initial work on router compiler

idom_router/__init__.py

@@ -1,22 +1,20 @@
 # the version is statically loaded by setup.py
 __version__ = "0.0.1"
 
-from .router import (
-    Route,
-    RouterConstructor,
-    create_router,
-    link,
-    use_location,
-    use_params,
-    use_query,
-)
+from . import simple
+from .core import create_router, link, route, router_component, use_params, use_query
+from .types import Route, RouteCompiler, RouteResolver
 
-__all__ = [
+__all__ = (
     "create_router",
     "link",
+    "route",
+    "route",
     "Route",
-    "RouterConstructor",
-    "use_location",
+    "RouteCompiler",
+    "router_component",
+    "RouteResolver",
+    "simple",
     "use_params",
     "use_query",
-]
+)

idom_router/core.py

@@ -0,0 +1,134 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, replace
+from pathlib import Path
+from typing import Any, Callable, Iterator, Sequence, TypeVar
+from urllib.parse import parse_qs
+
+from idom import (
+    component,
+    create_context,
+    use_context,
+    use_location,
+    use_memo,
+    use_state,
+)
+from idom.backend.hooks import ConnectionContext, use_connection
+from idom.backend.types import Connection, Location
+from idom.core.types import VdomChild, VdomDict
+from idom.types import ComponentType, Context, Location
+from idom.web.module import export, module_from_file
+
+from idom_router.types import Route, RouteCompiler, Router, RouteResolver
+
+R = TypeVar("R", bound=Route)
+
+
+def route(path: str, element: Any | None, *routes: Route) -> Route:
+    return Route(path, element, routes)
+
+
+def create_router(compiler: RouteCompiler[R]) -> Router[R]:
+    """A decorator that turns a route compiler into a router"""
+
+    def wrapper(*routes: R) -> ComponentType:
+        return router_component(*routes, compiler=compiler)
+
+    return wrapper
+
+
+@component
+def router_component(
+    *routes: R,
+    compiler: RouteCompiler[R],
+) -> ComponentType | None:
+    old_conn = use_connection()
+    location, set_location = use_state(old_conn.location)
+
+    resolvers = use_memo(
+        lambda: tuple(map(compiler, _iter_routes(routes))),
+        dependencies=(compiler, hash(routes)),
+    )
+
+    match = use_memo(lambda: _match_route(resolvers, location))
+
+    if match is not None:
+        element, params = match
+        return ConnectionContext(
+            _route_state_context(element, value=_RouteState(set_location, params)),
+            value=Connection(old_conn.scope, location, old_conn.carrier),
+        )
+
+    return None
+
+
+@component
+def link(*children: VdomChild, to: str, **attributes: Any) -> VdomDict:
+    set_location = _use_route_state().set_location
+    attrs = {
+        **attributes,
+        "to": to,
+        "onClick": lambda event: set_location(Location(**event)),
+    }
+    return _link(attrs, *children)
+
+
+def use_params() -> dict[str, Any]:
+    """Get parameters from the currently matching route pattern"""
+    return _use_route_state().params
+
+
+def use_query(
+    keep_blank_values: bool = False,
+    strict_parsing: bool = False,
+    errors: str = "replace",
+    max_num_fields: int | None = None,
+    separator: str = "&",
+) -> dict[str, list[str]]:
+    """See :func:`urllib.parse.parse_qs` for parameter info."""
+    return parse_qs(
+        use_location().search[1:],
+        keep_blank_values=keep_blank_values,
+        strict_parsing=strict_parsing,
+        errors=errors,
+        max_num_fields=max_num_fields,
+        separator=separator,
+    )
+
+
+def _iter_routes(routes: Sequence[R]) -> Iterator[R]:
+    for parent in routes:
+        for child in _iter_routes(parent.routes):
+            yield replace(child, path=parent.path + child.path)  # type: ignore[misc]
+        yield parent
+
+
+def _match_route(
+    compiled_routes: Sequence[RouteResolver], location: Location
+) -> tuple[Any, dict[str, Any]] | None:
+    for resolver in compiled_routes:
+        match = resolver.resolve(location.pathname)
+        if match is not None:
+            return match
+    return None
+
+
+_link = export(
+    module_from_file("idom-router", file=Path(__file__).parent / "bundle.js"),
+    "Link",
+)
+
+
+@dataclass
+class _RouteState:
+    set_location: Callable[[Location], None]
+    params: dict[str, Any]
+
+
+def _use_route_state() -> _RouteState:
+    route_state = use_context(_route_state_context)
+    assert route_state is not None
+    return route_state
+
+
+_route_state_context: Context[_RouteState | None] = create_context(None)