lektor-website/packages/jinja-globals/lektor_jinja_globals.py

71 lines
2.7 KiB
Python

from email.utils import getaddresses
from typing import Optional
from markupsafe import Markup
from lektor.pluginsystem import Plugin
def mailto_link(email_address: str, default_link_text: Optional[str] = None) -> Markup:
"""Format an HTML link to a mailto: URL to ``email_address``.
``Email_address`` should be a string containing one or more
comma-separated RFC5322 addresses. Any *display-name*\\s included
in ``email_address`` will be stripped, before use in the
``mailto:`` URL. (RFC6068_ allows only *addr-spec*\\s in the
``mailto:`` URI.)
The link text will be formed from the *display-name*\\s extracted
from ``email_address``. If there are none, they the link text
will be taken from the value of the optional ``display_name``
parameter. If that is empty, the link text will be the value of
``email_address``.
Background
**********
This filter is useful for massaging a distributions "Author-email"
and "Author" metadata fields into a valid mailto link. Sometimes
the author's name gets folded into the "Author-email" field
(e.g. ``"Author Name <author@example.org>"``), and sometimes it is
separated out into the "Author" field.
According to PEP621_, when both author ``name`` and ``email`` are
specified in ``pyproject.toml``, both of those wind up in the
"Author-Email" metadata field. In that case, the "Author" metadata
field remains empty.
In constrast, historically, (e.g. in ``setup.py`` based projects) it
seems to have been common practice to put the author's name in
"Author" and their email in "Author-Email". (Of note, the `Core Metadata
Spec<mdspec_>`_ is not particularly opinionated on whether the
author name(s) should go into "Author", "Author-Email", or both.)
.. _PEP621: https://peps.python.org/pep-0621/#authors-maintainers
.. _mdspec: https://packaging.python.org/en/latest/specifications/core-metadata/#author
.. _RFC6068: https://datatracker.ietf.org/doc/html/rfc6068
"""
addresses = getaddresses([email_address])
addr_specs = ", ".join(addr_spec for name, addr_spec in addresses if addr_spec)
if not addr_specs:
return Markup("")
link_text = ", ".join(name for name, addr_spec in addresses if name)
if not link_text:
link_text = default_link_text or addr_specs
return Markup('<a href="mailto:{addr_specs}">{link_text}</a>').format(**locals())
class JinjaGlobalsPlugin(Plugin):
name = "Jinja Globals"
description = "Custom Jinja globals and filters for lektor-website."
def on_setup_env(self, **extra):
self.env.jinja_env.globals.update(
{
"mailto_link": mailto_link,
}
)