",

openpype/pipeline/lib/events.py

@@ -0,0 +1,38 @@
+"""Events holding data about specific event."""
+
+
+class BaseEvent:
+    """Base event object.
+
+    Can be used to anything because data are not much specific. Only required
+    argument is topic which defines why event is happening and may be used for
+    filtering.
+
+    Arg:
+        topic (str): Identifier of event.
+        data (Any): Data specific for event. Dictionary is recommended.
+    """
+    _data = {}
+
+    def __init__(self, topic, data=None):
+        self._topic = topic
+        if data is None:
+            data = {}
+        self._data = data
+
+    @property
+    def data(self):
+        return self._data
+
+    @property
+    def topic(self):
+        return self._topic
+
+
+class BeforeWorkfileSave(BaseEvent):
+    """Before workfile changes event data."""
+    def __init__(self, new_workfile, workdir):
+        super(BeforeWorkfileSave, self).__init__("before.workfile.save")
+
+        self.workfile_path = new_workfile
+        self.workdir_path = workdir