diff options
Diffstat (limited to 'venv/lib/python3.8/site-packages/flask/templating.py')
-rw-r--r-- | venv/lib/python3.8/site-packages/flask/templating.py | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/flask/templating.py b/venv/lib/python3.8/site-packages/flask/templating.py new file mode 100644 index 0000000..618a3b3 --- /dev/null +++ b/venv/lib/python3.8/site-packages/flask/templating.py @@ -0,0 +1,219 @@ +from __future__ import annotations + +import typing as t + +from jinja2 import BaseLoader +from jinja2 import Environment as BaseEnvironment +from jinja2 import Template +from jinja2 import TemplateNotFound + +from .globals import _cv_app +from .globals import _cv_request +from .globals import current_app +from .globals import request +from .helpers import stream_with_context +from .signals import before_render_template +from .signals import template_rendered + +if t.TYPE_CHECKING: # pragma: no cover + from .app import Flask + from .sansio.app import App + from .sansio.scaffold import Scaffold + + +def _default_template_ctx_processor() -> dict[str, t.Any]: + """Default template context processor. Injects `request`, + `session` and `g`. + """ + appctx = _cv_app.get(None) + reqctx = _cv_request.get(None) + rv: dict[str, t.Any] = {} + if appctx is not None: + rv["g"] = appctx.g + if reqctx is not None: + rv["request"] = reqctx.request + rv["session"] = reqctx.session + return rv + + +class Environment(BaseEnvironment): + """Works like a regular Jinja2 environment but has some additional + knowledge of how Flask's blueprint works so that it can prepend the + name of the blueprint to referenced templates if necessary. + """ + + def __init__(self, app: App, **options: t.Any) -> None: + if "loader" not in options: + options["loader"] = app.create_global_jinja_loader() + BaseEnvironment.__init__(self, **options) + self.app = app + + +class DispatchingJinjaLoader(BaseLoader): + """A loader that looks for templates in the application and all + the blueprint folders. + """ + + def __init__(self, app: App) -> None: + self.app = app + + def get_source( + self, environment: BaseEnvironment, template: str + ) -> tuple[str, str | None, t.Callable[[], bool] | None]: + if self.app.config["EXPLAIN_TEMPLATE_LOADING"]: + return self._get_source_explained(environment, template) + return self._get_source_fast(environment, template) + + def _get_source_explained( + self, environment: BaseEnvironment, template: str + ) -> tuple[str, str | None, t.Callable[[], bool] | None]: + attempts = [] + rv: tuple[str, str | None, t.Callable[[], bool] | None] | None + trv: None | (tuple[str, str | None, t.Callable[[], bool] | None]) = None + + for srcobj, loader in self._iter_loaders(template): + try: + rv = loader.get_source(environment, template) + if trv is None: + trv = rv + except TemplateNotFound: + rv = None + attempts.append((loader, srcobj, rv)) + + from .debughelpers import explain_template_loading_attempts + + explain_template_loading_attempts(self.app, template, attempts) + + if trv is not None: + return trv + raise TemplateNotFound(template) + + def _get_source_fast( + self, environment: BaseEnvironment, template: str + ) -> tuple[str, str | None, t.Callable[[], bool] | None]: + for _srcobj, loader in self._iter_loaders(template): + try: + return loader.get_source(environment, template) + except TemplateNotFound: + continue + raise TemplateNotFound(template) + + def _iter_loaders(self, template: str) -> t.Iterator[tuple[Scaffold, BaseLoader]]: + loader = self.app.jinja_loader + if loader is not None: + yield self.app, loader + + for blueprint in self.app.iter_blueprints(): + loader = blueprint.jinja_loader + if loader is not None: + yield blueprint, loader + + def list_templates(self) -> list[str]: + result = set() + loader = self.app.jinja_loader + if loader is not None: + result.update(loader.list_templates()) + + for blueprint in self.app.iter_blueprints(): + loader = blueprint.jinja_loader + if loader is not None: + for template in loader.list_templates(): + result.add(template) + + return list(result) + + +def _render(app: Flask, template: Template, context: dict[str, t.Any]) -> str: + app.update_template_context(context) + before_render_template.send( + app, _async_wrapper=app.ensure_sync, template=template, context=context + ) + rv = template.render(context) + template_rendered.send( + app, _async_wrapper=app.ensure_sync, template=template, context=context + ) + return rv + + +def render_template( + template_name_or_list: str | Template | list[str | Template], + **context: t.Any, +) -> str: + """Render a template by name with the given context. + + :param template_name_or_list: The name of the template to render. If + a list is given, the first name to exist will be rendered. + :param context: The variables to make available in the template. + """ + app = current_app._get_current_object() # type: ignore[attr-defined] + template = app.jinja_env.get_or_select_template(template_name_or_list) + return _render(app, template, context) + + +def render_template_string(source: str, **context: t.Any) -> str: + """Render a template from the given source string with the given + context. + + :param source: The source code of the template to render. + :param context: The variables to make available in the template. + """ + app = current_app._get_current_object() # type: ignore[attr-defined] + template = app.jinja_env.from_string(source) + return _render(app, template, context) + + +def _stream( + app: Flask, template: Template, context: dict[str, t.Any] +) -> t.Iterator[str]: + app.update_template_context(context) + before_render_template.send( + app, _async_wrapper=app.ensure_sync, template=template, context=context + ) + + def generate() -> t.Iterator[str]: + yield from template.generate(context) + template_rendered.send( + app, _async_wrapper=app.ensure_sync, template=template, context=context + ) + + rv = generate() + + # If a request context is active, keep it while generating. + if request: + rv = stream_with_context(rv) + + return rv + + +def stream_template( + template_name_or_list: str | Template | list[str | Template], + **context: t.Any, +) -> t.Iterator[str]: + """Render a template by name with the given context as a stream. + This returns an iterator of strings, which can be used as a + streaming response from a view. + + :param template_name_or_list: The name of the template to render. If + a list is given, the first name to exist will be rendered. + :param context: The variables to make available in the template. + + .. versionadded:: 2.2 + """ + app = current_app._get_current_object() # type: ignore[attr-defined] + template = app.jinja_env.get_or_select_template(template_name_or_list) + return _stream(app, template, context) + + +def stream_template_string(source: str, **context: t.Any) -> t.Iterator[str]: + """Render a template from the given source string with the given + context as a stream. This returns an iterator of strings, which can + be used as a streaming response from a view. + + :param source: The source code of the template to render. + :param context: The variables to make available in the template. + + .. versionadded:: 2.2 + """ + app = current_app._get_current_object() # type: ignore[attr-defined] + template = app.jinja_env.from_string(source) + return _stream(app, template, context) |