implement the info transfer

src/finam/tools/connect_helper.py

@@ -3,10 +3,15 @@ import logging
 
 from finam.interfaces import ComponentStatus, Loggable
 
+from ..data.tools import Info
 from ..errors import FinamNoDataError
 from ..tools.log_helper import ErrorLogger
 
 
+class MissingInfoError(Exception):
+    """Internal error type for handling missing infos for transfer rules"""
+
+
 class InfoSource:
     def __init__(self, name, *fields):
         self.name = name
@@ -71,9 +76,6 @@ class ConnectHelper(Loggable):
         self._outputs = outputs
         self._cache = cache
 
-        self._in_info_rules = in_info_rules or {}
-        self._out_info_rules = in_info_rules or {}
-
         with ErrorLogger(self.logger):
             for name in pull_data or []:
                 if name not in self._inputs:
@@ -93,12 +95,34 @@ class ConnectHelper(Loggable):
             name: False for name, out in self.outputs.items() if out.needs_push
         }
 
+        self._in_info_rules = in_info_rules or {}
+        self._out_info_rules = out_info_rules or {}
         self._check_info_rules()
 
         self._in_info_cache = {}
         self._out_info_cache = {}
         self._out_data_cache = {}
 
+    def _apply_rules(self, rules):
+        info = Info(time=None, grid=None)
+        for rule in rules:
+            if isinstance(rule, FromInput):
+                in_info = self.in_infos[rule.name]
+                if in_info is None:
+                    raise MissingInfoError()
+                for field in rule.fields:
+                    info.__setattr__(field, in_info.__getattr__(field))
+            elif isinstance(rule, FromOutput):
+                out_info = self.out_infos[rule.name]
+                if out_info is None:
+                    raise MissingInfoError()
+                for field in rule.fields:
+                    info.__setattr__(field, out_info.__getattr__(field))
+            elif isinstance(rule, FromValue):
+                info.__setattr__(field, rule.value)
+
+        return info
+
     def _check_info_rules(self):
         for name, rules in self._in_info_rules.items():
             if name not in self._inputs:
@@ -216,6 +240,22 @@ class ConnectHelper(Loggable):
         push_infos = {k: v for k, v in push_infos.items() if self.out_infos[k] is None}
         push_data = {k: v for k, v in push_data.items() if not self.data_pushed[k]}
 
+        for name, rules in self._in_info_rules.items():
+            if self.in_infos[name] is None and name not in self._in_info_cache:
+                try:
+                    info = self._apply_rules(rules)
+                    exchange_infos[name] = info
+                except MissingInfoError:
+                    pass
+
+        for name, rules in self._out_info_rules.items():
+            if self.out_infos[name] is None and name not in self._out_info_cache:
+                try:
+                    info = self._apply_rules(rules)
+                    push_infos[name] = info
+                except MissingInfoError:
+                    pass
+
         if self._cache:
             self._in_info_cache.update(exchange_infos)
             self._out_info_cache.update(push_infos)