fix: implement safe retrieval of component classes from registry (#934)

src/django_components/component.py

@@ -1,4 +1,3 @@
-import inspect
 import types
 from collections import deque
 from contextlib import contextmanager
@@ -52,6 +51,7 @@ from django_components.dependencies import (
     cache_component_css_vars,
     cache_component_js,
     cache_component_js_vars,
+    comp_hash_mapping,
     postprocess_component_html,
     set_component_attrs_for_js_and_css,
 )
@@ -72,7 +72,7 @@ from django_components.slots import (
 )
 from django_components.template import cached_template
 from django_components.util.django_monkeypatch import is_template_cls_patched
-from django_components.util.misc import gen_id
+from django_components.util.misc import gen_id, hash_comp_cls
 from django_components.util.template_tag import TagAttr
 from django_components.util.validation import validate_typed_dict, validate_typed_tuple
 
@@ -499,7 +499,7 @@ class Component(
     However, there's a few differences from Django's Media class:
 
     1. Our Media class accepts various formats for the JS and CSS files: either a single file, a list,
-       or (CSS-only) a dictonary (See [`ComponentMediaInput`](../api#django_components.ComponentMediaInput)).
+       or (CSS-only) a dictionary (See [`ComponentMediaInput`](../api#django_components.ComponentMediaInput)).
     2. Individual JS / CSS files can be any of `str`, `bytes`, `Path`,
        [`SafeString`](https://dev.to/doridoro/django-safestring-afj), or a function
        (See [`ComponentMediaInputPath`](../api#django_components.ComponentMediaInputPath)).
@@ -556,7 +556,7 @@ class Component(
     # MISC
     # #####################################
 
-    _class_hash: ClassVar[int]
+    _class_hash: ClassVar[str]
 
     def __init__(
         self,
@@ -587,7 +587,8 @@ class Component(
         self._types: Optional[Union[Tuple[Any, Any, Any, Any, Any, Any], Literal[False]]] = None
 
     def __init_subclass__(cls, **kwargs: Any) -> None:
-        cls._class_hash = hash(inspect.getfile(cls) + cls.__name__)
+        cls._class_hash = hash_comp_cls(cls)
+        comp_hash_mapping[cls._class_hash] = cls
 
     @property
     def name(self) -> str:
@@ -627,7 +628,7 @@ class Component(
     @property
     def input(self) -> RenderInput[ArgsType, KwargsType, SlotsType]:
         """
-        Input holds the data (like arg, kwargs, slots) that were passsed to
+        Input holds the data (like arg, kwargs, slots) that were passed to
         the current execution of the `render` method.
         """
         if not len(self._render_stack):

src/django_components/dependencies.py

@@ -5,7 +5,6 @@ import json
 import re
 import sys
 from abc import ABC, abstractmethod
-from functools import lru_cache
 from hashlib import md5
 from typing import (
     TYPE_CHECKING,
@@ -36,7 +35,7 @@ from django.utils.safestring import SafeString, mark_safe
 from djc_core_html_parser import set_html_attributes
 
 from django_components.node import BaseNode
-from django_components.util.misc import get_import_path, is_nonempty_str
+from django_components.util.misc import is_nonempty_str
 
 if TYPE_CHECKING:
     from django_components.component import Component
@@ -103,13 +102,6 @@ else:
 
 
 # Convert Component class to something like `TableComp_a91d03`
-@lru_cache(None)
-def _hash_comp_cls(comp_cls: Type["Component"]) -> str:
-    full_name = get_import_path(comp_cls)
-    comp_cls_hash = md5(full_name.encode()).hexdigest()[0:6]
-    return comp_cls.__name__ + "_" + comp_cls_hash
-
-
 def _gen_cache_key(
     comp_cls_hash: str,
     script_type: ScriptType,
@@ -126,8 +118,7 @@ def _is_script_in_cache(
     script_type: ScriptType,
     input_hash: Optional[str],
 ) -> bool:
-    comp_cls_hash = _hash_comp_cls(comp_cls)
-    cache_key = _gen_cache_key(comp_cls_hash, script_type, input_hash)
+    cache_key = _gen_cache_key(comp_cls._class_hash, script_type, input_hash)
     return comp_media_cache.has(cache_key)
 
 
@@ -141,11 +132,10 @@ def _cache_script(
     Given a component and it's inlined JS or CSS, store the JS/CSS in a cache,
     so it can be retrieved via URL endpoint.
     """
-    comp_cls_hash = _hash_comp_cls(comp_cls)
 
     # E.g. `__components:MyButton:js:df7c6d10`
     if script_type in ("js", "css"):
-        cache_key = _gen_cache_key(comp_cls_hash, script_type, input_hash)
+        cache_key = _gen_cache_key(comp_cls._class_hash, script_type, input_hash)
     else:
         raise ValueError(f"Unexpected script_type '{script_type}'")
 
@@ -345,11 +335,7 @@ def _insert_component_comment(
     will be used by the ComponentDependencyMiddleware to collect all
     declared JS / CSS scripts.
     """
-    # Add components to the cache
-    comp_cls_hash = _hash_comp_cls(component_cls)
-    comp_hash_mapping[comp_cls_hash] = component_cls
-
-    data = f"{comp_cls_hash},{component_id},{js_input_hash or ''},{css_input_hash or ''}"
+    data = f"{component_cls._class_hash},{component_id},{js_input_hash or ''},{css_input_hash or ''}"
 
     # NOTE: It's important that we put the comment BEFORE the content, so we can
     # use the order of comments to evaluate components' instance JS code in the correct order.
@@ -868,8 +854,7 @@ def get_script_content(
     comp_cls: Type["Component"],
     input_hash: Optional[str],
 ) -> SafeString:
-    comp_cls_hash = _hash_comp_cls(comp_cls)
-    cache_key = _gen_cache_key(comp_cls_hash, script_type, input_hash)
+    cache_key = _gen_cache_key(comp_cls._class_hash, script_type, input_hash)
     script = comp_media_cache.get(cache_key)
 
     return script
@@ -897,12 +882,10 @@ def get_script_url(
     comp_cls: Type["Component"],
     input_hash: Optional[str],
 ) -> str:
-    comp_cls_hash = _hash_comp_cls(comp_cls)
-
     return reverse(
         CACHE_ENDPOINT_NAME,
         kwargs={
-            "comp_cls_hash": comp_cls_hash,
+            "comp_cls_hash": comp_cls._class_hash,
             "script_type": script_type,
             **({"input_hash": input_hash} if input_hash is not None else {}),
         },

src/django_components/util/misc.py

@@ -1,8 +1,12 @@
 import re
-from typing import Any, Callable, List, Optional, Type, TypeVar
+from hashlib import md5
+from typing import TYPE_CHECKING, Any, Callable, List, Optional, Type, TypeVar
 
 from django_components.util.nanoid import generate
 
+if TYPE_CHECKING:
+    from django_components.component import Component
+
 T = TypeVar("T")
 
 
@@ -71,3 +75,9 @@ def get_last_index(lst: List, key: Callable[[Any], bool]) -> Optional[int]:
 
 def is_nonempty_str(txt: Optional[str]) -> bool:
     return txt is not None and bool(txt.strip())
+
+
+def hash_comp_cls(comp_cls: Type["Component"]) -> str:
+    full_name = get_import_path(comp_cls)
+    comp_cls_hash = md5(full_name.encode()).hexdigest()[0:6]
+    return comp_cls.__name__ + "_" + comp_cls_hash