1 files changed, 52 insertions, 39 deletions
diff --git a/src/argaze/DataFeatures.py b/src/argaze/DataFeatures.py
index cf7566a..ac3000c 100644
--- a/src/argaze/DataFeatures.py
+++ b/src/argaze/DataFeatures.py
@@ -7,7 +7,7 @@ __credits__ = []
 __copyright__ = "Copyright 2023, Ecole Nationale de l'Aviation Civile (ENAC)"
 __license__ = "BSD"
 
-from typing import TypeVar, Tuple
+from typing import TypeVar, Tuple, Any
 from dataclasses import dataclass, field
 import importlib
 from inspect import getmembers
@@ -103,13 +103,6 @@ class JsonEncoder(json.JSONEncoder):
 
             return public_dict
 
-class DataDictionary(dict):
-    """Enable dot.notation access to dictionary attributes"""
-
-    __getattr__ = dict.get
-    __setattr__ = dict.__setitem__
-    __delattr__ = dict.__delitem__
-
 class SharedObject():
     """Enable multiple threads sharing."""
 
@@ -180,37 +173,6 @@ class SharedObject():
         self._token = token
         self._lock.release()
 
-TimeStampedDataLoggerType = TypeVar('TimeStampedDataLogger', bound="TimeStampedDataLogger")
-# Type definition for type annotation convenience
-
-@dataclass
-class TimeStampedDataLogger():
-    """Abstract class to define what should provide a timestamped data logger."""
-
-    selector: str = field(default='data')
-    """Code evaluated to select data. Default 'data' string means that all incoming data will be written."""
-
-    @classmethod
-    def from_dict(self, logger_module_path: str, logger_parameters: dict) -> TimeStampedDataLoggerType:
-        """Load timestamped data logger from dictionary.
-
-        Parameters:
-            logger_module_path: class name to load
-            logger_parameters: attributes to load
-        """
-
-        # Prepend argaze.DataLog path when a single name is provided
-        if len(logger_module_path.split('.')) == 1:
-            logger_module_path = f'argaze.DataLog.{logger_module_path}'
-
-        logger_module = importlib.import_module(logger_module_path)
-        return logger_module.TimeStampedDataLogger(**logger_parameters)
-
-    def emit(self, timestamp: TimeStampType, data: DataDictionary):
-        """Emit timestamped data dictionary to a specific log destination."""
-
-        raise NotImplementedError('emit() method not implemented')
-
 class TimeStampedBuffer(collections.OrderedDict):
     """Ordered dictionary to handle timestamped data.
     ```
@@ -458,3 +420,54 @@ class TimeStampedBuffer(collections.OrderedDict):
             legend_patches.append(mpatches.Patch(color=color, label=name.upper()))
 
         return legend_patches
+
+class DataDictionary(dict):
+    """Enable dot.notation access to dictionary attributes"""
+
+    __getattr__ = dict.get
+    __setattr__ = dict.__setitem__
+    __delattr__ = dict.__delitem__
+
+# Import libraries that can be used in selector or formatter codes
+from argaze import GazeFeatures
+
+TimeStampedDataLoggerType = TypeVar('TimeStampedDataLogger', bound="TimeStampedDataLogger")
+# Type definition for type annotation convenience
+
+@dataclass
+class TimeStampedDataLogger():
+    """Abstract class to define what should provide a timestamped data logger."""
+
+    selector: str = field(default='True')
+    """Code evaluated to select data under a condition. Default 'True' string means that all incoming data will be accepted."""
+
+    formatter: str|list = field(default='timestamp, data')
+    """Code (or list of codes) evaluated to format timestamp and data to emit. Default 'timestamp, data' string means that all incoming timestamp and data values will be emitted."""
+
+    @classmethod
+    def from_dict(self, logger_module_path: str, logger_parameters: dict) -> TimeStampedDataLoggerType:
+        """Load timestamped data logger from dictionary.
+
+        Parameters:
+            logger_module_path: class name to load
+            logger_parameters: attributes to load
+        """
+
+        # Prepend argaze.DataLog path when a single name is provided
+        if len(logger_module_path.split('.')) == 1:
+            logger_module_path = f'argaze.DataLog.{logger_module_path}'
+
+        logger_module = importlib.import_module(logger_module_path)
+        return logger_module.TimeStampedDataLogger(**logger_parameters)
+
+    def __call__(self, timestamp: TimeStampType, data: DataDictionary) -> Any:
+        """Apply selector code to decide if data have to be logged, then apply formatter code before to call specific logger emit method."""
+
+        if eval(self.selector):
+
+            return self.emit(eval(self.formatter))
+
+    def emit(self, formatted_log: any):
+        """Emit formatted log to a destination."""
+
+        raise NotImplementedError('handle() method not implemented')