Baseclass for all loaders. Subclass this and override `get_source` to
implement a custom loading mechanism. The environment provides a
`get_template` method that calls the loader's `load` method to get the
:class:`Template` object.
A very basic example for a loader that looks up templates on the file
system could look like this::
from jinja2 import BaseLoader, TemplateNotFound
from os.path import join, exists, getmtime
class MyLoader(BaseLoader):
def __init__(self, path):
self.path = path
def get_source(self, environment, template):
path = join(self.path, template)
if not exists(path):
raise TemplateNotFound(template)
mtime = getmtime(path)
with open(path) as f:
source = f.read()
return source, path, lambda: mtime == getmtime(path)
| t.Tuple[str, t.Optional[str], t.Optional[t.Callable[[], bool]]] jinja2.loaders.BaseLoader.get_source |
( |
|
self, |
|
|
"Environment" |
environment, |
|
|
str
|
template |
|
) |
| |
Get the template source, filename and reload helper for a template.
It's passed the environment and template name and has to return a
tuple in the form ``(source, filename, uptodate)`` or raise a
`TemplateNotFound` error if it can't locate the template.
The source part of the returned tuple must be the source of the
template as a string. The filename should be the name of the
file on the filesystem if it was loaded from there, otherwise
``None``. The filename is used by Python for the tracebacks
if no loader extension is used.
The last item in the tuple is the `uptodate` function. If auto
reloading is enabled it's always called to check if the template
changed. No arguments are passed so the function must store the
old state somewhere (for example in a closure). If it returns `False`
the template will be reloaded.
Reimplemented in jinja2.loaders.FileSystemLoader, jinja2.loaders.PackageLoader, jinja2.loaders.DictLoader, jinja2.loaders.FunctionLoader, jinja2.loaders.PrefixLoader, jinja2.loaders.ChoiceLoader, sphinx.jinja2glue.SphinxFileSystemLoader, sphinx.jinja2glue.BuiltinTemplateLoader, and sphinx.util.template.SphinxTemplateLoader.