giles
a0a0f5ebc2
Declarative relation registry via defrelation s-expressions with cardinality enforcement (one-to-one, one-to-many, many-to-many), registry-aware relate/unrelate/can-relate API endpoints, generic container-nav fragment, and relation-driven UI components. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
102 lines
2.7 KiB
Python
102 lines
2.7 KiB
Python
"""
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Relation registry — declarative entity relationship definitions.
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Relations are defined as s-expressions using ``defrelation`` and stored
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in a global registry. All services load the same definitions at startup
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via ``load_relation_registry()``.
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"""
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from __future__ import annotations
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from shared.sexp.types import RelationDef
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# ---------------------------------------------------------------------------
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# Registry
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# ---------------------------------------------------------------------------
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_RELATION_REGISTRY: dict[str, RelationDef] = {}
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def register_relation(defn: RelationDef) -> None:
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"""Add a RelationDef to the global registry."""
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_RELATION_REGISTRY[defn.name] = defn
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def get_relation(name: str) -> RelationDef | None:
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"""Look up a relation by name (e.g. ``"page->market"``)."""
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return _RELATION_REGISTRY.get(name)
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def relations_from(entity_type: str) -> list[RelationDef]:
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"""All relations where *entity_type* is the ``from`` side."""
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return [d for d in _RELATION_REGISTRY.values() if d.from_type == entity_type]
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def relations_to(entity_type: str) -> list[RelationDef]:
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"""All relations where *entity_type* is the ``to`` side."""
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return [d for d in _RELATION_REGISTRY.values() if d.to_type == entity_type]
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def all_relations() -> list[RelationDef]:
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"""Return all registered relations."""
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return list(_RELATION_REGISTRY.values())
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def clear_registry() -> None:
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"""Clear all registered relations (for testing)."""
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_RELATION_REGISTRY.clear()
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# ---------------------------------------------------------------------------
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# Built-in relation definitions (s-expression source)
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# ---------------------------------------------------------------------------
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_BUILTIN_RELATIONS = '''
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(begin
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(defrelation :page->market
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:from "page"
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:to "market"
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:cardinality :one-to-many
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:inverse :market->page
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:nav :submenu
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:nav-icon "fa fa-shopping-bag"
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:nav-label "markets")
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(defrelation :page->calendar
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:from "page"
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:to "calendar"
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:cardinality :one-to-many
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:inverse :calendar->page
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:nav :submenu
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:nav-icon "fa fa-calendar"
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:nav-label "calendars")
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(defrelation :post->calendar_entry
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:from "post"
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:to "calendar_entry"
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:cardinality :many-to-many
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:inverse :calendar_entry->post
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:nav :inline
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:nav-icon "fa fa-file-alt"
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:nav-label "events")
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(defrelation :page->menu_node
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:from "page"
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:to "menu_node"
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:cardinality :one-to-one
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:nav :hidden)
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)
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'''
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def load_relation_registry() -> None:
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"""Parse built-in defrelation s-expressions and populate the registry."""
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from shared.sexp.evaluator import evaluate
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from shared.sexp.parser import parse
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tree = parse(_BUILTIN_RELATIONS)
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evaluate(tree)
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