Fixed FormattingRules not being applied

src/myfasthtml/controls/DataGrid.py

@@ -220,7 +220,10 @@ class DataGrid(MultipleInstance):
     name, namespace = (conf.name, conf.namespace) if conf else ("No name", "__default__")
     self._settings = DatagridSettings(self, save_state=save_state, name=name, namespace=namespace)
     self._state = DatagridState(self, save_state=self._settings.save_state)
-    self._formatting_engine = FormattingEngine()
+    self._formatting_provider = DatagridMetadataProvider(self._parent)
+    self._formatting_engine = FormattingEngine(
+      rule_presets_provider=lambda: self._formatting_provider.rule_presets
+    )
     self._columns = None
     self.commands = Commands(self)
     
@@ -268,8 +271,7 @@ class DataGrid(MultipleInstance):
     # self._columns_manager.bind_command("SaveColumnDetails", self.commands.on_column_changed())
     
     if self._settings.enable_formatting:
-      provider = DatagridMetadataProvider(self._parent)
+      completion_engine = FormattingCompletionEngine(self._formatting_provider, self.get_table_name())
-      completion_engine = FormattingCompletionEngine(provider, self.get_table_name())
       editor_conf = DslEditorConf(engine_id=completion_engine.get_id())
       dsl = FormattingDSL()
       self._formatting_editor = DataGridFormattingEditor(self,

src/myfasthtml/controls/HierarchicalCanvasGraph.py

@@ -140,7 +140,7 @@ class HierarchicalCanvasGraph(MultipleInstance):
     self._query.bind_command("CancelQuery", self.commands.apply_filter())
     
     # Add Menu
-    self._menu = Menu(self, conf=MenuConf(["ResetView"]))
+    self._menu = Menu(self, conf=MenuConf(["ResetView"]), _id="-menu")
     
     logger.debug(f"HierarchicalCanvasGraph created with id={self._id}, "
                  f"nodes={len(conf.nodes)}, edges={len(conf.edges)}")

src/myfasthtml/core/formatting/dsl/completion/provider.py

@@ -15,12 +15,12 @@ from myfasthtml.core.formatting.dataclasses import RulePreset
 from myfasthtml.core.formatting.presets import (
   DEFAULT_FORMATTER_PRESETS, DEFAULT_STYLE_PRESETS, DEFAULT_RULE_PRESETS,
 )
-from myfasthtml.core.instances import SingleInstance, InstancesManager
+from myfasthtml.core.instances import UniqueInstance, InstancesManager
 
 logger = logging.getLogger(__name__)
 
 
-class DatagridMetadataProvider(SingleInstance, BaseMetadataProvider):
+class DatagridMetadataProvider(UniqueInstance, BaseMetadataProvider):
   """Concrete session-scoped metadata provider for DataGrid DSL engines.
 
   Implements BaseMetadataProvider by delegating live data queries to
@@ -36,8 +36,7 @@ class DatagridMetadataProvider(SingleInstance, BaseMetadataProvider):
       all_tables_formats: Global format rules applied to all tables.
   """
   
-  def __init__(self, parent=None, session: Optional[dict] = None,
+  def __init__(self, parent=None, session: Optional[dict] = None, _id: Optional[str] = None):
-               _id: Optional[str] = None):
     super().__init__(parent, session, _id)
     self.style_presets: dict = DEFAULT_STYLE_PRESETS.copy()
     self.formatter_presets: dict = DEFAULT_FORMATTER_PRESETS.copy()

src/myfasthtml/core/formatting/engine.py

@@ -31,7 +31,8 @@ class FormattingEngine:
       style_presets: dict = None,
       formatter_presets: dict = None,
       rule_presets: dict = None,
-      lookup_resolver: Callable[[str, str, str], dict] = None
+      lookup_resolver: Callable[[str, str, str], dict] = None,
+      rule_presets_provider: Callable[[], dict] = None,
   ):
     """
     Initialize the FormattingEngine.
@@ -41,11 +42,20 @@ class FormattingEngine:
         formatter_presets: Custom formatter presets. If None, uses defaults.
         rule_presets: Named rule presets (list of FormatRule dicts). If None, uses defaults.
         lookup_resolver: Function for resolving enum datagrid sources.
+        rule_presets_provider: Callable returning the current rule_presets dict.
+            When provided, takes precedence over rule_presets on every apply_format call.
+            Use this to keep the engine in sync with a shared provider.
     """
     self._condition_evaluator = ConditionEvaluator()
     self._style_resolver = StyleResolver(style_presets)
     self._formatter_resolver = FormatterResolver(formatter_presets, lookup_resolver)
     self._rule_presets = rule_presets if rule_presets is not None else DEFAULT_RULE_PRESETS
+    self._rule_presets_provider = rule_presets_provider
+
+  def _get_rule_presets(self) -> dict:
+    if self._rule_presets_provider is not None:
+      return self._rule_presets_provider()
+    return self._rule_presets
   
   def apply_format(
       self,
@@ -99,8 +109,8 @@ class FormattingEngine:
     """
     Replace any FormatRule that references a rule preset with the preset's rules.
 
-    A rule is a rule preset reference when its formatter has a preset name
+    A rule is a rule preset reference when its formatter or style has a preset name
-    that exists in rule_presets (and not in formatter_presets).
+    that exists in rule_presets.
 
