Change default carrier handling

Author: FBumann

flixopt/color_accessor.py

@@ -104,8 +104,8 @@ def setup(self, config: dict[str, str] | str | Path) -> ColorAccessor:
             config = fx_io.load_yaml(Path(config))
 
         for label, color in config.items():
-            # Check if it's a known carrier (in CONFIG.Carriers or lowercase convention)
-            if label in CONFIG.Carriers.defaults or label.islower():
+            # Check if it's a known carrier (has attribute on CONFIG.Carriers or lowercase)
+            if hasattr(CONFIG.Carriers, label) or label.islower():
                 self._carrier_colors[label] = color
             # Check if it's a component
             elif label in self._fs.components:

flixopt/config.py

@@ -174,17 +174,6 @@ def format(self, record):
                 'compute_infeasibilities': True,
             }
         ),
-        # Default carriers - colors from D3/Plotly palettes
-        'carriers': MappingProxyType(
-            {
-                'electricity': '#FECB52',  # Yellow - lightning
-                'heat': '#D62728',  # Red - warmth/fire
-                'gas': '#1F77B4',  # Blue - natural gas
-                'hydrogen': '#9467BD',  # Purple - clean/future
-                'fuel': '#8C564B',  # Brown - fossil/oil
-                'biomass': '#2CA02C',  # Green - organic/renewable
-            }
-        ),
     }
 )
 
@@ -608,13 +597,13 @@ class Carriers:
 
         from .carrier import Carrier
 
-        # Default carriers - created from _DEFAULTS
-        electricity: Carrier = Carrier('electricity', _DEFAULTS['carriers']['electricity'])
-        heat: Carrier = Carrier('heat', _DEFAULTS['carriers']['heat'])
-        gas: Carrier = Carrier('gas', _DEFAULTS['carriers']['gas'])
-        hydrogen: Carrier = Carrier('hydrogen', _DEFAULTS['carriers']['hydrogen'])
-        fuel: Carrier = Carrier('fuel', _DEFAULTS['carriers']['fuel'])
-        biomass: Carrier = Carrier('biomass', _DEFAULTS['carriers']['biomass'])
+        # Default carriers - colors from D3/Plotly palettes
+        electricity: Carrier = Carrier('electricity', '#FECB52')  # Yellow
+        heat: Carrier = Carrier('heat', '#D62728')  # Red
+        gas: Carrier = Carrier('gas', '#1F77B4')  # Blue
+        hydrogen: Carrier = Carrier('hydrogen', '#9467BD')  # Purple
+        fuel: Carrier = Carrier('fuel', '#8C564B')  # Brown
+        biomass: Carrier = Carrier('biomass', '#2CA02C')  # Green
 
     config_name: str = _DEFAULTS['config_name']
 
@@ -645,12 +634,12 @@ def reset(cls) -> None:
         # Reset Carriers to defaults
         from .carrier import Carrier
 
-        cls.Carriers.electricity = Carrier('electricity', _DEFAULTS['carriers']['electricity'])
-        cls.Carriers.heat = Carrier('heat', _DEFAULTS['carriers']['heat'])
-        cls.Carriers.gas = Carrier('gas', _DEFAULTS['carriers']['gas'])
-        cls.Carriers.hydrogen = Carrier('hydrogen', _DEFAULTS['carriers']['hydrogen'])
-        cls.Carriers.fuel = Carrier('fuel', _DEFAULTS['carriers']['fuel'])
-        cls.Carriers.biomass = Carrier('biomass', _DEFAULTS['carriers']['biomass'])
+        cls.Carriers.electricity = Carrier('electricity', '#FECB52')
+        cls.Carriers.heat = Carrier('heat', '#D62728')
+        cls.Carriers.gas = Carrier('gas', '#1F77B4')
+        cls.Carriers.hydrogen = Carrier('hydrogen', '#9467BD')
+        cls.Carriers.fuel = Carrier('fuel', '#8C564B')
+        cls.Carriers.biomass = Carrier('biomass', '#2CA02C')
 
         cls.config_name = _DEFAULTS['config_name']
 

flixopt/flow_system.py

@@ -855,6 +855,7 @@ def connect_and_transform(self):
             return
 
         self._connect_network()
+        self._register_missing_carriers()
         for element in chain(self.components.values(), self.effects.values(), self.buses.values()):
             element.transform_data()
 
@@ -863,6 +864,16 @@ def connect_and_transform(self):
 
         self._connected_and_transformed = True
 
+    def _register_missing_carriers(self) -> None:
+        """Auto-register carriers from CONFIG for buses that reference unregistered carriers."""
+        for bus in self.buses.values():
+            if bus.carrier and bus.carrier not in self._carriers:
+                # Try to get from CONFIG defaults
+                default_carrier = getattr(CONFIG.Carriers, bus.carrier, None)
+                if default_carrier is not None:
+                    self._carriers[bus.carrier] = default_carrier
+                    logger.debug(f"Auto-registered carrier '{bus.carrier}' from CONFIG")
+
     def add_elements(self, *elements: Element) -> None:
         """
         Add Components(Storages, Boilers, Heatpumps, ...), Buses or Effects to the FlowSystem
@@ -934,22 +945,17 @@ def add_carrier(self, carrier: Carrier) -> None:
     def get_carrier(self, name: str) -> Carrier | None:
         """Get a carrier by name.
 
-        Looks up carriers in this order:
-        1. Carriers registered on this FlowSystem via add_carrier()
-        2. Global carriers in CONFIG.Carriers
+        Returns carriers registered on this FlowSystem. After connect_and_transform(),
+        this includes carriers auto-registered from CONFIG.Carriers for buses that
+        reference them.
 
         Args:
             name: Carrier name (case-insensitive).
 
         Returns:
             Carrier object or None if not found.
         """
-        name_lower = name.lower()
-        # Check local registry first
-        if name_lower in self._carriers:
-            return self._carriers[name_lower]
-        # Fall back to CONFIG
-        return CONFIG.Carriers.get(name_lower)
+        return self._carriers.get(name.lower())
 
     @property
     def carriers(self) -> CarrierContainer: