"""
Provide rendering utilities using `Jinja2 <https://jinja.palletsprojects.com>`_.
"""
from __future__ import annotations
import datetime
from collections import defaultdict
from threading import Lock
from typing import Callable, Any, cast, TYPE_CHECKING, TypeAlias, final, Awaitable
import aiofiles
from aiofiles import os as aiofiles_os
from jinja2 import (
Environment as Jinja2Environment,
select_autoescape,
FileSystemLoader,
pass_context,
Template,
)
from jinja2.runtime import StrictUndefined, Context, DebugUndefined
from typing_extensions import override
from betty import model
from betty.asyncio import wait_to_thread
from betty.html import CssProvider, JsProvider
from betty.jinja2.filter import FILTERS
from betty.jinja2.test import TESTS
from betty.job import Context as JobContext
from betty.locale.localizer import Localizer
from betty.locale.localizer import DEFAULT_LOCALIZER
from betty.locale.date import Date
from betty.render import Renderer
from betty.serde.dump import Dumpable, DumpMapping, VoidableDump, Dump
from betty.typing import Void
from collections.abc import (
Mapping,
)
if TYPE_CHECKING:
from betty.model import Entity
from betty.project.extension import Extension
from betty.project import ProjectConfiguration, Project
from betty.ancestry import Citation
from pathlib import Path
from collections.abc import (
MutableMapping,
Iterator,
Sequence,
MutableSequence,
)
[docs]
def context_project(context: Context) -> Project:
"""
Get the current project from the Jinja2 context.
"""
return cast(Environment, context.environment).project
[docs]
def context_job_context(context: Context) -> JobContext | None:
"""
Get the current job context from the Jinja2 context.
"""
job_context = context.resolve_or_missing("job_context")
return job_context if isinstance(job_context, JobContext) else None
[docs]
def context_localizer(context: Context) -> Localizer:
"""
Get the current localizer from the Jinja2 context.
"""
localizer = context.resolve_or_missing("localizer")
if isinstance(localizer, Localizer):
return localizer
raise RuntimeError(
"No `localizer` context variable exists in this Jinja2 template."
)
class _Citer:
__slots__ = "_lock", "_cited"
def __init__(self):
self._lock = Lock()
self._cited: MutableSequence[Citation] = []
def __iter__(self) -> enumerate[Citation]:
return enumerate(self._cited, 1)
def __len__(self) -> int:
return len(self._cited)
def cite(self, citation: Citation) -> int:
with self._lock:
if citation not in self._cited:
self._cited.append(citation)
return self._cited.index(citation) + 1
class _Breadcrumb(Dumpable):
def __init__(self, label: str, url: str):
self._label = label
self._url = url
@override
def dump(self) -> DumpMapping[Dump]:
return {
"@type": "ListItem",
"name": self._label,
"item": self._url,
}
class _Breadcrumbs(Dumpable):
def __init__(self):
self._breadcrumbs: MutableSequence[_Breadcrumb] = []
def append(self, label: str, url: str) -> None:
self._breadcrumbs.append(_Breadcrumb(label, url))
@override
def dump(self) -> VoidableDump:
if not self._breadcrumbs:
return Void
return {
"@context": "https://schema.org",
"@type": "BreadcrumbList",
"itemListElement": [
{
"position": position,
**breadcrumb.dump(),
}
for position, breadcrumb in enumerate(self._breadcrumbs, 1)
],
}
[docs]
class EntityContexts:
"""
Track the current entity contexts.
To allow templates to respond to their environment, this class allows
our templates to set and get one entity per entity type for the current context.
Use cases include rendering an entity label as plain text if the template is in
that entity's context, but as a hyperlink if the template is not in the entity's
context.
"""
[docs]
def __init__(self, *entities: Entity) -> None:
self._contexts: MutableMapping[type[Entity], Entity | None] = defaultdict(
lambda: None
)
for entity in entities:
self._contexts[entity.type] = entity
def __getitem__(
self, entity_type_or_type_name: type[Entity] | str
) -> Entity | None:
if isinstance(entity_type_or_type_name, str):
entity_type = wait_to_thread(
model.ENTITY_TYPE_REPOSITORY.get(entity_type_or_type_name)
)
else:
entity_type = entity_type_or_type_name
return self._contexts[entity_type]
def __call__(self, *entities: Entity) -> EntityContexts:
"""
Create a new context with the given entities.
"""
updated_contexts = EntityContexts(
*(entity for entity in self._contexts.values() if entity is not None)
)
for entity in entities:
updated_contexts._contexts[entity.type] = entity
return updated_contexts
Globals: TypeAlias = Mapping[str, Any]
Filters: TypeAlias = Mapping[str, Callable[..., Any]]
Tests: TypeAlias = Mapping[str, Callable[..., bool]]
ContextVars: TypeAlias = Mapping[str, Any]
[docs]
class Jinja2Provider:
"""
Integrate an :py:class:`betty.project.extension.Extension` with the Jinja2 API.
"""
@property
def globals(self) -> Globals:
"""
Jinja2 globals provided by this extension.
Keys are the globals' names, and values are the globals' values.
"""
return {}
@property
def filters(self) -> Filters:
"""
Jinja2 filters provided by this extension.
Keys are filter names, and values are the filters themselves.
"""
return {}
@property
def tests(self) -> Tests:
"""
Jinja2 tests provided by this extension.
Keys are test names, and values are the tests themselves.
"""
return {}
[docs]
def new_context_vars(self) -> ContextVars:
"""
Create new variables for a new :py:class:`jinja2.runtime.Context`.
Keys are the variable names, and values are variable values.
"""
return {}
[docs]
class Environment(Jinja2Environment):
"""
Betty's Jinja2 environment.
