Source code for spack.tengine

# Copyright 2013-2022 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
import itertools
import textwrap
from typing import List  # novm

import six

import llnl.util.lang

import spack.config
from spack.util.path import canonicalize_path

[docs]class ContextMeta(type): """Meta class for Context. It helps reducing the boilerplate in client code. """ #: Keeps track of the context properties that have been added #: by the class that is being defined _new_context_properties = [] # type: List[str] def __new__(cls, name, bases, attr_dict): # Merge all the context properties that are coming from base classes # into a list without duplicates. context_properties = list(cls._new_context_properties) for x in bases: try: context_properties.extend(x.context_properties) except AttributeError: pass context_properties = list(llnl.util.lang.dedupe(context_properties)) # Flush the list cls._new_context_properties = [] # Attach the list to the class being created attr_dict['context_properties'] = context_properties return super(ContextMeta, cls).__new__(cls, name, bases, attr_dict)
[docs] @classmethod def context_property(cls, func): """Decorator that adds a function name to the list of new context properties, and then returns a property. """ name = func.__name__ cls._new_context_properties.append(name) return property(func)
#: A saner way to use the decorator context_property = ContextMeta.context_property
[docs]class Context(six.with_metaclass(ContextMeta, object)): """Base class for context classes that are used with the template engine. """
[docs] def to_dict(self): """Returns a dictionary containing all the context properties.""" d = [(name, getattr(self, name)) for name in self.context_properties] return dict(d)
[docs]def make_environment(dirs=None): """Returns an configured environment for template rendering.""" if dirs is None: # Default directories where to search for templates builtins = spack.config.get('config:template_dirs', ['$spack/share/spack/templates']) extensions = spack.extensions.get_template_dirs() dirs = [canonicalize_path(d) for d in itertools.chain(builtins, extensions)] # avoid importing this at the top level as it's used infrequently and # slows down startup a bit. import jinja2 # Loader for the templates loader = jinja2.FileSystemLoader(dirs) # Environment of the template engine env = jinja2.Environment( loader=loader, trim_blocks=True, lstrip_blocks=True ) # Custom filters _set_filters(env) return env
# Extra filters for template engine environment
[docs]def prepend_to_line(text, token): """Prepends a token to each line in text""" return [token + line for line in text]
[docs]def quote(text): """Quotes each line in text""" return ['"{0}"'.format(line) for line in text]
def _set_filters(env): """Sets custom filters to the template engine environment""" env.filters['textwrap'] = textwrap.wrap env.filters['prepend_to_line'] = prepend_to_line env.filters['join'] = '\n'.join env.filters['quote'] = quote