     Args:
         rules: Original list of FormatRule
@@ -108,22 +118,26 @@ class FormattingEngine:
     Returns:
         Expanded list with preset references replaced by their FormatRules
     """
+    rule_presets = self._get_rule_presets()
     expanded = []
     for rule in rules:
-      preset_name = self._get_rule_preset_name(rule)
+      preset_name = self._get_rule_preset_name(rule, rule_presets)
       if preset_name:
-        expanded.extend(self._rule_presets[preset_name].rules)
+        expanded.extend(rule_presets[preset_name].rules)
       else:
         expanded.append(rule)
     return expanded
 
-  def _get_rule_preset_name(self, rule: FormatRule) -> str | None:
+  def _get_rule_preset_name(self, rule: FormatRule, rule_presets: dict) -> str | None:
-    """Return the preset name if the rule's formatter references a rule preset, else None."""
+    """Return the preset name if the rule references a rule preset via format() or style(), else None."""
-    if rule.formatter is None:
+    if rule.formatter is not None:
-      return None
+      preset = getattr(rule.formatter, "preset", None)
-    preset = getattr(rule.formatter, "preset", None)
+      if preset and preset in rule_presets:
-    if preset and preset in self._rule_presets:
+        return preset
-      return preset
+    if rule.style is not None:
+      preset = getattr(rule.style, "preset", None)
+      if preset and preset in rule_presets:
+        return preset
     return None
   
   def _get_matching_rules(

src/myfasthtml/core/instances.py

@@ -5,7 +5,7 @@ from typing import Optional, Literal
 from myfasthtml.controls.helpers import Ids
 from myfasthtml.core.commands import BoundCommand, Command
 from myfasthtml.core.constants import NO_DEFAULT_VALUE
-from myfasthtml.core.utils import pascal_to_snake, get_class, snake_to_pascal
+from myfasthtml.core.utils import pascal_to_snake, get_class, snake_to_pascal, debug_session
 
 VERBOSE_VERBOSE = False
 
@@ -36,7 +36,13 @@ class BaseInstance:
     session = args[1] if len(args) > 1 and isinstance(args[1], dict) else kwargs.get("session", None)
     _id = args[2] if len(args) > 2 and isinstance(args[2], str) else kwargs.get("_id", None)
     if VERBOSE_VERBOSE:
-      logger.debug(f"  parent={parent}, session={session}, _id={_id}")
+      logger.debug(f"  parent={parent}, session={debug_session(session)}, _id={_id}")
+    
+    # for UniqueInstance, the parent is always the ultimate root parent
+    if issubclass(cls, UniqueInstance):
+      parent = BaseInstance.get_ultimate_root_parent(parent)
+      if VERBOSE_VERBOSE:
+        logger.debug(f"  UniqueInstance detected. parent is set to ultimate root {parent=}")
     
     # Compute _id
     _id = cls.compute_id(_id, parent)
@@ -163,7 +169,7 @@ class BaseInstance:
   def compute_id(cls, _id: Optional[str], parent: Optional['BaseInstance']):
     if _id is None:
       prefix = cls.compute_prefix()
-      if issubclass(cls, SingleInstance):
+      if issubclass(cls, (SingleInstance, UniqueInstance)):
         _id = prefix
       else:
         _id = f"{prefix}-{str(uuid.uuid4())}"
@@ -174,6 +180,17 @@ class BaseInstance:
     
     return _id
   
+  @staticmethod
+  def get_ultimate_root_parent(instance):
+    if instance is None:
+      return None
+    
+    parent = instance
+    while True:
+      if parent.get_parent() is None:
+        return parent
+      parent = parent.get_parent()
+
 
 class SingleInstance(BaseInstance):
   """
@@ -200,7 +217,7 @@ class UniqueInstance(BaseInstance):
                _id: Optional[str] = None,
                auto_register: bool = True,
                on_init=None):
-    super().__init__(parent, session, _id, auto_register)
+    super().__init__(BaseInstance.get_ultimate_root_parent(parent), session, _id, auto_register)
     if on_init is not None:
       on_init()
 

tests/core/formatting/test_engine.py

@@ -350,3 +350,32 @@ class TestPresets:
 
         assert "background-color: purple" in css.css
         assert "color: yellow" in css.css
+
+    def test_i_can_expand_rule_preset_via_style(self):
+        """A rule preset referenced via style() must be expanded like via format().
+
+        Why: style("traffic_light") should expand the traffic_light rule preset
+        (which has conditional style rules) instead of looking up "traffic_light"
+        as a style preset name (where it doesn't exist).
+        """
+        engine = FormattingEngine()
+        rules = [FormatRule(style=Style(preset="traffic_light"))]
+
+        css, _ = engine.apply_format(rules, cell_value=-5)
+
+        assert css is not None
+        assert css.cls == "mf-formatting-error"
+
+    def test_i_can_expand_rule_preset_via_style_with_no_match(self):
+        """A rule preset via style() with a non-matching condition returns no style.
+
+        Why: traffic_light has style("error") only if value < 0.
+        A positive value should produce no style output.
+        """
+        engine = FormattingEngine()
+        rules = [FormatRule(style=Style(preset="traffic_light"))]
+
+        css, _ = engine.apply_format(rules, cell_value=10)
+
+        assert css is not None
+        assert css.cls == "mf-formatting-success"