"""
globals: dict[str, Any]
filters: dict[str, Callable[..., Any]]
tests: dict[str, Callable[..., bool | Awaitable[bool]]] # type: ignore[assignment]
[docs]
def __init__(self, project: Project):
template_directory_paths = [
str(path / "templates") for path in project.assets.assets_directory_paths
]
super().__init__(
loader=FileSystemLoader(template_directory_paths),
auto_reload=project.configuration.debug,
enable_async=True,
undefined=(
DebugUndefined if project.configuration.debug else StrictUndefined
),
autoescape=select_autoescape(["html.j2"]),
trim_blocks=True,
lstrip_blocks=True,
extensions=[
"jinja2.ext.do",
"jinja2.ext.i18n",
],
)
self._context_class: type[Context] | None = None
self._project = project
if project.configuration.debug:
self.add_extension("jinja2.ext.debug")
self._init_i18n()
self._init_globals()
self.filters.update(FILTERS)
self.tests.update(TESTS)
self._init_extensions()
@property
def project(self) -> Project:
"""
The current project.
"""
return self._project
def _init_i18n(self) -> None:
self.install_gettext_callables( # type: ignore[attr-defined]
gettext=self._gettext,
ngettext=self._ngettext,
pgettext=self._pgettext,
npgettext=self._npgettext,
)
self.policies["ext.i18n.trimmed"] = True
@override
@property
def context_class(self) -> type[Context]: # type: ignore[override]
if self._context_class is None:
jinja2_providers: Sequence[Jinja2Provider & Extension] = [
extension
for extension in self.project.extensions.flatten()
if isinstance(extension, Jinja2Provider)
]
class _Context(Context):
def __init__(
self,
environment: Environment,
parent: dict[str, Any],
name: str | None,
blocks: dict[str, Callable[[Context], Iterator[str]]],
globals: MutableMapping[str, Any] | None = None, # noqa A002
):
if "citer" not in parent:
parent["citer"] = _Citer()
if "breadcrumbs" not in parent:
parent["breadcrumbs"] = _Breadcrumbs()
for jinja2_provider in jinja2_providers:
for key, value in jinja2_provider.new_context_vars().items():
if key not in parent:
parent[key] = value
super().__init__(
environment,
parent,
name,
blocks,
globals,
)
self._context_class = _Context
return self._context_class
[docs]
async def from_file(self, file_path: Path) -> Template:
"""
Create a :py:class:`jinja2.Template` out of the given Jinja2 file path.
This method is intended for rendering individual files once. It **MUST NOT**
be used for reusable templates.
"""
async with aiofiles.open(file_path) as f:
template_source = await f.read()
template_code = self.compile(
template_source, filename=str(file_path.expanduser().resolve())
)
return self.template_class.from_code(self, template_code, self.globals)
@pass_context
def _gettext(self, context: Context, message: str) -> str:
return context_localizer(context).gettext(message)
@pass_context
def _ngettext(
self, context: Context, message_singular: str, message_plural: str, n: int
) -> str:
return context_localizer(context).ngettext(message_singular, message_plural, n)
@pass_context
def _pgettext(self, context: Context, gettext_context: str, message: str) -> str:
return context_localizer(context).pgettext(gettext_context, message)
@pass_context
def _npgettext(
self,
context: Context,
gettext_context: str,
message_singular: str,
message_plural: str,
n: int,
) -> str:
return context_localizer(context).npgettext(
gettext_context, message_singular, message_plural, n
)
def _init_globals(self) -> None:
self.globals["app"] = self.project.app
self.globals["project"] = self.project
today = datetime.date.today()
self.globals["today"] = Date(today.year, today.month, today.day)
# Ideally we would use the Dispatcher for this. However, it is asynchronous only.
self.globals["public_css_paths"] = [
path
for extension in self.project.extensions.flatten()
if isinstance(extension, CssProvider)
for path in extension.public_css_paths
]
self.globals["public_js_paths"] = [
path
for extension in self.project.extensions.flatten()
if isinstance(extension, JsProvider)
for path in extension.public_js_paths
]
self.globals["entity_contexts"] = EntityContexts()
self.globals["localizer"] = DEFAULT_LOCALIZER
def _init_extensions(self) -> None:
for extension in self.project.extensions.flatten():
if isinstance(extension, Jinja2Provider):
self.globals.update(extension.globals)
self.filters.update(extension.filters)
self.tests.update(extension.tests)
[docs]
@final
class Jinja2Renderer(Renderer):
"""
Render content as Jinja2 templates.
"""
[docs]
def __init__(self, environment: Environment, configuration: ProjectConfiguration):
self._environment = environment
self._configuration = configuration
@override
@property
def file_extensions(self) -> set[str]:
return {".j2"}
[docs]
@override
async def render_file(
self,
file_path: Path,
*,
job_context: JobContext | None = None,
localizer: Localizer | None = None,
) -> Path:
destination_file_path = file_path.parent / file_path.stem
data: MutableMapping[str, Any] = {}
if job_context is not None:
data["job_context"] = job_context
if localizer is not None:
data["localizer"] = localizer
try:
relative_file_destination_path = destination_file_path.relative_to(
self._configuration.www_directory_path
)
except ValueError:
pass
else:
resource = "/".join(relative_file_destination_path.parts)
if self._configuration.locales.multilingual:
resource_parts = resource.lstrip("/").split("/")
if resource_parts[0] in (
x.alias for x in self._configuration.locales.values()
):
resource = "/".join(resource_parts[1:])
data["page_resource"] = f"/{resource}"
template = await self._environment.from_file(file_path)
rendered = await template.render_async(data)
async with aiofiles.open(destination_file_path, "w", encoding="utf-8") as f:
await f.write(rendered)
await aiofiles_os.remove(file_path)
return destination_file_path